Part IV, Section A: Beer Ingredients and Brewing Processes

Question 1

What are the 4 main ingredients in beer?

BES Card #213

Answer 1

1. Grains (malt)
2. Hops
3. Yeast
4. Water

Question 2

What is the primary purpose of using grains in beer?

BES Card #214

Answer 2

They are an excellent source of starch and contain enzymes that convert those starches to fermentable sugars by fermentation.

Question 3

What are the 3 steps for malting grain?

BES Card #215

Answer 3

1. Steeping (almost 4 hours)
2. Germination (4-5 days)
3. Drying
   a. kilning
   b. roasting

Question 4

What are some unmalted grains used in beer?

BES Card #216

Answer 4

Buckwheat
Corn
Oats
Rice
Rye
Sorghum (millet)
Unmalted barley
Unmalted wheat

Question 5

What are hops?

BES Card #217

Answer 5

Hops (humulus lupulus) are small, green, pinecone-like flowers that grow on a bine (a vine-like plant).

They act like a spice and have strong flavor concentration so small quantities are needed.

Each variety of hop (over 100 varieties) has its own unique flavor.

They are added to beer at several stages:
1. Early in the boil for bittering
2. Middle of the boil for flavoring
3. Late in the boil for aroma
4. After fermentation (dry hopping) for super concentration of aroma

Question 6

How do hops affect beer flavor?

BES Card #218

Answer 6

Hops add bitter flavors to offset the sweetness
from malt. They also add aromas and act as a preservative.

Question 7

What are 2 chemical compounds in hops and how does each affect beer?

BES Card #219

Answer 7

1. Alpha acids – These are converted with heat into Isoalpha acids which are intensely bitter
2. Beta acids – Beta acids are a component of hop resins responsible for contributing volatile aromatic properties to beer flavor profiles. Beta acids contribute no bitterness. Because they are more volatile than alpha acids, they also do not require heat for their extraction

Both have antimicrobial and preservative properties.

Question 8

What are bittering hops?

BES Card #220

Answer 8

Bittering hops have more alpha acids.
They are added earliest to the boiling wort.

Question 9

What are aroma hops?

BES Card #221

Answer 9

Aroma hops have more beta acids.
They are added at the end of the boil (late hopping), or after fermentation without high heat (dry hopping).

Question 10

What are the major growing regions of hops?

BES Card #222

Answer 10

Hops grow in moist, temperate climates, mostly
near the 48th parallel north.

Germany
Czech Republic
Britain
Yakima Valley, Washington, USA
Willamette, Oregon, USA
Idaho, USA

And the 30th-40th parallel south:

Australia (south Tasmania and North East Victoria)
New Zealand (Nelson (northern) region of the South Island

Question 11

What is yeast?

BES Card #223

Answer 11

Yeasts are microscopic, single-cell fungi.
They eat sugar, and excrete carbon dioxide and
alcohol.

Question 12

What are the 2 broad categories of yeast used in beer?

BES Card #224

Answer 12

1. Ale yeast
2. Lager yeast

Question 13

What is ale yeast?

BES Card #225

Answer 13

Ale yeast: Saccharomyces cerevisiae
Also called Brewer’s Yeast. Ferments best at 68-72° F (20-22° C) and tends to prefer the top of the fermenting vessel

Flavors from esters: fruity; banana, apple, pear, sometimes peach and apricot
Flavors from phenols: clove, nutmeg, allspice, ground white, and black pepper

Question 14

What is lager yeast?

BES Card #226

Answer 14

Lager yeast: Saccharomyces pastorianus

Ferments best at 45-55° F (7-13° C) and tend to prefer the bottom of the fermenting vessel.

Flavors: not many ester or phenol flavors, so the beers feature the flavors of the malt and hops

Question 15

What are 3 other yeasts and 3 bacteria used in beer fermentation?

BES Card #227

Answer 15

Other yeasts (the so-called ‘wild yeasts):
1. Brettanomyces
2. Pichia
3. Candida

Fermenting bacteria:
1. Lactobacillus
2. Pediococcus
3. Acetobacteria

Question 16

What is the largest component of beer?

BES Card #228

Answer 16

Water. Water makes up about 90% of beer by weight
and by volume.

Question 17

What are the 4 minerals in water that affect beer flavor and brewing?

BES Card #229

Answer 17

1. Calcium
2. Magnesium
3. Sulfur
4. Chloride

Question 18

What are the 3 main steps to making beer and what is the purpose of each?

