LOVING THE MASH:Its Not A Four Letter Word

The BJCP Exam 2011

Richard De PalmaNew York City Homebrewers Guild

Westchester Homebrewers OrganizationMay 2011

MASH

• “I believe the most important part of brewing a great beer takes place in the mash. This is really where beer is made.”

Michael “Mufasa” Fergeson

• “Mashing is the heart and soul of brewing.”Randy Mosher

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The Brewing Process• The Idea: brew a beer• Recipe formulation• Ingredient procurement and

processing

• THE MASH• The Boil (including hop

additions)• Cooling• Fermentation• Racking• Carbonation• Packaging• Drinking

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The M-word“Its that M-word: Mashing. The beast in the homebrew closet. A snarling tangle of chemistry, hoses, uncertainty, and chances for things to go terribly wrong.

Well, a monster can be a pussycat if you just scratch its ears the right way.”

Randy Mosher, Radical Brewing 37 (Brewers Publ. 2004)

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MASH: What Is It?“Mashing is mixing crushed malted [and

unmalted] cereal grains (the grist) with water at a certain ratio for specific times at specific temperatures.”

Gordon Strong, Brewing Better Beer 29 (Brewers Publications 2011).

“Mashing is the term for the hot water steeping process that hydrates the malt, gelatinizes its starches, releases its natural enzymes, and converts the starches into fermentable sugars.”

John J. Palmer, How to Brew, 141 (Brewers Publications 2006). 5

MASH: What Is the Goal?

WORT PRODUCTION:• taking (mostly) grain–

based raw ingredients and turn them into wort: the nutrient-rich, highly fermentable, sugar-laden soup that we then flavor with hops (and other spices) and ferment using yeast, to make beer.

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Isn’t there more to it than that?

Yes.

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What Characteristics of The Finished Beer Can be Manipulated in the Mash?

Virtually all of them:• Flavor• Body• Mouthfeel• Aroma• Fermentability• Alcohol Content• Color

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In Order to Understand The Mash and Make the Right Choices To Achieve

Your Target Wort, You MUST Understand the Role of ENZYMES!

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ENZYMES• “Enzymes”: amazing protein molecules located in the

grain and developed during the malting process.• Enzymes are “catalysts”: a material that participates in

a chemical reaction without being altered.

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ENZYMES• In the mash, enzymes systematically break down

complex carbohydrates, proteins and other constituents in the grains to produce fermentable sugars and other desirable compounds and conditions.

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ENZYMES

“brewing itself can be regarded as a series of enzyme-mediated

reactions.” George Fix, Principals of Brewing Science 40 (Brewers Publ. 1989.

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ENZYMES

• Characterized by “specificity”: each enzyme works on only a few (perhaps only one) “substrate” to drive a very specific reaction

• “Lock and Key” Theory:

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ENZYMES

Carbohydrates = Carbohydrase

Glucans = Glucanase

Proteins = Proteinase

• Examples:• Enzymes that break down:

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ENZYMES• Enzyme activity is directly affected by:

Temperature

pH

Pressure

This is the key to understanding the Mash 15

ENZYMES

Enzyme OptimumTemperatureRange

Working pH Range Function

Phytase 86-126°F 5.0-5.5 Lowers the mash pH. No longer used.

Debranching (var.) 95-113°F 5.0-5.8 Solubilization of starches.

Beta Glucanase 95-113°F 4.5-5.5 Best gum breaking rest.

Peptidase 113-131°F 4.6-5.3 Produces Free Amino Nitrogen (FAN).

Protease 113-131°F 4.6-5.3 Breaks up large proteins that form haze.

Beta Amylase 131-150°F 5.0-5.5 Produces maltose.

Alpha Amylase 154-162°F 5.3-5.7 Produces a variety of sugars, including maltose.

Table 11 - Major Enzyme Groups and Functions

Note: The above numbers were averaged from several sources and should be interpreted as typical optimum activity ranges. The enzymes will be active outside the indicated ranges but will be destroyed as the temperature increases

above each range.

John J. Palmer, How to Brew, 143, Table 11 (Brewers Publications 2006)16

ENZYMES

“One of the biggest misconceptions about enzymes is that they work like transistors or diodes – that they just switch on or off under specific conditions. Don’t think of a switch, think of a bell curve – there is a region where the enzymes are most active, but they are still functioning outside the prime temperature range.”

Gordon Strong, Brewing Better Beer 29 (Brewers Publications 2011)

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ENZYMES

• Denaturing: irreversible process by which enzymes break down by (usually) being exposed to heat beyond their normal functioning range.

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The Mash Process: Control

• Mashing is the process by which we use specific temperatures and pH ranges to control enzymatic activity, creating the wort we desire.

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The Mash Process

• Both malted and unmalted grains have their starch reserves locked in a tightly packed protein/carbohydrate matrix that prevents the enzymes from being able to access the starches for conversion to the more simple sugars that yeast can ferment.

