The Living Cask

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The Living Cask:
Re-discovering an ancient hobby

Keeping oak barrels at home filled with an assortment of alcoholic beverages is an ancient custom. Keeping the cask at least half full and replenishing it with “fresh stock” is called a Solera process.

A traditional solera system in a cellar would have a barrel stack ranging from the youngest at the top to the oldest at the bottom. A proportion of whisky (in Jerez it would sherry) is removed from the barrels in the bottom row for bottling. These are in turn topped up from the row above and so on. The very top row is topped up with the youngest whisky. In this way a very consistent product over many years can be produced. The bottom barrels will thus always contain a portion of the original whisky used in the solera. Nowadays barrels are stored side by side and the product is transferred with a pump.

Whisky, Brandy, Port, Sherry, Mead and also beer –especially Lambic, Stale old ale and Flanders red – lends itself well to this keeping method. For now I want to introduce you to Draymans Solera Whisky. For the last few years the living cask has been my new hobby at home and has now been transformed into a small whisky business. It is a perfectly legal hobby to “make” your own whisky at home – so long as “make” is defined as the blending of whiskies which you have bought from say Makro or any other liquor store and then maturing it in your own cask or casks. Obviously you can’t sell it either, unless you have an alcohol manufacturing license.

“Vatted Malt” means a blend (or vatting) of only single malt whiskies from various distilleries. The advent of vatting demonstrates an understanding of maturation and shows how the first commercial blenders were trying to impose quality and consistency in their products. Vatting was widely practiced in private homes. In 1864, Charles Tovey wrote of how, “in a gentleman’s cellar” one would find a hogshead (must have had a lot of friends!) containing four or five malts (whisky) which would be replenished with “any whisky that is particularly approved (of)” when the volume dropped below half. This solera method of vatting was expanded upon by Professor George Saintsbury in his Notes on a Cellar book (1920). The Professor’s cask contained Clynelish, The Glenlivet, Glen Grant, Talisker, and Islay. The idea has been revived by Richard Joynson at Loch Fyne, whose “Living Cask” has been evolving since 1988.

Vatted malts are more than just single malt blends without adding grain whisky, as practiced by the puristic portion of its followers. Vatted malts are about combining different levels of complexity to create different flavour combinations. For example, Glenfiddich Solera Reserve 15-year old is stored in huge Solera vats that, in common with those in Jerez are always kept at least half-full. This method of fractional blending not only gives consistency between bottlings but builds in extra layers of flavour – far more complex than conventional finishing.

Most Speyside whiskies have gradually dropped their peating levels in the past few decades and many are also noticeably lighter in style. The complex, almost oily character and the combination of floral notes, smoke and silky palate so valued by devotees of the old style, have largely disappeared. Bearing in mind that maturation accounts for 70% of the flavour of any whisky, you can now recreate a complex whisky at home with vatting.

If “Vatted Malt” implies using only single malt whisky, then perhaps “Solera Blend” would be an appropriate term to use where a mixture of both malt and grain whisky is used in a Solera cask. A “Solera Blend” is a more affordable approach to the hobby and allows the blender the freedom to use malt-whisky, grain-whisky and blends thereof to create his own unique flavours.

The pure indulgence and utmost pleasure of pouring your own dram of rich, golden, solera family reserve whisky directly from the cask can not easily be conveyed on paper. There are quite a few very good Irish, Scotch and Canadian whiskies locally available at around R80/bottle that can be valued contributors to your own Living Cask.

Brewing with antifoam: is it good or bad?

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Brewing with anti foam: is it good or bad?

By Moritz Kallmeyer
Chief Brewer of Drayman’s Microbrewery, Silverton, Pretoria, January 2013

I first read about anti foam in the book Basic Brewing Science by Dr Trevor Wainwright. He classifies it as a processing aid, meaning no traces of the additive is found in the final beer. I view malt husks in much the same light. I’ve been using it for about a year now and probably would never go without it again. During fermentation CO2 produced causes the beer to foam. When the foam collapses at the end of fermentation, a considerable amount of the material forming the bubbles (mainly protein and hop components) is left on the walls of the fermented – and inside the domed roof in case of a closed fermenter. As a result the packaged beer (especially on high adjunct ratio beers) may not be able to form a good foam head and some of the bittering material is lost in the fermenter. The material deposited on the walls is often difficult to clean off and large fermenters are needed to prevent over-foaming. Even over sized fermenters are no guarantee to prevent over-foaming and this always results in beer loss and cleaning problems. Walking into the brewery in the morning, finding half your brew on the floor is not a pretty sight.

At home brew level there would certainly be no more clogged bubblers or blocked blow off tubes! When there is fat from food or lipstick on a beer glass it destroys beer foam. Anti foams are food grade silicone oils or hydrocarbon oils with additives that act in the same way and are normally preserved with sulfur dioxide. Anti foam allows CO2 to escape from the beer without forming stable bubbles. The brand name that I use is called “Fermcaps” and contains an emulsion of 20% Dimethyl Polysiloxane. Since I have experienced frequent problems with boil-overs at Drayman’s (because of an undersized kettle), I was delighted to learn that antifoam is also used in the wort kettle to prevent over foaming and to allow the water to evaporate more quickly. The antifoam added are absorbed onto the yeast and filter material and none is supposedly left in the finished beer.

The word antifoam is thus a bit of a misnomer because the foam on the end-product beer is usually improved. The reason is that less of the head forming protein which is good for foam has been lost during fermentation and transfers.

Other advantages which I have discovered:

  1. Improved yeast separation at the end of primary fermentation which allows easier collection into buckets.
  2. More complete yeast removal from the FV is possible because of the slipping effect, lack of sticky adherence to the cone.
  3. Beer drops bright even in the primary FV during the diacetyl rest period before racking.
  4. More complete fermentation, yeast tend to stay in suspension for longer.
  5. Faster transfers due to no foaming.
  6. Improved filtration due to more yeast that is removed at primary yeast collection stage and less work for the added finings.
  7. Lower hopping rate to achieve the same bitterness level.
  8. Those who use plain caustic in a CIP system know how much time is wasted with foaming. When cleaning the fermenter I found a carry over of antifoam into the CIP caustic tank resulting in less caustic wastage and more efficient cleaning.
  9. For reasons unknown the caustic storage tank also drops bright which allows me to purge the bottom of old dregs, top up the strength and re-use the caustic almost continuously.

Warning! Reception vessels to be CO2 blanketed or use counterpressure. Because of a lack of foam coverage during transfers, there is a risk of oxidation!

Like with all processing aids the challenge is to find the absolute minimum dosing rate for maximum efficiency. Like usual I question any suppliers dosing rate! With Fermcaps which I have been using, I initially halved the suggested dosing rate and still picked up problems. I also added Fermcaps to both the boiler and the FV, thinking it would “degrade” during boiling. In the supplier’s spec sheet, no mention is made of the fact that if you added antifoam to the kettle there is no need to add it to the fermenter again. I found that there is a larger than anticipated carryover effect, because of the adherence to the yeast cells – which is subsequently re-pitched. After a few batches the beer had a very faint but certain oiliness to it and the foam head was affected negatively. I thus followed my own brewer’s instinct and kept cutting back until reaching my current optimum dose rate of 1 1/2 ml antifoam per 900L wort kettle volume. Just add it to the kettle before boilstart.

My own recommendation is thus that you can use antifoam with a clean conscience and enjoy a more relaxed brewing day. No nasty boil over surprises, no early morning beer flooded basements, piece of mind as far as CIP is concerned and a beer in your hand topped with more brilliant white foam bubbles!

Beer flavour terminology

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BEER FLAVOUR TERMINOLOGY

Class 1 – Aromatic, fragrant, floral, fruity

Subclass 0130 – Estery

Esters are a class of compounds that are formed by the combination of a fusel alcohol with a fatty acid, producing many powerful but pleasant fruity aromas and tastes. It is common to most fermented products, including wine and whiskey

Synonyms for esters are vinous and winy which are very aromatic-type, positive flavours. There are at least 90 esters identified in beer. Esters are a by-product of fermentation. During the yeast growth stage, fatty acids are built up into sterols and other compounds that make up, amongst other structures, the cell wall of the yeast cell. If the wort lacks oxygen this cannot happen and the yeast cell will, instead attach these acids to alcohols, making esters. Esters also act as solvents to keep flavours in solution that are not soluble in water.

How to control ester formation

  1. The wort must be strongly aerated (ideally oxygenated) at the beginning of fermentation.
  2. The higher the gravity of the wort, the less oxygen it will hold – this is why high gravity beers always feature a disproportionate amount of esters. To hold them in check in high gravity brewing operations brewers inject pure oxygen into the wort at the start of fermentation. This unfortunately raises the diacetyl level again but the brewer can cope with this later on in fermentation.
  3. Ester formation is higher if the wort temperature at pitching and during fermentation is higher.
  4. The higher the pitching rate the lower the ester formation – because the yeast needs to reproduce less before fermentation begins. Esters and other by-products are created mainly during the growth rate and a high pitching rate will result in a large proportion tired yeast cells, especially after several repitchings. As a result, each fermentation is less vigorous than before, takes more time, and often yields a high terminal gravity. The best practice is thus to pitch a proper amount (1 litre thick slurry per hectoliter) of active, viable yeast into thoroughly oxygenated wort.
  5. If you get a good fermentation but unacceptable amounts of by-products, change to a “cleaner” strain of yeast. Some yeast strains are notorious for their high ester formation and are specifically chosen to brew for example a very estery Old Ale or Barley Wine.
  6. The tight-pot fermentation system controls ester formation. There is more ester formation in stirred or continious fermentation systems, which takes about two and a half to three days.
  7. If you add lipids or fatty acids, you get more ester formation. You can experiment with this by taking the squeezings from your spent grains and adding it to the wort. You will get a faster fermentation and more esters. This method unfortunately leads to oxidative flavours.