BES Card #230

Answer 18

1. Mashing – Convert the malt starches into sugar
2. Boiling – Sterilize the wort, concentrate the
   sugars, and break down the proteins, and add the hops
3. Fermentation – Yeast converts the sugar into
   carbon dioxide and alcohol
   Also: Packaging – Put the finished beer
   into kegs, bottles, or cans. It can be force-carbonated or bottle conditioned.

Question 19

What is the chemical produced by hops that gives bitterness?

Answer 19

Isoalpha acids

Question 20

What do we mean by ‘diastatic power’ in malt?

Answer 20

Diastatic power refers to the enzymatic power of the malt itself – its ability to break down starches into even simpler fermentable sugars during the mashing process. The term “diastatic” refers to “diastase” enzymes.

If you don’t have sufficient diastatic enzymes in your mash, you simply will not be able to properly convert sugars during the mash.

Question 21

What are diastase enzymes?

Answer 21

There are two “diastase” enzyme groups:

α- and β-amylase are not individual enzymes but categories of enzymes that evolved to do similar things in different contexts

1. α-amylases are produced by plants, bacteria, and animals (including humans) and break down starches at random points, creating everything from glucose on up.
2. β-amylases aren’t produced by animals at all, but many variations have evolved in plants. They work by chewing off individual maltose molecules from the ends of longer starches

Question 22

What is the temperature range for mashing barley and wheat malts?

Answer 22

148-158F

Question 23

What units do we use to measure diastatic power?

Answer 23

Diastatic Power is measured in degrees lintner (°L)
In Europe, a different scale is used, the Windisch-Kolbach units (°WK).

Question 24

What causes malt to lose its original diastatic power?

Answer 24

The hotter a grain is kilned, the less its diastatic activity. As a consequence, only lightly colored grains can be used as base malts, with Munich malt being the darkest base malt generally available

Question 25

What is the range of diastatic power of commonly used malts?

Answer 25

0 - 180 or above

** Examples

Briess Red Wheat Malt:  180 °L 
American 6 Row Pale Malt: 160 °L 
American 2 Row Pale Malt: 140 °L
Maris Otter Pale Malt: 120 °L
German Pilsner Malt: 110 °L
Munich Malt (10 SRM): 70 °L
Wheat Malt, German: 60-90 °L
Belgian Pale Malt (2 row): 60 °L
Vienna Malt: 50 °L
British Pale Malts: 40-70 °L
Munich Malt (20 SRM): 25 °L
Wheat, Unmalted (flaked, Torrified): 0 °L
Crystal Malt (all): 0 °L
Chocolate Malt: 0°L
Black Patent Malts: 0 °L

Question 26

Lager yeast ferments best at what temperature? and where does that fermentation tend to take place?

Answer 26

Ferments best at 45-55° and tends to do its work toward the bottom of the vessel

Question 27

Ale yeast ferments best at what temperature? and where does that fermentation tend to take place?

Answer 27

Ferments best at 68-72° F and tends to do its work toward the top of the vessel

Question 28

What is yeast ‘flocking?’

Answer 28

Flocculation is the tendency of yeast cells to aggregate together, forming a multicellular mass and sedimenting rapidly from the suspended medium or rising to the surface. It occurs near the end of the fermentation process.

Lager yeast strains aggregate into large groups, rapidly sedimenting to the bottom of the fermenter, while ale strains may rise to the surface to form a thick top layer.

Yeasts have 3 categories of flocculation

High:
-starts to flocculate the earliest, which can leave behind some unfermented sugars or unwanted flavor compounds such as diacetyl
-may require recirculation of the beer late in the fermentation to re-suspend the yeast, allowing the fermentation to finish to the desired attenuation
- they can produce a brighter beer with less suspended yeast, making filtration easier

Medium:
- are some of the more commonly used strains, and will start to flocculate out as sugars become less abundant. Often they need help in order to flocculate, and this can be accomplished by cooling the fermenter to lower temperatures

Low:
- stay in suspension well after fermentation has ended. These strains tend to be wheat beer strains in which low flocculation is desirable, as the finished beers are meant to be hazy with yeast

Yeast that is used over a number of generations can be selected in a manner that may increase or decrease a yeast strain’s flocculative tendencies. In a fermenter with a cone bottom, yeast collected from the bottom of the cone will be the yeast that flocculated early, while yeast collected from the top layer of sediment will be the yeast that flocculated last. By continuously selecting for these tendencies, many brewing strains can be “trained” to perform in a manner that better fits the brewery’s needs.

Question 29

What is a diacetyl rest?

Answer 29

A fermentation step used by brewers to eliminate the common beer off-flavor, diacetyl.

