Brewing Process Flashcards
Two row barley is native to which continent?
Europe
Six row barley kernels contain a greater proportion of husk which can impart what flavour to a finished beer?
Grainy or husky flavours.
Six row barley also has higher protein levels which can cause haze in finished beer.
Increased protein means there are more enzymes which can be useful for making adjunct beer.
Brewers often prefer two row barley because:
Plump kernels contribute more extract for a given weight of grain.
What are the three key stages of malting?
1) Steeping
2) Germination
3) Kilning
During steeping moisture content of the barley rises from about 12% to how high?
About 45%
Hydration stimulates biochemical reactions that start the growth of a new barley plant inside the kernel.
How long do maltsters keep barley moist during the germination phase?
3 - 5 days.
This allows the barley seed to start growing.
Why is germination critical in making malt?
It makes starch (a fermentable sugar) more available during brewing.
What does the term ‘modification’ mean when it refers to malting barley?
Modification refers to breaking down proteins into starch during germination.
Starch is a fermentable sugar. More available starch is good for fermentation.
Modified barley is also known as what?
Green Malt.
What are the 4 goals of kilning barley?
1) Reduce moisture to about 4%
2) Preserve enzymes so brewers can activate them during brewing
3) Drive off DMS and other undesirable flavours.
4) Develop malt flavour through light toasting of the grains.
What is the primary grain used to brew beer?
Malted Barley
What is malt made from?
Grains like barley and wheat.
What are the three parts of the barley kernel?
Husk, embryo and endosperm
What is the function of the barley husk?
Provides protection for the barley embryo.
What is the function of the barley embryo?
Contains the plant’s vital elements which begin to grow when the kernel sprouts.
What does the endosperm do?
Contains starch reserves to fuel the growth of the plant.
Are raw barley kernels hard or soft?
Rock hard.
What are the five types of base malt named in the book?
Pilsner Malt, Pale Ale Malt, Munich Malt, Vienna Malt and Wheat Malt
What are the two types of malts known as?
Base Malts, Specialty Malts
What does extract refer to?
The malt carbohydrates and proteins that can be dissolved into the wort during brewing are known as extract.
Just prior to fermentation the amount of extract is measured by an original gravity reading.
What is the Lovibond scale?
The Lovibond Scale is a measure of malt colour.
Pale malts may be as light as 1-10 degrees while black malts can be as highas 600 degrees.
What is Diastatic Power?
Barley enzymes are needed to convert starch into fermentable sugar. A malt with high diatstatic power will be more effective at producing fermentable extract.
What is the term for starch or sugar that does not come from malted grain?
Adjuncts
Adjuncts contribute ____________ to finished beer.
little to no flavor
Sugars and sugar rich substances consist entirely of fermentable extract, so contribute nothing but alcohol.
What is the scientific name for hops?
Humulus Lupulus
What type of plant is hops?
“bine”
Which hops plants are chosen to make beer?
Unpollinated female plants.
Male plants are usually destroyed.
What part of the hops plant is picked to be used in brewing?
The Cone
_______ is a yellow-gold powder that contains the compound that flavor beer.
Lupulin.
What are the two acid compounds that come from hops resin?
Alpha acid - “humulones”
Beta acid - “lupolones”
The process of breaking down alpha acids using heat is known as what?
isomerization
heating alpha acids produces “iso-alpha acids”
How long do hops need to boil to isomerize the alph-acid?
60-90 minutes.
What is the scientific name for lager yeast?
Saccharomyces Cerevesiae
What is the scientific name for ale yeast?
Saccharomyces Pastorianus.
Ale yeast work best at what temperature?
18-24 degrees Celsius
Lager yeast works best at what temperature?
1-14 degrees Celsius.
Non-Saccharomyces fermentation uses what types of microorganisms?
Lactobacillus, acetobactor and Brettanomyces.
What are the three Cs of brewing water?
Chlorine, Calcium and Carbonate.
What do brewers do with chlorine in water?
Remove it through charcoal filtration. Chlorine produces off flavors that give beer an antiseptic or burning wire aroma.
Is calcium in the water considered beneficial for brewing beer?
Yes. Calcium helps break down starch into fermentable sugar during mashing. It helps acidify the mash and wort and prevents gushing bottles.
Why do brewers grind the malt?
Milling is used to make the starch inside the kernel accessible during brewing.
What is ‘mash’?
Mash is a mix of ground malt and water. It is used to convert starch to fermentable sugar.
Name three base malts and three specialty malts.