Esters predominant in beer

Ethyl Acetate – is the product of the reaction between ethanol and acetic acid (or acetyl CoA, which is called activated acetic acid). This ester has light fruity or solventlike notes (Commercial acetone has a use as nail polish remover) Ethyl Acetate is the ester with the highest concentration.

Isoamyl Acetate – is an ester made up from larger acids andIor higher alcohol’s and tend to have a powerful fruity banana or peardrop aroma and taste. Can be tasted at 2 ppm.

Ethyl Butyrate – aroma of pineapple.

Ethyl Hexanoate – applelike with notes of aniseed.

British ales yeast’s often produce noticeable amounts of fruit esters and are highly prized for this quality. A good brewer will control the amount of ester production in such a way that it does not distract from the drinking pleasure of his ales. Lager brewers on the other hand will go out of their way to eliminate esters from the flavour profile of their lager beer.

Notes compiled by: Moritz Kallmeyer

Craftbrewer

Saison

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SAISON

(Biere Belge Belgian Beer)
By Moritz Kallmeyer
Chief Brewer Drayman’s Craftbrewery, Silverton Pretoria, January 2003

Introduction & History

In French-speaking Wallonia, especially the province of Hainut, they feel that their beers are overlooked and underrated. They complain that no one in Flanders has heard of their ales. It would certainly be a tragedy if the beers of this region were to disappear, especially the style known as saison. Clearly they are seasonal beers and were brewed – and sometimes are still brewed by farmers who make them in the winter and store them for drinking during the hot summers, much like the bières de garde across the border in France. Saison are now made all year round. The name is another reminder that before refrigeration, it was difficult to brew in warm weather. The batch specifically brewed in spring to be laid down as a provision for the summer was known as la saison de mars (like the German Märzen) or sometimes Vieille (old) Provision – a term that dates from the time when these stored seasonal beers were an important part of the farmers nutrition and diet. These beers were traditionally brewed to be served at family meals.

It had to be sturdy enough to last for some months but not to strong to be a summer and harvest time thirst quencher. The classic brewery of Saison is Du Pont and has been run by the Du Pont family since the 1920’s.

Brewing methods and flavour descriptions

Body

Saisons are made to have a medium body and crispness and to deliver a robust flavour and big fruity character. The brewers of old sometimes worked to produce mashes that were only partly fermentable (to aid body).

Mash

One technique was to take the first extraction of juices from the malt at cold temperatures, producing milky turbid wort that was heated separately, and then added back for the mash. Sometimes the brewers used a small proportion of spelt (a variety of wheat that gives a very fine flour – or oats or rice both used raw).

Hops

Saisons flavour is heightened by a generous dose of hops usually of the East Kent Goldings and Styrian Goldings variety. Heavy hopping produces intense peppery spiciness. One brewer describes it as an aroma reminiscent of liquid snuff! Some beers are dry hopped.

Malts

In today’s saisons pale malts of Belgian and English varieties are predominantly used – perhaps gaining some colour in a long boil. Some artisan saison brewers still use dark and caramalts producing what we might call a dark saison.

Spices

The classic spiced saison producer is the Brasserie à Vapeur (small coal fired steam powered brewery). The beer is Saison de Pipaix 6.5% Alc and it is described as a fresh-tasting, fruity tart beer seasoned with six spices including star anise, black pepper, coriander, dried orange peel and medicinal lichen. Some brewers also use ginger along with the hops.

Fermentation

Saisons are top fermented beers. Traditionally fermentation was restrained by multistrain yeasts that worked quickly but not very exhaustively. These beers were also at least partly fermented in the cask. Today either Franco, English or Belgian strains – usually hybrids are used. These beers often have a warm conditioning in metal tanks at the brewery (8-13°C) and usually secondary fermentation in the bottle.

Foods to serve with

Most of these beers nowadays have a distinctive orange colour and a dense rocky head. Saisons have a refreshing crispness and lively carbonation with hoppy fruity flavours often with citric notes. Their tartness and fruitiness make them an excellent accompaniment to duck, hearty stews, spicy sausages or lamb with juniper berries.

Gravity

Gravity of saisons is typically in the 1050-1055 range – although some Christmas specials weigh in at above 1065.

About Aldehydes

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About Aldehydes

If you look at the reactions in the conversion of glucose to alcohol and CO2 (Glycolysis pathway), you will see that phosphopyruvic acid is converted into acetaldehyde (a Glycolysis intermediate) which again is converted into ethanol. An all malt wort with OG 1048 which is used in the production of a standard beer will produce 7mg/l acetaldehyde as a normal fermentation secondary product.

Acetaldehyde is easily detectable in beer which has not completed the maturation or conditioning stage, which could be as short as 48 hours in beers not of the lager type. Such beer is often called “green beer” not referring to its colour, but to the fact that the flavour is not fully mature. Together with diacetyl and H2S, acetaldehyde is the most noticeable green beer flavour. Acetaldehyde contributes an apple-like taste which if detected is considered an undesirable off-flavour. As the beer matures most of the acetaldehyde is taken back into the yeast cell and reduced to ethanol. Keto acids (of which there is a very small amount in beer) are formed during carbohydrate catabolism. Their importance is rather as intermediates in the formation of the related amino acids, aldehydes, acids, esters and alcohols. These aldehydes (like acetaldehyde) are reduced to the corresponding alcohols like isoamyl alcohol, 2-phenylethanol and the ester ethyl acetate – all important beer flavour contributors. A very important factor in the removal of green beer flavours is that it depends on having enough live, well adapted, active, yeast present in suspension to take the compounds into cells and reduce them towards the end of primary fermentation and the beginning of secondary fermentation.

Krausening will increase maturation time because it creates a new peak of fermentation byproducts which will then have to be reduced again. Flavour problems are caused by too early separation (flocculation) of the yeast, because the oxo compounds mentioned earlier can then not be removed. Abnormal fermentations like long lag phases, yeast that “run out of steam” before the required amount of fermentables are used (hung fermentation) or trailing fermentations all cause flavour problems. Abnormal fermentations can also be caused by bacterial contaminants such as Zymomonas and non compliant appy’s, but the pathway to form acetaldehyde stays the same. Which brings me to the conclusion that 1st and 2nd batch fermentations with the same yeast, freshly propagated from smackpacks, vials or dried yeast, (even if a large starter was made) is not normal and ferments a beer either of “non-matching” quality or with flavour problems. To avoid this, the brewers rule is to add at least a quarter of previous (old) generation yeast together with the freshly propagated yeast starter. Practical implications to home brewers is to stick to the same beerstyle at least 3 times in short succession with serial re-pitching to give the new yeast time to adapt to their specific wort makeup, brewing setup and fermentation conditions, before changing to a new beerstyle.

Are we perhaps drinking our beer to fresh?

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Are we perhaps drinking our beer to fresh?

While at my stall at the Food and Drink Festival an elderly lady brought me a dumpy bottle of beer in a shape I’ve never seen before. She asked me if I would be so kind to test this (the last bottle) of a brew her late husband brewed more than 20 years ago! This I took as quite a privilege because I have never drank a beer that old. Apparently she did ask Jeremy Mansfield but he did not respond. So I took it home and after standing quiet for a week in my fridge I taste tested it.

The nose was the first clue that this was indeed a very mature beer. It had a rich liqueur brandy, olroso sherry aroma which was quite appetizing. It was obviously brewed with malt extract because the “extract” aroma so typical in kit beers came through quite strong. The flavor was stunningly dry (with very faint oxidation) and a slight acidity that combined very well.

The dryness and acidity reminded me of a bottle of wood matured Rodenbach Belgium ale.

The carbonation and head was perfect for a beer that old. The lack of any yeast off flavors was surprising because the yeast and protein residue in the bottle was pitch black!

Ester Production in Yeast

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Ester Production in Yeast
By Moritz Kallmeyer
Chief Brewer of Drayman’s Craftbrewery, Silverton Pretoria, April 2006

Introduction:

The opposite of what we read is usually true regarding the increase in ester production during the growth phase. Ester production is directly related to biomass production. Everything that increases biomass production (intense aeration, stirring, sufficient lipid etc.) decreases ester production. The more biomass is produced, the more acetyl Co-enzyme A is used for and therefore not available for ester production.

Question: Does high temperature early in fermentation, during the growth phase increases ester production?
Answer: No, during the growth phase ester production is reduced because acetyl- CoA is used (tied up) for yeast growth and is not available for ester production.

Question: Does higher pitching rates result in higher ester formation?
Answer: Yes, because there is less growth before they reach the stationary phase.

Question: Does higher initial gravity result in higher ester production?
Answer: Yes, because · There are in general more metabolites produced that can react with each other and · Higher gravity worts hold less O2 – unless the brewer specifically compensates for that.

Question: Does low DO (dissolved wort oxygen) increase ester formation?
Answer: Yes, it inhibits yeast growth, thus increases ester production. Dropping wort DO from 8ppm to 3ppm has a four fold increase in ester.

Question: Is it better to pitch at warmer temperature than at cooler temp for ester control in lager beer?
Answer: Pitching at warmer temperature will begin the production of more yeast. While the yeast is growing there will be less ester production (see above). You will need adequate cooling to control fermentation temperature. Pitching at cooler temperatures with a higher pitching rate will result in less yeast production and more ester production. It would be difficult to speculate which would end up with the most esters.

Question: Does a low pitching rate produce more ester?
Answer: No. Low pitching rate result in less esters. Pitching rate would vary as a means to increase or decrease total fermentation time and could be influenced by shortage of fermenter space. If lack of refrigeration or temperature control is a problem the fermentation needs to be spread out over a longer period by pitching with less yeast and restrict O2 addition in order to control yeast growth and thus fermentation temperature.

Question: Would agitation or stirring of a normal gravity wort increase ester production?
Answer: No, stirring of normal gravity wort would decrease ester production.

Question: How about high gravity wort?
Answer: Stirring in high gravity fermentation would increase ester production.