The diacetyl rest occurs at 68°F for a few days to ensure that yeast reabsorbs diacetyl, removing the butter-like flavor from the beer.

This procedure is most common in lager brewing because yeast can only reabsorb diacetyl at warmer temperatures.

Ales don’t typically need a diacetyl rest because they ferment in the temperature range that yeast can reabsorb diacetyl.

Question 30

How are gluten-free beers made?

Answer 30

Two methods exist.

Method I.

The mash will only contain gluten-free grains, some adjuncts in normal beer, such as:

Buckwheat
Corn
Flax
Quinoa
Rice
Sorghum (millet)

These are then gelatinized by boiling or heating, and then raw enzymes are added in liquid form to break down the sugars and brewed in the remaining normal steps

These beers often have slightly different aromas and flavors from regular beer.

Method II.

This method is to produce a beer using a gluten-containing malt (wheat, barley, or rye), and then introduce a process to reduce the gluten content so that it complies with the law on gluten-free and contains 20 ppm or less of gluten. One way of doing this is to use an enzyme at the start of the fermentation process to break down the gluten protein.

An example of this is the patented product Brewers Clarex® (also used to reduce the chill haze in beer). This protease enzyme degrades the gluten to levels below the 20 ppm threshold so it can be labeled gluten-free. As this type of beer has been made from barley, by law the labeling must also state ‘contains barley’.

Question 31

What are the 3 main types of mashing?

Answer 31

1. Infusion mashing
2. Decoction mashing
3. Temperature-controlled infusion mashing.

Question 32

What is infusion mashing?

Answer 32

In the UK most ales are traditionally brewed using an infusion mashing process where good-quality, well-modified malt is mashed into a “mash tun,” where it is held at approximately 65°C (149°F) for at least 1 h. During this hour, the malt sugars and other materials are released from the grist by action of enzymes in the malt. The mash is then sprayed with hot water, called sparging (at about 75°C [167°F]), which runs through the mash and out of the mash tun through a slotted false bottom, taking with it all the soluble material that forms the wort, the sweet liquid that the yeast will ferment into beer. This infusion process is sometimes called isothermal infusion mashing, because only one temperature is used. It is made possible because barley-growing conditions in the UK are ideal for the production of very well-modified malt. When well-modified malts are produced, many of the enzymic processes to break down the proteins, hemicelluloses, and gums have already taken place in the malting house. Infusion mashing has always been used in the UK to produce ales, and it remains the simplest mashing process. As the quality of malting barley improves, infusion mashing is used by many craft brewers to brew lagers, wheat beers, and other types of beers. Because the infusion mashing method requires only two brewhouse vessels (a mash/lauter vessel and a kettle) to produce hopped wort, it is still widely used among small breweries and pub breweries.

Question 33

What is decoction mashing?

Answer 33

One of two types of mashing.

Decoction mashing is a traditional and intensive method of mashing. While the method was once used by most breweries, today decoction is a controversial topic among brewers. Many German brewers (among others) claim that it develops malt character, depth, and superior foam. Others feel that it is a waste of energy and time, and is unnecessary now that modern well-modified malts are available to everyone.

The basic principle of decoction is to remove a part of the mash, boil it, and return it to the main mash, which is held at a constant temperature. There are two different aims in boiling one part of the mash:

1. To use physical pulping, which impacts the cell walls of the malt.
2. To raise the temperature of the bulk mash to a defined higher temperature after mixing both parts. (In the days before thermometers, the decoction method made a multi-temperature mash achievable and repeatable.)

The boiling of the grains helps to destroy the cell walls and makes the starches more accessible to the malt enzymes. This is particularly important for under-modified malts where boiling helps to break down the cell walls.

There are different types of decoction mashing methods. The archetype is the triple decoction. This very intensive method is, from the current point of view, time-killing and no longer very popular, but it is the basis for understanding the principles behind all decoction methods.

The mash-in temperature is 95°F–98.6°F (35°C–37°C) with one part malt and three parts of water.

The triple decoction mash employs three main temperature rests: the acid rest, the protein rest, and the saccharification rest.

Question 34

What is a temperature-controlled infusion mash?

Answer 34

Most lager brewers and larger ale brewers outside the UK employ a process called temperature-programmed infusion mashing. This process involves heating an infusion mash through a series of temperature rises and then resting the mash at that temperature for a specified period before rising to the next temperature.