Base Malt: Pilsner Malt, Pale Ale Malt, Munich Malt, Vienna Malt, Wheat Malt
Specialty Malts: Roasted Malts, Crytstal/Caramel Malts, Smoked Malts
Name the three key stages of malting and describe what happens during each.
Steeping: During steeping barley is soaked in water off and on for two to three days to trigger biochemical reactions that will start plant growth in the seed.
Germination: Barley is removed from water and kept moist for two to three days while a new barley plant begins to grow inside the seed.
Kilning: During kilning the malt is dried to facilitate long term storage, preserve enzymes, drive off DMS and develop malt flavor through toasting.
How would you define an ‘adjunct’ during brewing?
Adjuncts are starches or sugars that contribute fermentable extract from a source other than malt.
Describe the effect that an adjunct generally has on the flavor and body of the beer.
Adjuncts have little to no effect on flavor or body of beer. Adjuncts mostly contribute alcohol.
What conditions promote isomerization of alpha acids during brewing?
Heat. Isomerization happens when hops are boiled.
Why do hops need to be dried after picking?
Hops are dried to prevent spoilage during long term storage.
Moisture is reduced down to about 10%. Slow drying preserves aromas. Fast drying is good preserving bittering oils.
What are the major flavor differences between a beer made with lager yeast and a beer made with ale yeast.
Lager yeast contributes little to no flavor to finished beer. Ale yeasts produced fruity esters.
Name three water constituents of particular concern to brewers.
Calcium, Chlorine, and Carbonate.
Name a positive effect that calcium has on beer or the brewing process.
Prevents gushing bottles.
Alpha-amylase (an enzyme) needs calcium to break starch down into sugar.
During mashing calcium helps acidify the mash and the wort.
What is the first stage in the brewing process?
Grinding the malt.
List the 8 stages of brewing:
- Grind the Malt
- Mix ground malt with hot water to create a mash.
- Separate liquid (wort) from solids (spent grain).
- Boil the wort with hops.
- Separate hops and other solids from wort.
- Cool the wort.
- Conduct fermentation.
- Clarify, carbonate and package the beer.
During milling, what portion of the barley kernel should be kept as intact as possible? What portion should be broken up as much as possible?
Husk - kept as intact as possible.
Endosperm - broken up.
What is the second step in the brewing process?
Adding water to milled malt to make a mash.
What is the third step in the brewing process?
Separating the wort from the spent grain.
What is the basic goal of mashing?
Brewers combine crushed malts with hot water to convert complex starches into simple sugars, which yeast will convert in alcohol during fermentation.
Why would a brewer mash at different temperatures?
Brewers will change the temperature of the mash to influnce the composition of the wort and the character of the finished beer.
What is sparging and why is it performed as a part of the lautering process?
Sparging is the process where hot water is slowly added to the grain bed to help rinse the extract from the grain bed.
What effect does boiling have on the volume of the wort?
During the boil excess water is evaporated off and the volume of wort is reduced.
What two type of solids need to be removed from wort after the boil?
Spent hops and coagulated proteins.
Why do brewers add air or oxygen to cooled wort immediately before fermentation?
Yeast require oxygen to multiply properly have a healthy fermentation.
During what stage of fermentation does the most yeast growth and transformation of sugar into carbon dioxide and ethanol occur?
Primary fermentation.
Give three additional step usually undertaken at the brewery once beer has reached its desired flavor profile before it can be sold.
Clarification, carbonation, packaging.
What is bottle conditioning and what does it require?
Bottle conditioned beer undergoes a secondary fermentation in the bottle. A small, measured amount of sugar is added and the bottle is sealed. As the yeast ferments this sugar it carbonates the beer.
What are the three main structures of the barley kernel?
Husk, Endosperm and Embryo
Give three base malts and name a beer style that would be made with each one.
Munich Malt: Marzen, Festbier Vienna Malt : Vienna Lager Pilsner Malt - German Pils Pale Ale Malt: Best Bitter or Strong Bitter Wheat Malt: Weisse Bier
Describe what happens in the endosperm during germination.
Enzymes break down the dense protein matrix and cell walls around the starch granules. As a result the rock hard endosperm is transformed into a soft, chalky form.
Name the gland where hops store alpha acids and hop oils.
lupulin glands
Name three different physical forms of hops commonly used by brewers.
Whole hops, pellet hops, hop extracts.
If a brewer says they are using a POF (or PAD) yeast strain, what flavors would you expect in their beer?
Phenolic Off Flavors - black pepper and clove flavors.