Question: Does tall fermenters produce less esters than shorter and wider fermenters?
Answer: Yes. Tall fermenters produce less esters than short fermenters because of CO2 buildup. At 0.5 atmospheres the pressure begins to exert a negative effect on yeast growth.

Question: Does wort which contains higher maltose component have lower ester production?
Answer: Yes. The use of high maltose syrup as an adjunct instead of glucose, sucrose or fructose adjuncts will give lower ester formation. New very high maltose syrups of 70%+ are now becoming available. Higher maltose wort gives higher yeast viability and thus increased growth.

Enjoying a Beer

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Enjoying a Beer

By Moritz Kallmeyer
Chief Brewer of Drayman’s  Craftbrewery & Distillery, Silverton Pretoria,  July 2006.

Nowadays I usually only have one 500ml beer per day (got to leave space for a wee dram later the evening) and I therefore aim to maximize the pleasure of that beer. The enjoyment of the beer for me begins with the preparation of an elegant, appropriate glass. I listen for that reassuring hiss as I open the top, and then continue with the gentle pour down the side of the glass. I wait for the foam to subside (visually the colour, foam and bubbles all arouse the senses) then top it up to a rich dense head.

I put it down in front of me, refraining from taking a sip right away and study the beer in quiet contemplation – the brilliancy and shades of colour, the condensation on the glass, the bubbles lazily rising up to the rich, dense, white head. I then bring the glass to my nose, appreciating the spicy hop bouquet and sweet malt aromas. Now my senses are awakened in eager anticipation for that first mouthful – which I roll around in my mouth making sure it covers all parts. While enjoying the beer I think about all the hard work everybody in the barley fields, at the maltsters and at the brewery has put into this beer to make it a success.

For me the pleasure of beer enjoyment lies more in the journey, not so much in its destination as it is consigned to the stomach. As beer lovers we should educate people regarding drinking beer, more for the enjoyment – not for the effect.

Prost !
Moritz

Yeast Autolysis

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Yeast Autolysis
By Moritz Kallmeyer
Chief Brewer Drayman’s Craftbrewery, Silverton Pretoria, March 2005

Introduction:

The more I know about yeast, the more I realize I need to know more about yeast!

Any excess over need results in the formation of food reserves in the form of carbohydrates or fat. When given access to a plentiful supply of nutrition, plants like barley make barley starch in the seeds to provide the energy for germination. Yeast is no exception and energy reserves are found particularly in the form of the non-reducing disaccharide trehalose and the polysaccharide glycogen. These carbohydrates will have normally accumulated in cells at the end of brewery fermentation (when famine sets in). Both in storage and early in fermentation, yeast uses them as reserves to provide glucose for glycolysis. Brewers are thus cautioned to handle yeast correctly or the yeast may autolyze.

Definition:

Yeast autolysis or self-lysis is the breaking open or rupturing of the yeast cell and the transfer (leaking out) of undesirable substances and off-flavours to the beer. The flavour is described as yeast-bite, broth-like, meaty, sulphury and dirty diaper.

Reasons for autolysis:

  1. The cell membrane of any unhealthy cell can become more prone to lysis during fermentation if exposed to any stressor.
  2. Older yeast cells become weaker and less active with age and eventually their cell membranes rupture.
  3. Sudden exposure to shock caused by too rapid cooling or warming can cause some cells to lyse which would otherwise remain intact.
  4. If beer which contains yeast is stored for a long time, or when beer which still contains yeast when it leaves the brewery is kept for a long time before it is drunk.
  5. Poor storage conditions of cropped yeast. 6. Intentional acceleration of autolysis by heating the yeast to make autolysates for the food industry, such as Marmite.

Yeast and nutrition:

The composition of the environment influences the metabolic processes the yeast uses. Yeast has the ability to use a range of different sugars and even ethanol for growth. Fermentation with the goal to achieve beer can not be separated from yeast growth – and for growth to occur the brewer needs to supply the correct nutritional environment. If there is no growth there is no fermentation. Growing yeast never flocculate and flocculated yeast never grow.

Brewers yeast needs:

  1. Readily usable (assimilable) sources of carbon and nitrogen (FAN – free amino nitrogen) which they get from malt.
  2. B-vitamins from malt.
  3. Trace elements from malt and brewing water, namely ions of calcium, magnesium, zinc, phosphate and sulfate.
  4. Fermentable sugars, mainly the disaccharide maltose from malt which is transported into the cell and hydrolyzed to glucose. Lesser amounts of the monosaccharides, sucrose, glucose, fructose and the trisaccharide maltotriose .
  5. Molecular O2 in small amounts (1ppm O2 for every degree plato) supplied by the brewer at pitching referred to as wort DO (dissolved oxygen). If oxygen is supplied, yeast can manufacture (synthesize) unsaturated fatty acids and sterols on their own. These two compounds are irreplaceable constituents of cell membranes. If they are not present, yeast can not grow because they are unable to biosynthesize cell membranes.

Causes of stress in yeast:

  1. Extended period of cold storage before re-pitching.
  2. Inadequate temperature during cold storage.
  3. Poor temperature control during fermentation.
  4. Nitrogen starvation.
  5. Excessive re-pitching without cleaning.
  6. Vitamin and mineral deficiencies.
  7. O2 deficiencies.
  8. Low oxygen related lipid levels.
  9. Glucose / maltose ratio out of balance.
  10. CO2 toxicity.
  11. Ethanol toxicity.
  12. Contaminants accumulation.
  13. High gravity wort.
  14. Osmotic pressure shock.
  15. Low pH.
  16. Mutations.

    If yeast is stressed for whatever reason, it will stop growing.The flocculation mechanism is initiated as survival method. The cell surface change, they clump together and drop to the floor in a coma awaiting more energy. Autolysis always follows “hot on the heels” of flocculation.

The yeast cell membrane:

The cell membrane consists of a double layer of lipid molecules and proteins. Only small organic nitrogen compounds (amino acids and di- or tri-peptides) can be absorbed by yeast. Several flavour active compounds can pass out into the beer.

Structures in a yeast cell

*All have lipid membranes.

Dry Yeast Rehydration, it’s critical!

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Dry Yeast Rehydration, it’s critical!

By Moritz Kallmeyer
Chief Brewer Drayman’s Craftbrewery, Silverton Pretoria, March 2005

Each brand of ADY (active dry yeast) specify its own optimum rehydration temperature, ranging from 35°C to 40°C. As you drop the strike temp from 40°C to 15°C the yeast will leach out progressively more of its insides, damaging each cell. The yeast viability thus drops proportionally. At 40°C there is 100% recovery of the viable dry yeast while at 15°C there can be as much as 60% dead cells. The dried yeast cell wall is very fragile and it is essentially in the first minute, even seconds of rehydration that warm temperature is critical while it is reconstituting its cell wall structure. During these first initial minutes of rehydration, the yeast cell wall can not differentiate what passes through the wall. Materials which is toxic to the yeast at this stage like sugars, hop products and SO2 that the yeast normally can selectively prevent from passing through its cell wall, rush right in and seriously damage the cells. The moment the cell wall is properly reconstituted the yeast can regulate what goes in and out of the cell. This is why the suppliers warn against rehydration in wort, instead of water.

The water should be normal tap water ideally with 250-500ppm hardness present. The hardness is essential for a good recovery. This is the reason why distilled or de-ionized water should never be used. I further prefer the water to be carbon filtered to remove any chlorine and impurities, then boiled to sterilize and force chilled down to the required rehydration temperature. Ideally if you have access to it, the warm rehydration water should contain 0.5-1.0% yeast extract like Go-ferm from Lallamand.

Active dry yeast is dormant or inactive, not inert, so it should be kept refrigerated at all times at around 4°C. It will only loose 4% of its activity in a year if kept at this temperature. Remember to remove the package from the refrigerator early on brew day so it can naturally attemperate to the rehydration temperature. This prevents one stressor, temperature shock. I prefer to do the rehydration process in a hygienic polyethylene bucket. The yeast should be sprinkled into 10 times its own weight of rehydration water and gently folded in with a spoon to wet them. Oxygen is not needed at this stage so stirring should be avoided. After sitting for the recommended 15 minutes give it a vigorous whirl then again close the lid of the bucket lightly and leave it for 5 more minutes at the specified rehydration temperature. Built into each cell by the manufacturer is a large amount of glycogen and trehalose reserves that give the yeast a burst of energy to kick off the growth cycle when it is added to the wort. It is quickly metabolized and used up by the yeast within about 30 minutes of rehydration. There is no damage done to the yeast if it is not added to the main batch of wort within this period of time – you just do not get the benefit of that sudden burst of energy and lag times are likely to increase. The rehydrated yeast, being warm, should now be cooled to within 4°C of the wort before pitching. This attemperation is done over a brief period by adding in increments, a small amount of cold wort (removed earlier from the kettle and chilled) to the rehydrated yeast container. Rehydrated warm yeast pitched into cold wort will cause many of the yeast cells to produce petite mutants that will never grow or ferment properly and will cause them to produce H2S.

Some ADY manufacturers recommend slightly lower than normal wort aeration while others argue that most ADY yeast actually require no O2 addition for successful, average gravity wort fermentation. There are enough lipids built into the cell at the yeast factory. It will however need O2 addition on the next re-pitching.

To Mash or not to Mash Kurz/Hoch

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To Mash or not to Mash Kurz / Hoch
By Moritz Kallmeyer
Chief Brewer of Drayman’s Craftbrewery, Silverton Pretoria, October 2004

Introduction

The Kurz /Hoch method of mashing was recently advocated when both studies at Weihenstephan State University and reports by Michael J. Lewis and Tom W. Young (Brewing, Second edition, p.244) confirmed the following: wort dextrins have no flavour of their own and are not viscous enough in solution to account for the perceived (sensory) viscosity or “body” of beer. Something else (the subject of current research) contributes to the perception of “body” in beer, not dextrins. It is thus assumed that traditional complex mashing regimes which were done to promote dextrin formation in order to promote “body” are redundant. The main question to ask if you are considering mashing Kurz/ Hoch is: “What malt am I going to use?” The Kurz /Hoch mashing method is not suitable for cereal adjunct inclusions.