These temperature rests are sometimes called “stands.” Heating of the mash is carried out by passing steam or hot water through heating panels within the walls of the mashing vessel, which is also fitted with an agitator to ensure good mixing. This process normally starts by mashing the malt at approximately 45°C–50°C (113°F–122°F) into a mashing vessel, sometimes called a conversion vessel. The mash is often held at this temperature for anywhere from 10 to 25 min, during which enzymes work on the protein and gums in the grist to release the starch from which the malt sugars are made. The proteins must be broken down to form amino acids; these are valuable yeast nutrients during fermentation. Higher-weight protein materials are also broken down, lest they later contribute to unwanted haze in the finished beer. Other proteinaceous material is also a contribution to beer foam, and too long a stand at 45°C (113°F; called a protein rest or stand) can be deleterious to a beer’s foaming quality. After the protein rest, the mash is heated to 62°C–67°C (143.6°F–152.6°F) for the saccharification stand. The enzymes (called amylases) that break down starch and bigger sugar molecules into fermentable sugars work best at this these temperatures. The amount of sugar produced in the mash is largely a function of the amount of grist used. However, different saccharification temperatures will produce different sugars in the wort and therefore different beers. Mashes performed with low saccharification temperatures produce a greater proportion of fermentable sugars in the resulting wort and will produce a drier beer with higher alcohol content. Conversely, saccharification temperatures toward the top of the range will result in less fermentable worts and sweeter, more full-bodied beers, and these will have a lower alcohol content produced from the same amount of grist. The final stage is to heat the mash up to about 75°C (167°F) prior to transfer to a mash separation vessel, usually a lauter tun. See Lauter tun. This final heat rise deactivates the enzymes and reduces the viscosity of the wort, thus giving a faster runoff. This is often referred to as “mashing off.” Some beer types are best brewed using specially tailored temperature-programmed infusion mashes that will perform different functions. For example, many wheat-based beers are mashed with longer protein rests (wheat having more protein than malting barley) or other rests designed to favor the production of certain flavors in the finished beer. The brewer can therefore fine-tune the wort to create exactly the flavor and aroma desired.

Question 35

What is step mashing?

Answer 35

Step mashing is a technique that was developed by brewers at a time when malts were less well modified than they are now. When malting takes place the aim is to break down glucans and proteins, making it easier for home brewers to extract sugars. By performing different rests at different temperatures, brewers could perform some of this modification in the mash, increasing the amount of sugar they could extract from the malt and therefore increasing their efficiency.

The 4 steps are:

1. The Acid Rest: 35-45°C (95-113°F)
2. The Ferulic Acid Rest: 43-45°C (109-113°F)
3. The Protein Rest: 44-59°C (113-128°F)
4. The Saccharification Rest: 61-71°C (142-162°F)

Question 36

What is malt modification?

Answer 36

This refers not to some process done to change malt characteristics but a natural feature of the malt itself.

Modification denotes the chemical breakdown of compounds that reside naturally in grain and how easily this is done for each particular type of malt. It is expressed as a percentage value, for the entire batch from which the sample was taken. The brewer will look for a modification level that suits the beer being made and the brewing technique employed. Single-temperature infusion mashes tend to require malts with high modification percentages, but brewers employing temperature-programmed mashes can use less modified malts and those using decoction can use malts that other brewers would find undermodified.

Question 37

What is an acid rest in mashing?

Answer 37

A step designed to lower the pH of the mash (by which we mean make it more acidic). Due to the temperature range this step can also be useful for breaking down beta-glucans which can be useful if using a high proportion of wheat or oat malts. An acid rest works because at this temperature, phytase enzymes are actively breaking down phytin molecules. This releases phytic acid which lowers the mash pH. The heat used in the malting process is enough to destroy most of the phytase present so an acid rest will only work in extremely lightly kilned malts and an acid rest takes at least an hour before there is any significant change in mash pH which is why this rest is not more widely utilised today or if it is, it is for the beta-glucan breakdown effects rather than mash pH effects.

Question 38

What is a ferulic acid rest?

Answer 38

In beer, a molecule called 4-vinyl-guaiacol (catchy) is credited with giving beer a clove-like aroma that is desirable in some styles. Ferulic acid is a pre-cursor to this molecule which is normally bound to other molecules present in the wort. By performing a rest in this temperature range you can release more ferulic acid into the wort, giving you more of the precursor to 4-vinyl-guaiacol.

Question 39

What is a protein rest in mashing?

Answer 39

If you have too many long chain proteins present in your wort you may find you have issues with protein haze and instability if you store your beer for any period of time. Conversely you require some medium chain proteins in your beer as they help with head retention and body in the finished beer. Implementing this rest theoretically breaks down protein chains into shorter chains. It is best avoided unless you are using malt that is very high in proteins as with most well modified malts, a rest at this temperature is only going to negatively affect head retention.