PAD - Phenyl Acrylate Decarboxylase
What off flavors might result from improper milling and how would they be caused?
If the husk is ground too finely too many phenols and tannins will be extracted. This will give the finished beer a harsh astringent flavor.
Name three negative effects that arise if brewing water is very low in calcium from all sources.
Low calcium can reduce enzyme activity which can contribute haziness to finished beer.
Yeast need calcium to properly convert sugar to alcohol.
During bottling low calcium can lead to gushing bottles.
Name the mineral responsible for ‘temporary hardness’ and state what negative flavor characteristics can be attributed to it in pale, bitter beers.
Carbonate causes ‘temporary hardness’ and gives pale, hoppy beers an unpleasant flavour.
Why have brewer stopped using decoction mashing in most cases?
Decoction mashing uses a lot of energy and is time consuming.
What off flavours might result from an improperly conducted lautering?
Sparging for too long or using water that is too
Name five physical and chemical changes that occur in wort during the boil.
- Colour and flavour develop due to caramelization and Maillard reactions.
- Evaporating excess water to achieve desired volume of wort.
- Bacteria is killed as the wort is sterilized.
- Stripping undesirable VOCs, such as DMS, from wort.
- Isomerizing alpha acids to develop bitterness in the beer.
- Extracting hop oils responsible for hop flavour and aroma.
- Coagulating excess protein.
Describe how a whirlpool achieves separation of liquids from solids.
The whirlpool creates a current that deposits solids in a cone formation at the center of the bottom of the tank.
What brewing processes are accomplished in a coolship and how does it work?
A coolship is used to cool the mash and separate the solids from the liquid. The coolship is sized so that the wort is 8-12 inches deep. The shallow depth allows the solids to drop out quickly and a large surface area helps the wort cool more quickly.
What role does fermentation temperature control play in the flavour of a finished beer?
Yeast strains have a temperature range in which they will produce the expected flavours. Fermenting at temperatures outside of the range will change the flavour of the beers. Fermenting at too high a temperature will produce excess fruity esters. Cooling the temperature too quickly can produce diacetyl, acetylaldehyde, and sulfure aromas in the beer.
What off flavours might result from issues during beer filtration and packaging stages?
Stale flavours can result from exposure to oxygen at this stage. Exposure to bacteria and wild yeast can produce off-flavours such as acetic acid, diacetyl, lactic acid and phenols.
What off flavours might result from issues during beer filtration and packaging stages?
Stale flavours can result from exposure to oxygen at this stage. Exposure to bacteria and wild yeast can produce off-flavours such as acetic acid, diacetyl, lactic acid and phenols.
What component of hops is responsible for aroma and flavour properties?
Hop oils.
What is malt? How is it different than raw grain?
Malt is grain that has been germinated and then the germination is stopped by drying it with hot air. Malting grain breaks complex starches down into simple sugars to make them more available for fermenting.
What grain, or grains are usually used to make malt for brewing?
Barley is the primary grain used in brewing beer. Wheat, oats and rye are also used, but usually in combination with barley.
Name a non-Saccharomyces yeast that might be used in making beer.
Brettanomyces.
What unmalted grain might be used in making American style lagers?
Corn and rice adjuncts are used in American style lagers.
Why don’t brewers use ‘pure’ water for brewing?
Many of the minerals necessary for fermentation are found in water. Water that has been purified no longer has those minerals.
What water mineral(s) favor production of pale, bitter beers?
Calcium sulphate (gypsum) helps to produce a clean, crisp bitterness in hoppy pale ales.
At what point in the brewing process is most starch broken down into fermentable sugars?
Mashing.
What must be done to malted barley before it enters the mash tun?
It must be ground or milled.
After mashing, what operation is performed to separate the sugar-rich wort from the spent grain?
Lautering.
At what step in the brewing process is sugar converted into alcohol and carbon dioxide?
Fermentation.
At what step in the brewing process are alpha acids extracted from hops and isomerized or converted into their bitter form?
Boiling.
What step in the brewing process separates spent hops and coagulated proteins from the liquid wort?
Separation and cooling.
What is a typical fermentation temperature for ales?
65-75 degrees Fahrenheit (18-24 degrees Celsius)
What is a typical fermentation temperature for lagers?
33-58 degrees Fahrenheit (1-14 degrees Celsius)
At what temperature is beer typically held during the lagering phase of lager beer production?
31-38 degrees Fahrenheit or -1 to -5 degrees Celsius.
Other than filtering, name another method for clarifying beer.
Centrifuge