1. Mash short

With the great excess of enzymes in modern malt, conversion can be achieved a lot faster than once believed (remember almost all fully modified malts are designed for big brewers with high cereal adjunct rates). The less time spent mashing the better. 20 Minutes maximum at conversion temperature. The underlying principal is to create maximum extraction with minimum grain contact time.

2. Mash high

Mashing is a beta-amylase sensitive (and therefore a fermentability sensitive) event. . The following arguments demonstrate that mash conditions, especially temperature range must primarily be chosen to accommodate the enzyme content and degree of modification of the malt.

  • When malt is poorly modified (or not as well modified) the brewer’s window is higher on the temperature scale, say 67-70°C. Thus poorly modified malt must be mashed hotter than well-modified malt to achieve adequate extract yield. To produce the required level of fermentability, the malt must also have sufficient enzymes (especially beta-amylase) to survive the higher mash temperatures used. This malt is thus suitable for Kurz/ Hoch mashing.
  • Brewers Window: It is the temperature range where both Alpha- (AA) and Beta-amylase (BA) work “in concert” to create the required degree (for beer type) extraction and fermentability. * When malt is thoroughly modified (well-modified) with just adequate enzymes the brewers window of mashing temperature is lower on the temperature scale, say 65-67°C.
  • No respected maltster will produce malt which is both poorly modified and low in enzyme so we can exclude that option.
  • Traditional British two row malt, for which the longer rest, single temperature infusion mash was developed are very well-modified malts (but with quite low enzyme content) which can only be mashed successfully at low temperatures (say 65°C). Because the starch dissolves easily, enzymes are conserved sufficiently at these low temperatures so that adequate fermentability can result over say 60 minutes.
  • The ideal malt for the Kurz /Hoch mashing method would thus be well-modified malt with also a high enzyme content. Does the Pale Malt from Southern Associated Maltsters fit this specification?

3. Mash dilute (3L/kg)

The often reputed advantages of thicker mashes are a lot of baloney. Enzymes might survive longer in thicker mashes but do less useful work – so what’s the point? Thinner mashes generally convert faster, have higher extract yield, and are less prone to darken. When mashing thinner cut back on sparge-water quantity to avoid over-extraction. Thicker mashes do cause more caramelization and Maillard reactions but is far less efficient than when the maltster creates it.

4. Mash in a single vessel of the correct design.

During infusion mashing it is the malt grist, mainly the husk material, which forms the filter bed at the bottom of the mashtun. At the start of the infusion mash this layer is separated from the false bottom of the mashtun by a liquid layer of dense extracted malt sugars. The floating of the filter bed depends on a suitable coarse crushing of the malt and partly on the presence of air bubbles on, and entrapped within the husks. In this case the mash is not stirred. Wort filtration thus takes place in the grain bed itself and not on the slotted false bottom of the tun. The mashtun configuration should be slightly wider than it is deep. The malt bed upon compaction at the end of runoff should not be deeper than 25cm. If it is deeper, efficient sparging will not be possible and the bed will “set” before enough of the good runnings can be extracted. Applying less dense sparge liquor also makes the bed less buoyant and so over time the mash sinks and the bed eventually compacts under any runoff regime. Skill is required to control the flow rate so that enough of the good worts are out of the bed before it collapses.

5. Mash at 5.3 pH.

pH affects the flavour of beer, its flavour stability and resistance to spoilage craft-organisms. Substances such as phosphates and products of protein breakdown in wort act as salts of weak acids at wort pH. Wort pH is often adjusted by addition of lactic acid but the pH change is relatively small because of the buffering effect. A salt of a strong acid and a strong base (like NaCl, the salt of hydrochloric acid) on the other hand provides no buffering action and adding the acid or the base changes the pH immediately. Buffering capacity is very important in brewing since it controls wort and beer pH. Overall, the optimum pH for enzymes that is active during mashing is pH 5.3 – 5.4. If the pH is higher than this, breakdown of proteins, starch and large dextrins is less efficient. This results in slower wort separation at the end of mashing, lower extract, lower soluble nitrogen and FAN concentrations and often lower fermentability. At higher pH values more polyphenolic material is extracted from the cereal husks with resulting astringency and unwanted increased colour. It is therefore good brewing practice to reduce water hardness by reducing the bicarbonate concentration of brewing liquor to less than 20mg /L (20ppm). One method is by adding phosphoric acid to the hot liquor tank and overnight heating to above 90°C. The mashtun pH is then further reduced to 5.3 – 5.4 by adding calcium sulphate and or lactic acid to the mash. The pH at the end of boiling also to a large extent determines the pH of the final beer. In general the pH decreases by about 1 pH unit during fermentation. 5.2 pH pitching wort thus usually gives a beer with a pH of about 4.2.

6. Use a single step rest only if your malt allows it.

Start sparging immediately with 76°C water which will aid in increasing the bed temperature – no mashout is done.

7. Add an antioxidant.

It is now realized that oxidation during mashing has several unwanted effects. Wort gets stale. Proteins containing free-Sulphur Hydrogen groups are oxidized and sulphur-sulphur bonds then formed between them can cause these proteins to form a coating on starch and malt endosperm cell wall fragments. As a result proteolysis, amylolysis and Beta-glucan breakdown are partially inhibited, causing a decrease in the amount of soluble extract obtained, and slows down mash separation. Oxidation of the mash also results in the oxidation of polyphenols. This causes increased colour and astringent bitterness. Even worse, lipid oxidizing enzymes oxidize unsaturated fatty acids and form products that accelerate stale flavours in the finished beer. When using dry milling and dumping malt in through the top of the mashtun air is trapped in the husks again increasing oxidizing potential. Our tiny mashtuns have loads of surface area with air exposure per volume, compared to enclosed mashtuns and bottom filling of big brewers. Good quality sweet wort has a fresh flavour and sparkling quality. This freshness is greatly diminished with long mashing times. Wort tastes dull and bland after a few hours and is irreversible damaged due to oxidation processes. The impact on the final beer is a lack of certain positive flavours – less maltiness, greater astringency and overall dull flavour. Other severe forms of staling (cardboard, aldehyde) may result. Fortunately all this is preventable with the simple technique of adding 20-30 ppm KMS to the mash. There is even now a special kind of anti-oxidant malt that is produced in Europe.

8. Crush coarse gelatinize well.

The Kurz / Hoch regime advocates a gentle vorlauf of 5-10minutes after the 20minute stand until runnings are clear and then runoff. One primary objective of milling is to leave the malt husk as intact as possible. An intact husk, including absence of shredded husks, helps wort separation in lautering and may reduce extraction of tannins, beta-glucans, silica and other undesirable components. Crushing finer will produce a smaller particle which more easily yield extract and probably yield higher extract, but comes with the risk of a stuck mash. Larger particles (from coarser crush) allow faster wort separation but come with the risk of extract loss. Mashtuns, with their deep grain beds, require coarse milling of malt. Coarser crushes will also allow ease of “mashing in” because it does not tend to form clumps and clots like finely crushed malt.

9. Sparge with 76°C water and pH of sparewater 5.5.

Higher temperature and pH during sparging increase polyphenolic material extraction with resulting astringency.

10. Stop runoff at 1010 and 5.5 pH

Extract recovered at the end of sparging is not simply diluted (quality) first wort. Last runnings contain little of interest to brewers making quality beer. Although large breweries have financial interest in collecting last worts as low as 1.003, craft brewers rarely collect below 1010.

11. Buy your Maillard compounds don’t try to mash them!

Many homebrewers have some fantasy image of immense malty flavours emanating from a decoction, but the reality is that decoction imparts only a subtle flavour difference. A no sparge will outdo a decoction every time! Adding a little additional münich, vienna or melanoidin malt will do the same.

12. Use quality malt!

The role of quality base and specialty malt in recipe formulation is going to become far more crucial in times to come. If your malt is likely to throw a haze use nitrogen dilutant or mash in at 58°C for a touch of proteolysis (15 minutes) then step up to 68/70°C. The most obvious time to degrade protein is during malting, when a full complement of proteases and peptidases are present. The vast bulk of amino acids are thus formed in malting, not mashing. In the malting of well-modified malt, more than 40% of the protein is broken down to soluble components. The “protein rest” in mashing is thus probably a misnomer because extensive proteolysis is unlikely in mashing due to the many protease enzymes that are inactivated during the kilning and the short duration of the low temperature stand. Solubility characteristics commonly define barley proteins. The less easily dissolved proteins dominate in high-protein barley. The ratio of the total soluble nitrogen (TSN) to total malt nitrogen (TN) is expressed on malt spec sheets as the Kolbach index. Too high and you’ve got problems associated with too much proteins in the beer like chill haze. Too low and there is no foam on the beer. Two row barley malt has lower nitrogen and protein content and also lower husk content. Six row barley malt has a higher nitrogen and protein content (is less modified) and a higher husk content. It has a higher diastatic power (more enzymes) so it is the malt of choice when large amounts of cereal adjuncts like maize grits are used (in double mashes). The extra husk aids in providing a lautering filterbed.

Making Sense of FAN (free amino nitrogen)

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Making Sense of FAN (free amino nitrogen)

By Moritz Kallmeyer
Chief Brewer Drayman’s Craftbrewery, Silverton Pretoria, June 2004

For yeast cell multiplication the yeast requires a source of nitrogen to form amino acids and nucleotides so that proteins, nucleic acids and co-enzymes can be formed. Yeast can remove the amino group from any one amino acid and use it to form other amino acids, from there the term “free” amino nitrogen. It is thus not necessary to provide a balanced mixture of amino acids corresponding to the mixture present in the yeast’s proteins. Instead a certain total amount of FAN must be provided to supply the N atoms needed by the yeast to synthesize amino acids which in turn is used to form proteins. The higher the amount of FAN in the wort the more fusel oil (higher alcohols & esters) is produced. It is thus desirable to regulate FAN levels by taking into account changes in grist composition and seasonal variations of raw materials, to control yeast growth. To prevent fusel oil formation in high gravity brewing about 25% of the malt is replaced with a carbohydrate adjunct which does not provide the excess amino acids and so the yeast does not form such high concentrations of higher alcohols. The yeast needs about 100mg of FAN per liter in the case of worts made with adjuncts and 200mg/L for all malt worts, to successfully ferment the wort.