Question 40

What is a saccharification rest in mashing?

Answer 40

Saccharification, literally “to make into sugar,” the conversion, by enzymes, of starches into sugars and dextrins during the mashing process. Saccharification of cereal starches into fermentable sugars and unfermentable dextrins creates the basis of the wort, a sugary solution that is later fermented into beer. See wort. Saccharification during the mash is achieved by the activation of malt enzymes at the correct temperatures and moisture levels. To be susceptible to digestion by enzymes, the starches in barley malt must first be gelatinized. Barley malt starches gelatinize at temperatures between 61°C and 65°C (142°F and 149°F). Most adjunct starches, such as corn grits or rice, require higher temperatures for gelatinization and are therefore cooked separately before being added to the mash for saccharification. See cereal cooker. Once the starches are gelatinized, they are broken down by beta amylase and alpha amylase into sugars, principally maltose. Alpha amylase is primarily responsible for the hydrolysis of starches into dextrins, and beta amylase digests dextrins into fermentable sugars. The enzymes themselves are rapidly denatured by higher temperatures. At 65°C (149°F), beta amylase is almost completely deactivated with 30 minutes, whereas alpha amylase survives somewhat longer. The time period and temperature(s) at which the mash is held to effect saccharification is called a “saccharification rest.”

Question 41

How are adjuncts ‘mashed’?

Answer 41

They use a variation on decoction mashing as adjuncts need to be boiled to gelatinize their starches. Almost all American mass-market beers are brewed using a version of this technique, and it is also widely used to produce light-bodied, light-flavored lager beers throughout the world.

These variations of decoction processes are also often used when unmalted cereals, usually corn grits or rice, are used as adjuncts in the mash. The unmalted cereal (a small portion of malted barley is also added) is mixed with hot water in a separate vessel (usually referred to as a “rice cooker” or “grits cooker”) and this mash is heated to 100°C (212°F). The hard starches in the raw grains gelatinize at this temperature, rendering them soft and susceptible to breakdown by enzymes. When this “cereal mash” is added to the barley malt mash, the enzymes in the malt will convert the now-gelatinized cereal starches into sugars.

Question 42

What is Parti-Gyle Brewing?

Answer 42

Parti-gyling means getting multiple beers out of the same mash. The brewer boils successive runnings separately, and then, ideally, blends them to different strengths.

For the average homebrewer, this appears to be slightly insane. One mash/one boil works well enough, and our time is precious. Why add extra boiling and chilling, not to mention extra pots and fermentors?

For brewers of a certain era, however, parti-gyling was the sensible thing to do. It had clear advantages. And for commercial brewers with the right setup, it still has those advantages today.

You make one beer out of the stronger first runnings, another beer out of weaker second runnings, and possibly even a third or more beers from additional runnings.

“Separate runnings is legitimate parti-gyling,” Keeling says. But that’s the crude way, and it ignores roughly 230 years of better practice. Keeping those worts separate means that you miss two of the great advantages of this technique: blending worts to hit target gravities, meanwhile making more types of beer.

To illustrate how it works, Keeling describes an approximation of a typical run at Fuller’s. He brews two worts from the mash—the first runnings hit about 1.080 gravity, while the second runnings come in at about 1.020. At least three beers come out of those two worts: Extra Special Bitter (ESB), London Pride, and Chiswick Bitter, going from strongest to weakest. Each beer is a blend of both worts. (Sometimes the same mash also produces Fuller’s stronger ales, such as Golden Pride or Vintage Ale. Even those beers get a small portion of the weaker wort.)

Question 43

What is Speise?

Answer 43

(shpiy-zuh)
Speise is German for ‘food’. Used for bottle conditioning: Unfermented sterilized wort mixed with yeast before bottling. This is an alternative to adding priming sugar and gets around the reinheitsgebot restriction of adding sugar.

Question 44

What is kraeusen-ing?

Answer 44

(kraeuse = kwoy-zuh)
Krausening is a traditional German method using actively fermenting wort to:

1. Used to induce fermentation in a different batch of beer, or
2. For bottle conditioning, carbonating beer without using sugars or other adjuncts.

Question 45

What is attenuation?

Answer 45

Attenuation refers to the conversion of sugars into alcohol and carbon dioxide by fermentation; the more attenuation, the more sugar has been converted into alcohol. A more attenuated beer is drier (less sweet) and more alcoholic than a less attenuated beer made from the same wort.