The vast bulk of wort amino acids are pre-formed in the malt during malting. In the Kurz/ Hoch mashing system which is more dilute, less than10% of the amino acids formed in wort arise during mashing which is good. Thick, all-malt mashes with extended low temperature stands would increase amino acid formation by as much as 50% because soluble protein is available for attack by peptidases enzyme. This could negatively influence yeast performance (rate of growth, rate of fermentation and spectrum of flavour compounds produced). Furthermore if excessive amounts of amino acids survive into the final beer they could foster the growth of spoilage organisms in unpasteurized products.

Yeast Slurry pH as an indicator of yeast Autolysis

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Yeast Slurry pH as an indicator of yeast Autolysis

By Moritz Kallmeyer
Chief Brewer Drayman’s Craftbrewery, Silverton Pretoria, January 2004

At the end of fermentation, beer pH is usually between 4.1 and 4.40. An increase in stored yeast slurry pH above this end of ferment beer pH is a good indicator of yeast autolysis. Protease’s and other low molecular weight compounds of an acidic nature are also released which causes an initial sharp drop in pH during the first 24 hours of storage at 4°C. However, when a slurry is monitored right from the end of harvest through to re-pitching, there is a gradual increase in pH – especially from day three onwards.

Other compounds in the stored slurry that impacts negatively on subsequent fermentations are:

  1. An increase in FAN (free amino nitrogen) especially from day three onwards;
  2. A decrease in the stored glycogen *content (time and temperature dependant);
  3. An increase in the trehalose *content which is indicative of a response to increasing stress.

The authors concluded that the measurement of slurry pH is a simple, quick and inexpensive method to determine the quality of yeast slurry. The use of slurries showing high pH values impacts negatively on beer foam and beer flavour of the beer produced.

  • Trehalose (a non-reducing disaccharide / carbohydrate) is primarily a stress protectant at the cell membrane for organisms like yeast because it pocesses the ability to act like water (particularly during dehydration) as a water replacement.
  • Yeast will accumulate trehalose earlier during its growth when the major sugar in the wort is maltose
  • It appears to play an energy reserve roll (as a storage carbohydrate) in cell sporulation.
  • In brewing the stress of high gravity, osmotic stress, high temperatures, low levels of water activity and ethanol toxicity all induce synthesis of trehalose.
  • Threhalose is normally accumulated later in the growth of yeast than glycogen, at the decelerating phase.
  • Normal percentages in a cell is 1-2% of the dry weight, 5-10% is a little uncomfortable but higher than 10% is unacceptable except in dry yeast as this is essential in allowing the dehydration to occur successfully.
  • Some reports say that a high trehalose concentration in yeast at pitching improves viability, enhance the carbohydrate utilization rate and increase the production of higher alcohols such as isoamyl and isobutanol.
  • Glycogen is a storage carbohydrate essential in the lag phase for sterol synthesis, which is essential for good brewing yeast and thus a healthy fermentation.
  • Glycogen is accumulated in yeast early, while the glucose / sugar content is still high – it levels off as the yeast enters the stationary phase.
  • Glycogen degradation is accelerated when yeast is exposed to air during yeast handling or disturbed excessively between brews – with resulting poor yeast performance.

The Do’s and Don’ts of Yeast Handling

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The Do’s and Don’ts of Yeast Handling
By Moritz Kallmeyer
Chief Brewer Drayman’s Craftbrewery, Silverton, Pretoria, November 2003

The aim of this article is to discuss improved methods of yeast handling in a brewery to ensure good yeast health and optimum fermentation performance.

Introduction

The reality in most craftbreweries is that brewers don’t handle their yeast correctly ultimately impacting negatively on beer flavour. Conventional methods by old timers rarely involved much more than collecting yeast from a previous batch and unceremoniously dumping it into a new batch.

Yeast Handling

  1. The first step in ensuring that the next batch of yeast collected will be of good health is: daily trub removal from the fermentation vessel (FV).
  2. As soon as the yeast has dropped out of suspension (before chillback) The yeast must be warm cropped. Early warm cropping has significant benefits on yeast vitality.
  3. Yeast to be stored must be chilled down immediately to 0-2ºC. The thin early crop contains enough beer that will form a hydrative layer on top of the yeast in the storage vessel. No CO² pressure build up is allowed – due to the risk of CO² poisoning.
  4. Collected yeast should not be cold stored (before repitching) for longer than three days(optimum) or seven days (worst case scenario)
  5. Removing a batch of yeast from cold storage , critical inspection of the yeast, and timely acid washing of the yeast are some of the first routines on a brewing day. Principals of acid washing includes beer layer removal, dilution with sterile acidified water, pH lowering to 2.1-2.2; straining to remove protein trub; sedimentation to remove dead cells and regular uniform mixing.
  6. After a period of settling (+/- 3 hours) the excess acid water forming a layer on top of the yeast is removed and the yeast roused with fresh sterile wort from the kettle (5% of yeast volume) and sterile cold water.
  7. After rousing, the yeast is allowed to gradually atemperate to close to pitching temperature to avoid any temperature shock.
  8. One of the guiding principles in yeast handling prior to pitching is the adequate mixing of yeast until a uniform, decarbonated suspension has developed.

Summary

The key words in yeast handling are keep it cold (KIC), keep it short (KIS), keep it simple (KIS)

Tasting of Beer

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Tasting of Beer
By Moritz Kallmeyer
Chief Brewer of Drayman’s Craftbrewery, Silverton Pretoria, March 2003

Introduction:

After an exercise session your brain secretes endorphins – a powerful hormone like chemical that leaves you with a sense of euphoria / well being. So powerful is our sense of taste and smell that it can in an instance transport you back 20 years to a place and detailed atmosphere where you previously tasted or smelled something. It can also trigger endorphin secretion. Smelling a freshly poured pint can make your mouth water – the start of the digestive process – even before you take a sip! The opposite is also true – smelling something repulsive can be laid down in your memory permanently so that even after years have passed, if you smell something that reminds you of that smell it can trigger reverse peristalsis of the oesophagus!

The human senses are the ultimate instruments for beer evaluation, and surely will remain so. No machine can replace the baffling accuracy by which the human nose can recall intensities and types of aromas. It is thus crucial that you train your senses in identification and filing away for later recollection of smells and tastes of importance to beer and brewing. Taste and smell is big business today. Think of the billions of rand involved in the perfume industry. The ultimate enjoyment that you will experience every couple of hours for your whole life is the tasting of food and drink. Most of us involved in the brewing industry drink beer because we enjoy the taste and flavour – we don’t drink for effect per se – although it is a welcome fringe benefit! The motto: Flavour Sells! might not always be the truth. Lite beer was successfully launched all over the world using very creative advertising campaigns often linking it with sport stars. In this instance it is actually lack of flavour that sells. Without these strong marketing actions lite might normally be perceived as just flavourless, watered down beer. Thus; the blander the product the greater need for creative advertising to sell it.

Historical Preview

Here are some of perhaps the first written records we have that our ancestors’ evaluated beer and associated the taste with something else. When the Romans invaded England in the year 100 A.D. they brought with them big supplies of wine – but soon their supplies ran out and they began to consume and brew what was then viewed as a thoroughly uncivilized drink. The Emperor Julian wrote that “this wine made from barley smell of goat”.

Thomas Becket, who later became the Archbishop of Canterbury, went on a diplomatic mission to France in the year 1158. He took with him 2 chariot loads of ale, brewed from choice fat grain – as a gift to the French who wondered at such inventions! “A drink most wholesome, clear of all dregs, rivalling wine in colour and surpassing it in flavour!

Do’s and Don’ts of Beer tasting for evaluation purposes

  1. The best time to taste beer is in the morning when your senses are the sharpest.
  2. You have to be stone cold sober because alcohol numbs the senses.
  3. You should be slightly hungry, then your appetite is at its peak. Your senses will be in a state of anticipation of the tasting experience. When you think of a tasty pint your mouth waters!
  4. Strong toothpaste and smoking numbs the palate – avoid for at least two hours.
  5. Spicy foods like garlic, cloves, onions and chillies: all a no-no for 12 hours before the tasting.
  6. Use a tongue scraper regularly to remove old mucus build-up on the taste buds that will impair taste sensitivity.
  7. Don’t wear strong aftershave lotion or perfume.
  8. Do taste away from main smell areas of the brewery. The olfactive sense is quickly saturated with aromas present. A quiet, well lit, neutral area is ideal.
  9. Chew a piece of plain white bread and rinse the mouth with clean cool water between beers to clean the palate.
  10. The beers should be poured, evaluated and scored one at a time.
  11. Use blind tasting whenever possible. They say a glance at the label is worth a 100 years of tasting experience. You get closer to the truth with blind tasting.
  12. Taste beers in order of lightest to heaviest so that what has gone before does not overwhelm that which is to come.
  13. Taste in trade as often as possible – ask the regular drinkers an opinion.
  14. Taste wort, green beer and beer at every stage of production to form a library of tastes and aromas for fault identification.
  15. Practise, practise, practise!

Actions During Beer Evaluatio

1. Aroma

    The aroma is the best assessed when the beer is freshly poured from the bottle into the tasting glass. You should get your impressions down immediately. You can close the glass with your hand; give it a swirl, then give one good strong sniff, inhale deeply.

2.Appearance

    Now you can hold the glass up against strong light and evaluate appearance (clarity) and colour at leisure.

3.Tasting

    Tasting comes last because it is the best and most important part of the evaluation. Slowly take one small sample in your mouth, roll around and swallow. Base your impressions on this. If you want to refresh your memory on the beer let time pass and refresh your taste buds with water.

4.Mouth aroma

    Beer aroma shows itself twice, once when you take a sniff (nose aroma) and secondly when the beer is entrapped in the mouth and the aromatics pass to the olfactive zone via the anterior nasal passage. Accentuated mouth aroma can be practised by slurping beer from a large tablespoon into the mouth.

5.Overall Balance

    Balance is probably the most fundamental characteristic of any beer. The expected balance differs from style to style and it is crucial that a reputable taster correctly interprets the required balance for each style of beer. You always taste bitter and sweet together in different proportions according to the brewer’s interpretation of style or unique design.
    6. When the formal evaluation is over and you’ve scored the beers, forget all the technical ramble and just enjoy what’s on offer for what it is.

 

Brewery Bacterial Contaminants

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Brewery Bacterial Contaminants
By Moritz Kallmeyer
Chief Brewer of Drayman’s Craftbrewery, Silverton Pretoria, January 2004

Bacterial cells are the oldest inhabitants of planet earth. Rocks which were found by geologists in the Baberton area, timedated to be 380 million years old, showed the familiar rod shaped bacterial cells clearly when examined under a craftscope. Bacterial cells were here first and the fact that they still thrive today is evidence of their incredible ability to adapt. Some are found in the ice on the poles, others in the hot geysers that spew 100°C water, where nothing seemingly can survive.

French scientist Louis Pasteur is the father of modern brewing. His work on yeast allowed brewers to understand, for the first time, exactly what happened during fermentation. Previously beer frequently went off and became undrinkable and the brewers had no idea why. Most brewing companies in those days (and some home-brewers nowadays!) expected losses of 20% or more through waste and regularly had to destroy whole batches of sour beer.

The old saying that cleanliness is next to Godliness is especially applicable in the running of a brewery. Some brewers have dubbed themselves as glorified janitors! The brewer himself, with the degree of craftbiological control he practices during the entire process, controls the nature and magnitude of bacterial contamination in a brewery fermentation. It is a small consolation for a brewer to know that the number of bacterial genera that could survive in a brewing process are relatively small. Then again, brewing processes, as practiced by some brewers seriously lack sufficient craftbiological checks. Several factors account for the limited growth of bacteria during a brewery fermentation. Such spoilage organisms may be sensitive to hop resins (the higher the hop rate, the lower the risk of bacterial contamination), a high ethanol concentration, low pH, lack of oxygen during most of the process, limited sugar after fermentation, early heating steps and low temperature maintained during fermentation and processing.

Just on a pronunciation note. It doesn’t matter if the word is written in its original Latin form in italic or not. All “c’s” and “ k’s” for that matter are pronounced as “k’s”. Lactobacillus Bacteria (pronounced Lak-to-ba-kil-lus Bak-te-ria), craftcococcus (pronounced Mikrokokkus) Acetobacter (pronounced Aketobakter). Nowadays in normal writing the bacteria name is usually not written in italic and the pronunciation thereof, by the uninformed, has been concocted into a mix of c’s (as in sea) and k’s (as in cookie). Hopefully after studying this article you will be able to name and correctly pronounce the specific bacterial contaminant in someone’s beer at the next meeting!

In order to identify different bacteria under a craftscope, various dyes are used like methylene blue. There are some procedures (like differential staining) that use more than one stain in order to distinguish differences in the chemical composition of the bacterial cell. One of the most important differential staining techniques is the Gram stain or gram-reaction. Gram –positive bacteria that are of significance to brewing include the members of the lactic acid bacteria especially the genera Lactobacillus and Pediococcus. The important gram-negative bacteria family that have been responsible for beer spoilage are Acetic acid bacteria, Zymomonas, and a few members of the family Enterobacteriacea, Pectinatus cerevisiiphilus and Megasphaera. Certain endospore- forming bacteria belonging to the genus Bacillus and certain craftcoccus species (craftcoccus kristinae) have, on occasion caused problems in breweries.

Gram-Positive Bacteria

Lactobacillus
These are catalase-negative, nonsporulating, rod-shaped organisms that are either homofermentative or heterofermentative, based on temperature tolerance and the mode of fermentation. There are several species of lactobacilli isolated from beer, and these constitute the predominant spoilage organisms in the beer industry. They are resistant to hop bittering compounds , and some of these lactobacilli have been implicated in the production of diacetyl that is responsible for the “buttery” flavour. Although all lactobacilli produce lactic acid, the level of the acid accumulated does not reach the high threshold levels needed to make a significant flavour impact on the final beer. However, the spoilage can be observed as “silky” turbidity.

Pediococcus
These are catalase-negative , homofermentative cocci that form characteristic pairs or tetrads due to their cell division in two planes. Pediococcus damnosus is the most common spoilage organism of the genus found in breweries that produce lager beer. The organisms are seldom found in the pitching yeast, but are found at times during the late fermentation or in the final beer. The spoilage by pediococci is somewhat similar to that caused by lactobacilli. Pediococci are responsible for the sarcina sickness and give rise to high acidity and buttery aroma due to the production of diacetyl.

Other Gram-positive craftorganisms
Several gram-positive craftorganisms, although less important as spoilage organisms, have been detected in brewery fermentations. Although heterofermentative cocci like Leuconostoc mesenteroides have been detected in breweries, they are not known to produce any beer spoilage. On the contrary, Streptococcus lactis and craftcoccus kristinae, which are relatively acid-tolerant and hop-resistant, have been responsible for beer spoilage. Likewise, thermophillic endospore-forming bacilli like B.coagulans and B. searothermophilus have been isolated from breweries. These organisms are known to produce high levels of lactic acid when sweet wort is left for an extended period of time at elevated temperatures.

Gram-Negative Bacteria

Acetic Acid Bacteria
These are gram-negative, rod shaped bacteria capable of producing acetic acid from ethanol. Acetobacter and Gluconnobacter are two important genera under the group acetic acid bacteria that are traditionally associated with brewery fermentations. Acetobacter is known to oxidize ethanol to CO² and water via the hexose monophosphate pathway and TCA cycle. In the case of Gluconobacter, the hexose monophosphate shunt constitutes the most important route for sugar metabolism. The entire glycolytic and TCA cycles are not functional in gluconobacter. Beer is not expected to contain oxygen in the final form, and these organisms cannot thrive in beer under highly anaerobic conditions. Problems with Acetobacter and Gluconobacter can only be seen in beers that have low oxygen tension due to process defects.

Obesumbacterium proteus
The best- known brewery contaminant in the family Enterobacteriaceae is Obesumbacterium proteus. I have a strong suspicion that most homebrewers have encountered this bacterium some or other time. It is a gram-negative, nonacid-fast straight rod that can be found multiplying in the pitching yeast. It can grow in unhopped wort and is able to tolerate pH values ranging from 4.4 to 9.0. This organism is known to suppress the fermentation process and is also responsible for the increased level of dimethyl sulfide, dimethyl disulfide, diacetyl and fusel oils. Beer contaminated with Obesumbacterium proteus has a characteristic parsnip-like or fruity ordour.

Zymomonas
These are gram-negative rods that occur mostly as single cells, in pairs, chains, or filaments, and most strains are non-motile. Motile strains have one to four flagella. Zymomonas mobilis is the most common brewery contaminant, and its most distinctive characteristic is the ability to convert glucose or fructose to ethanol and CO² via the Entner-Doudoroff pathway. Its growth is only inhibited by around 8% ethanol. It can also be completely killed by a few minutes exposure to 60°C. Zymomonas mobilis is known to produce unacceptable levels of acetaldehyde and hydrogen sulfide in lager beer.

Other Gram-Negative craftorganisms
Several other less important gram-negative organisms have been reported in brewery fermentations. One such gram-negative contaminant is Pectinatus cervisiiphilus, which is known to produce acetic acid, propionic acid, acetoin and hydrogen sulphide, either in fermenting wort or packaged beer. Beers contaminated with this organism are generally turbid and have a rotten egg odour. The other organism of minor significance is the gram-negative coccus, Megasphaera, which imparts cloudiness and an unpleasant puke-like odour to the beer. These characteristics are primarily due to the production of butyric acid during fermentation.

What is important to remember here for us brewers is that even a bacteria described as of “minor significance” by some white-coat researcher can be emotionally devastating for a brewer trying in vain solve the mystery of his butyric smelling witbier!

References:

1. Reed, G., Nagodawithana T.W.,1991. Yeast Technology 2nd edition , p.124-126.

A few beer faults and their origin – in a nutshell

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A Few Beer Faults and Their Origin – in a nutshell
By Moritz Kallmeyer
Chief Brewer Drayman’s Craftbrewery, Silverton Pretoria, January 2003

Roughness:
Abnormal water composition, insufficient boil, excess tannin, excessive or alkaline sparging, insufficient kettle evaporation, hot-side aeration.

Fruity aroma /flavour:
From esters, higher alcohols, acetates of higher alcohols. The consequence of under oxygenation of the pitching yeast, too high fermentation temperature, too low pitching rate, or a deteriorated yeast strain. When unpleasant estery and combined with vegetal aroma and flavour it is from coliform contamination of the wort or yeast culture.

Celery odour:
Hafnia protea contamination, probably from tainted yeast culture.

Bitter-vegetable taste:
From deteriorated hops (oxidized beta-acids)

Buttery (diacetyl) flavour:
Where it is strong and like rancid butter, from lactic-acid bacteria – significantly Pediococcus. Slight or pleasant diacetyl flavour more often from low pitching rate, under oxygenation, petite mutants in culture yeast, or characteristic of specific yeast strain. Also from beer racked off its primary sediment too early or oxidized in the secondary.

Cardboard Taste:
Oxidation from too much air in the bottle headspace; trub carried into / lipids oxidized in the ferment; warm storage mishandling; insufficient boil; when with poor head retention, from lipids in the beer.

Sulfury aroma and flavour:
Too low on fermentation temperature; poor rinsing of sulphur-based sterilant; from wild yeast, Zymomonas or coliform bacteria. May be yeast strain specific, or from autolization of sedimented yeast. Except when from bacterial contamination, may be reduced by aging or by scrubbing with carbon dioxide.

Tinned sweetcorn ( Big Corn Bites) aroma and flavour:
Is characteristic of dimethyl sulphide (dms), from poorly malted barley especially sixrow; high moisture malt; hot wort not chilled quickly enough; coliform bacteria contamination.

Sour taste:
From too low Ph (too much acid added); from lactic or acetic acid bacterial contamination.

Medicinal aroma / flavour (Phenolic):
From wild yeast or bacteria; chlorine in the ferment either from water source or improper rinsing of chlorine sterilant; plastic leaching contamination; excess of phenolic material from over sparging or weak wort boil. Accentuated by high fermentation temperatures.

Astringency:
Excessive sparging, hot-side aeration; yeast autolization, excessive or oxidized trub carried over into the ferment.

Disagreeable smell / taste; turbidity, acidity:
Pediococcus or Bacillus contamination of the primary ferment.

Green apple flavour:
From acetaldehyde, the principal volatile acid in beer. From too high a fermentation temperature; yeast strain characteristics; bacterial contamination from the ester Ethyl hexanoate.

Banana aroma / flavour:
Acetates. Yeasts strain characteristics; wild yeast contamination; too high fermentation temperature.

Thinness:
Wort extract too low; excessive mash protein digestion; dextrin-poor extract, from too low conversion temperature.

Haze:
Poor mash digestion; Insufficient boil; wild yeast; bacteria; oxidation of beer; poor starch conversion in mash.

Gelatinous precipitate:
Excessive sparging; poorly degraded hemicellulose.

Lack of head:
Excessive protein rest; over modified malt; too high on adjunct ratio; lipids in the ferment (excessive sparging or autolized yeast) over-foaming in the ferment, repeated foaming due to rough beer transfers; over-boiling; insufficient or deteriorated hops; contact with oil.

Gushing:
Excess of priming sugars; beer not fermented out before packaging; temperature fluctuation; mishandling; old infected malt; iron in water; wild yeast contamination.

Skunky odour:
Beer light-struck. Avoid direct sunlight during brewing and in package; reduce headspace.

Rotten egg odour:
Hydrogen sulphide; yeast strain characteristics; fermentation by wild yeast; weak fermentation; in bottled or kegged beer it may be from contamination by Zymomonas bacteria.

13 Health Reasons To Drink Beer

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13 Health Reasons To Drink Beer
By Moritz Kallmeyer
Chief Brewer of Drayman’s Craftbrewery, Silverton Pretoria, February 2003

Introduction

Medical studies have over the years consistently demonstrated that moderate consumption of beer can be part of a healthy lifestyle.

  1. Drinking beer is good for your liver!
  2. Drinkers of beer can get rid of poisonous heavy metals like lead and copper up to five times more effectively than tee-totalers. Alcohol causes the small blood vessels in the liver to expand which speeds up metabolism. (Beer Net Publication, April 2001 Biological Institute, University of Charkov, Prof. Anatolij Bohkov)

2. It lowers your risk of heart attacks.

    Those drinking beer on a daily basis, averaging 4-9 litres of beer per week, have the lowest rate of heart attacks. Their risk is approximately 50% lower when compared to non-drinkers. (Bobak et al 2000; Hoffmeister et al 1999; Kitamura et al 1998).

3. It prevents cholesterol from oxidizing.

    Hop compounds xanthohumol and quercetin, both strong antioxidants are very effective in their ability to prevent LDL (the bad form of cholesterol) from oxidation. When LDL is oxidised it will be laid down on the artery wall causing them to narrow, thus increasing the chances of blockage and heart attacks (Miranda et al 2000). Antioxidants are thought to be able to quench and inactivate the free radicals, which may cause the types of cellular damage that can lead to both cardiovascular disease (CVD) and cancer.

4. It boosts your antioxidant levels.

    Recent studies have turned its attention to the anti-oxidative role of plant polyphenols in general, their beneficial influence on various aspects of health and in particular, their role in dealing with dangerous free radicals within the body. Analysis can show how much of these good compounds are in beer- but can it be absorbed (called bioavailability) by humans and hence have a positive effect on health? Yes! The malt-derived antioxidant ferulic acid is 100% absorbed by humans (compared to 11-25% absorption of ferulic acid from a tomato). The total level of antioxidants in the blood increased significantly after just a single glass of ale, again proving that antioxidants in beer are well absorbed (Ghiselli et al 2000) Not that any person in his right mind would settle for just a single glass!
      5.

5.It boosts vitamin B6; B12; folate and mineral levels.

    If compared to wine and spirits, beer is the only beverage that contains significant levels of vitamins. High homocysteine (Hcy) levels in the blood are associated with increased risk of CVD. Vitamins like B6; B12 and especially folate (all naturally occurring in beer) are now recommended as part of doctors orders to be taken daily to control elevated levels of Hcy (Walker, BRI, 2001). The minerals in beer come from both the malt and the brewing liquor. The beneficial ratio of potassium to sodium is particularly important in relation to cardiovascular disease.

6. Keeps homocysteine (Hcy) levels low.

    Van der Gaag and his colleagues found that drinking wine and spirits increased serum Hcy levels, where as, counteracted by folates and vitamin B6, beer consumption had no influence. A clear case of beer should be first for thirst!

7. Drinking beer boosts your soluble fibre intake and lowers cholesterol.

    One of the most effective forms of soluble fibre for lowering cholesterol is betaglucan, which is the predominant form of fibre in beer. Beers with high malt content like craft beers may provide up to 30% of the recommended daily fibre intake (Gromes et al 2000).

8. Drinking beer help in combating cancer, cardiovascular disease (CVD) and other immune system attacking diseases.

    Hops contain compounds that are unique and rare in nature –like prenyl flavonoids (8PN) which are phytoestrogens that are natural plant based compounds, which mimics the natural oestrogens in the body (Bingham et al 1998). The highest 8PN levels in beers have been found in dark and bitter ales and stouts and from craft breweries where whole hopping is practised.

9. Beer ensures healthy bones.

    Beer has a nutritional benefit that promotes healthy bones and connective tissue (Dr Jonathan Powell, Kings College, London). Because of the brewing process, silicon is leached from barley grain in a form that is readily accessible to the body.

10. Beer protects against gallstones.

    Prof. Oliver James, from the school of clinical medical studies at the University of Newcastle upon Tyne, says that beer protect against gallstones, kidney stones and the bacterium Heliobacter pylori, which is directly linked to stomach ulcers and cancer.

11. Hoppy beer protects against cataracts.

    Certain hop flavonoids, in particular xanthohumol and its isomerised form isoxanthohumol, can show positive effects against heart disease, Alzheimer’s disease, osteoporosis, cataracts and certain forms of cancer.

12. Beer promotes sleep.

    A famous vitaminologist Professor Steep from Germany prescribes beer (not drugs) for insomnia. Two vitamins, lactoflavin and nicotinic acid that are present in beer are the secret weapons that promote sleep. The same two vitamins also speed up bone degeneration after a fracture and prevent low blood counts. Hops in beer itself is a natural sedative that also promotes sleep.

13. Beer reduces risk of thrombosis

    The flavonoids that are present in roasted malt, also to a lesser extent in hops and barley, prevent blood platelets from clamping together –making the blood less sticky – therefore decreasing your risk of blood clotting that can cause heart attacks or thrombosis.

 

The Role of Polyphenols in Beer Haze Formation

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The Role of Polyphenols in Beer Haze Formation
By Moritz Kallmeyer
Chief Brewer Drayman’s Craftbrewery, Silverton Pretoria, February 2003

Abstract:

Phenolic compounds are present in all vegetable foods. Polyphenols are extracts of various plants which have the ability to react with protein in animal skins to produce leather. Tannins are polyphenols and nowadays the term tannin has come to describe all polyphenols in a plant extract regardless of their ability to tan leather. Beer has a complex mixture of phenolic compounds from 150mg/L to 330mg/L in concentration. The majority (about 2/3) are malt derived especially from the husk material of the malt. The remainder (about 1/3) comes from the hops extracted during the copper boil.

Polyphenol –are they essential?

to their specific properties, brewers find polyphenols interesting technologically (foam maintenance, physical and chemical stability and shelf life). Health researchers find them interesting because phenolic compounds can act as antioxidants in the human body, for example as protective agents against the oxidation of ascorbic acid and unsaturated fatty acids. Studies proved that the intake of beer significantly increased plasma antioxidant capacity. Today we know that polyphenols are important molecules in brewing. Positively speaking they have the ability to react with proteins during wort boiling to form the hot break; during cooling to form the cold break; during post fermentation when they are involved in the formation of chill haze and permanent hazes – which can then be removed by filtration. Negatively speaking they have the ability to react with proteins to form haze in the final pakage after a period of time (expiry date). Beer remains an unstable product.

Simplistically, polyphenol is one of the two chemical entities which control the colloidal stability of beer, the other being proteins. Proteins are derived from malt and are extracted from the malt during the mashing process. The fate of proteins is subsequently controlled by other brewing processes (not the scope of this article). The generation of beer haze is due to the extremely complex bio-chemical interaction between these two entities.The majority of modern treatments used to improve the final beer stability are aimed at the removal of either half of the protein fraction, or half of the polyphenol fraction. In some breweries both fractions are treated.

Polyphenols may be conveniently divided into three classes:

  1. Simple (phe)nols which are derivations of hydroxyl benzoic or cinnamic acid (mostly from malt);
  2. (Flavo)nols with more complex structures (mostly from hops);
  3. Proanthocyanidins, anthocyanogens, catechins and leucoanthocyanins (arises equally from malt and hops).

All of the above single molecules of the various compounds are the building blocks of larger molecules, the polyphenols. The single units are referred to as monomers. Two monomers, which not necessarily are identical, can join to form a dimer. A dimer plus a monomer form a trimer and so on.

Various studies have shown that monomeric phenols have little effect on haze formation but that dimers and trimers strongly accentuate haze formation. Polyphenols on their own contribute little to haze formation. Haze is composed fundamentally of complexes between condensed polyphenols and proteins.

In hot water extraction of hops such as occurs when making a hop tea for dry hopping also leads to the extraction of polyphenols into the hot water. This can have an adverse effect on colloidal stability. When dry hopping with whole hops or hop pellets, this does not occur.

Oxidizable Polyphenols:

Amongst the larger condensed phenols it is not only polyphenols that are problematic, but oxidizable phenols. There are not many of these oxidizable phenols in hops. It is mainly a malt problem. The simpler phenolic molecules are more polar, i.e. their relatively simple structure has more pronounced spots of unbalanced charges, and they are thus electrically dipolar. Without going into detail, polar molecules are very soluble and in fact, the vast majority of all phenolic compounds are extracted with the first runnings! Over time simple phenols will complex into polyphenols under acid conditions and oxidise and complex with protein into haze. However, good beer doesn’t last long enough for this to happen! The real problem with haze and astringency is the existing small fraction of less polar, i.e. more complex and large polyphenols. Many fingers have been pointed at Catechines (flavan-3-ols) and Anthocyanogens (flavan-3,4 diols), and especially their polymers, in the formation of haze.

As you would have gathered by now, polyphenols are not so soluble and when they are dissolved by higher Ph water (>5.5), they are repulsed by the polar medium that they are in. They thus tend to floc together (hydrophobic force) and with catalysts like metal ions and oxygen, complex with other large (and less soluble) molecules fairly quickly. This is the unsightly but essentially tasteless so called “tannin-protein haze” (it actually contains many other components of the wort). The protein neutralizes the tanning power of tannoids by forming essentially “tanned” bonds. Tannoids, on their own, have a definite dry astringent taste!

The oxidized polyphenols with tanning power (MWt 700-1000) are called “tannoids” (or tannigens) and they try to turn your tastebuds into leather. They do this by covalently cross linking proteins in your tastebuds just as they do in tanning leather and in forming haze. They were not actually intended to do this, they seem to be located in the husk fraction of malt mainly as an astringent inhibitor against fungal and bacterial attack on barley corn. Nowadays certain sorghum grain varieties are bred with high astringency as a “put off” to birds.

The oxidized polyphenols in sweet wort will “readily complex out” as hot break. Despite their size, they are a first and middle runnings extraction problem. These are best controlled by recycling wort through the grain bed, or vigorous boiling to form hot break during the boil phase.

The unoxidized, oxidizable polyphenols are less soluble and typically a late runnings problem. A large portion can survive (uncomplexed and unprecipitated) into the hopped wort, waiting for oxygen so as to cause haze and astringency problems by becoming tannoids. These are best controlled by terminating the sparge early at SG 1.010, keeping sparge water pH<5.5, keeping sparge temperature below 75ºC (as measured at the strike point on top of the grain bed and not as a reading on the hot liquor tank gauge) and crushing your malt coarse.

Factors affecting haze formation from polyphenol extraction:

Barley variety:
Levels of anthocyanogens were found to be higher in 6-row barleys than in 2-row barleys. Beers from 2-row malts thus had better colloidal stability.

Malt modification:
Well modified malts of high proteolytic ability have a greater degree of solubilisation of tannins than less well modified malts. Well modified malts tend to form less chill hazes.

Polyphenol content:
A barley variety ANT-13 which was bred with low polyphenol levels resulted in a beer with higher colloidal stability.

Milling of Malt:
The “husk fraction” in brewing literature includes the true leafy husk and the bits of fused-on pericarp/testa & aleurone layer. Many of the problematic polyphenols in the true leafy husk of malt have been leached out during repeated steeping during malting. However there are also high concentrations of problematic polyphenols in the pericarp/ testa and aleurone layers. These are some of the least modified (enzymically broken down) parts of the malt kernel and contain the least extract. As least modified, they are more likely to remain as big bits in a coarse crush. The sparge process removes extract from between and from within the kibble of the grain bed. The osmotic leaching process of removing extract (of anything soluble) from within bits is slowed down if the bits are big. The solvent (water) simply has further to penetrate. If the big bits are the “husk fraction”, which is low in fermentable extract and high in oxidizable polyhenols, then a coarse crush is beneficial for reduced polyphenol extraction. If the big bits happen to be starchy endosperm bits, then advanced gelatinization of starch is beneficial for better extract of sugar.

Brewing Liquor:
CaCl2 and CaSO4 reduce the mash pH. Calcium will precipitate oxalate and proteins responsible for haze.

Mash pH:
Measure your mash pH from a hot sample taken from inside the mashtun about 10 minutes after mashing in. (Make sure your pH probe is accurate and can handle the temperature.) Aim for 5.3 to 5.4, no higher. Remember it is the pH of the mash that matters, not the pH of the water before it enters the mash! You can alter the mash pH by addition of lactic acid to the brewing water or straight into the mashtun.

Sparging:
Stop sparge when SG drops to 1008 to 1010 and pH drops to 5.5. or you run the risk of extracting tannins that will give your beer an astringent flavour and which will increase the risk of hazes.

Hops:
The higher the anthocyanogens content of hops, the higher the “haze risk index”

Good Rolling Boil:
Boil for at least 70 minutes. Don’t boil for more than 2 hours since you run the risk of the hot break re-dissolving.

Carragheenan:
Use Irish Moss for the last 30 minutes of the boil. Many home brewers omit it because they see no difference, in many cases the reason is that they use too little. I recommend 5g per 25L boiler volume.

Protein Rest:
For well modified malt some studies recommend a rest at 40°C for 20-30 minutes followed directly by a conversion rest. I personally have good results with a 55°C rest for 20 minutes.

Chill Quickly:
Home brewers should spend more money on their chiller design efficiency than on state of the art filtration systems. Maximum cold break formation is essential to improve beer quality and stability. Even standard ales should be heat-exchanged to 14°C.

Acknowlegements:

I am greatly indebted to the authors below who gave me a better understanding of polyphenols and their role in brewing. I have unashamedly copied whole paragraphs from their articles for this write-up – simply because I could not explain it better than they have had.

  1. Controlling Phenol Extraction, Charlie Scandrett, April 1997. Brisbane Australia.
  2. Advances in Beer Stabilization, Mike O’Neill, February 1996.
  3. Beer Hazes, Gillian Grafton, October 1995.
  4. Basic Brewing Science, Dr. Trevor Wainwright, January 1998.

Hangovers and “hanging overs”

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HANGOVERS AND “HANGING OVERS”

By Moritz Kallmeyer
Chief Brewer of Drayman’s Craftbrewery, Silverton Pretoria, March 2003

I think that the over 40 year old section of the population experience less hangovers than the rest. In my own case, it comes with the collective recollection of all previous over- drinking bouts and how terrible you can feel. Let’s face it; some situations just lend themselves to getting a hangover. The crowd with the Proheps, Curonsan C and essentiales in their bathroom cupboard is most probably the same (young inexperienced) crowd that the night before were drinking hard tack, alcohol spiked soda pop with “spinning your head” names or were trying out the whole shooter and cocktail menu at the same time. In my younger years as a beer drinker in the pubs (after experiencing to many hangovers) I started following the example of old timers in the trade. The art of “pacing yourself” with each beer is a difficult one to master- especially as a boisterous evening progresses – or nowadays if the beer I brewed was particularly flavourful.

There are more hangover “cures” than there are styles of beer. For instance, back in the Middle Ages one cure called for a mixture of bitter almonds and raw eel. Then there’s the suggestion that you mix together vinegar and raw eggs, and swig them down with a giant gulp.

If you can think about measures beforehand without spoiling your evening, then the precautionary glass of milk really is worthwhile or eating a light meal, high in fat like a sardine salad (with olive oil)an hour before going out. It will retard the absorption of alcohol, and protect your stomach against the worst consequent irritations.

If you do overindulge on the night out (and you are wise enough to be responsible) have the taxi drop you off at your home. You will soon figure out that it is worthless trying to go to bed (unless you don’t mind to spend the whole night holding on to the bedpost to prevent the ceiling from spinning!)

Incidentally… this is a good time to admit to yourself that you are drunk – and that it was a stupid idea! Now is the time to act and to call George! Englishmen of old used a goose-tail feather to induce what medical practitioners call reverse peristalses, but you can use anything you choose. The correct procedure before hanging over is to down a litre of water and repeat this process twice.

An irritated stomach may produce acid. That is why antacid patent medicine can be helpful. Sleep helps the body to recover. For the same reason a tired or unfit drinker is especially vulnerable to hangovers – and no two people respond in quite the same way to each different drink. A shower is refreshing, and cleanses the soul. Vitamin C helps the liver detoxify the blood, and B vitamins may be beneficial. Fructose helps the body metabolise alcohol. It also replaces blood sugar, which may be low in the morning. A low level of blood sugar makes you feel weak. Eat bread and honey or drink a pint of sweetish Mild Ale! Jewish remedy: To combat dehydration, upset stomach and hunger, drink chicken soup. Drink some more cold water (mineral water is alkaline as well as being quenching) before retiring to bed with an extra pillow to keep you more upright (this should stop the ceiling from spinning!)

Extra equipment needed for the night is a bucket for urinating in and a 2L jug of cold drinking water which you should finish before morning. On a precautionary note, please space these two items well apart next two your bed to avoid a mix-up during the night! Alcohol causes dehydration because it is a diuretic – it is thus absolutely crucial for quick recovery to hydrate your body continuously. In fact if you had followed the one pint beer one pint water rule you would never have suffered a hangover in the first place and in part would have walked yourself sober; back and forth to the loo!