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The Mash Process

• Modification: the degree to which cell walls and the protein/carbohydrate matrix in the endosperm is broken down during malting.

• Most commonly used indicator of modification is the soluble-to-total protein ration (aka Kolbach Index)– 30-35% = under-modified– 36-40% = moderate– 40-44% = well-modified– 44-48 = highly modified

• Degree of modification can drive the type of mash regime you use.

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The Mash Process

• Before the enzymatic reactions can take place, the malt must be pre-processed:– Milling: individual kernals are cracked open

to expose the starchy endosperm– Liquifaction: starch granules take up water

in the mash naturally; aided by α-amylase which penetrates starch skin and aides water uptake

– Gelatinization: starch literally bursts open making it accessible to enzymatic attack; occurs for malt at 60° - 65°C (140° - 150°F)

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The Mash Process

• Strike Water Volume and Temperature– Water to Grain Ration

• Mash tun capacity• Enzymatic considerations – thinner mash

creates a more fermentable wort• Uniformity of temperature of mash• System water loss (pumps, hoses, false bottom)

– Strike water temperature• Temperature of grain• Thermal mass of mash tun• Target temperature after dough in

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TYPES OF MASH REGIMES

• SINGLE INFUSION

• STEP INFUSION

• DECOCTION

• DOUBLE MASH

• SOUR MASH

• PARTI GYLE

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SINGLE INFUSION MASH• Single saccharification rest for entire mash

– Temperature considerations: usually between 148°-155°F

• Lower temperature favor β-amylase activity – more fermentable wort

• Higher temperature favors α-amylase activity – less fermentable wort

– Time considerations: usually one hour• Actual conversion usually within 30 minutes• At lower temperatures, may lengthen rest time,

e.g., seventy-five or ninety minutes • Test for conversion – iodine, taste 25

SINGLE INFUSION MASH• Used for today’s well modified malts

– Starches and proteins converted during malting

– Protein rests with well-modified malts may deteriorate medium molecular weight proteins needed for head retention

• Most used by pro brewers– Most economical

• Single vessel• Less energy• Less time 26

SINGLE INFUSION MASH

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VORLAUF• Recirculate the wort through the mash bed

– Helps make mash temperature uniform– Sets the grain bed as a filter– Clarifies the wort

• manually• pumps• gravity (?)

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MASH OUT• Mash Out: 168°-170°F.

• Denatures enzymes and fixes the fermentable sugar composition of the wort.

• Also, thins the mash, making it easier to lauter.

• Do not allow water to be too hot (above 170º F), can cause extraction of tannins and other harsh and astringent materials from the grain husks.

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LAUTER AND SPARGE• Lauter is the process by which the wort is

separated from the grain husks and other left over materials in the mash– Same vessel or separate vessel– whirlpool

• Sparging is the “rinsing” of the grain to obtain the sugars for transfer to the boil kettle – Batch sparging– Fly sparging– No sparge

• pH (above 8) and water temperature (above 170º F) can cause extraction of unwanted harsh and astringent flavors (tanninis in husks)

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STEP MASH• Similar to single infusion, but where the

wort is raised through successive “steps” or rests to activate multiple enzymatic reactions

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STEP MASH• Temperature raises

– Direct fire– Steam– RIMS– HERMS– Decoction

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STEP MASH• Common Mash Rests

– Ferulic Acid Rest: 111°-115°F (20 minutes) to develop ferulic acid in weizens metabolized by weizen yeast to create 4-vinyl guaiacol

– β-Glucanase Rest: 98°-113°F (20 minutes) if a large percentage of starchy adjuncts (unmalted and flaked wheat, rye or oats) are used: breaks down gummy glucans

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STEP MASH• Common Mash Rests

– Protein Rest: 122°-131°F (10-20 minutes) to allow proteolytic enzymes to work, principally proteases and peptidases; in undermodified malt, can create medium-weight molecular proteins that can reduce chill haze and help with head retention. Skip with well-modified malts (e.g., British and U.S. pale malts). Pilsner malts and under-modified German malts may benefit. Also use if high percentage adjuncts (with a β-glucanase rest)

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STEP MASH• Common Mash Rests

– β-Amylase Rest: 142°-149°F (60 minutes). This is the primary saccharification rest. β-amylase drives the reactions which cleave the ends of long chain starches off, forming maltose. Works well in a pH of 5.0 to 5.6 range.

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STEP MASH• Common Mash Rests

– α-Amylase Rest: 154°-162°F (60 minutes). This is the other saccharification rest. α-amylase drives the reactions which also create more longer-chain, unfermentable sugars, such as dextrins, in addition to forming maltose. Works well in a pH of 5.1 to 5.9 range.

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STEP MASH

George Fix, Principles of Brewing Science 96, Table IIA-2 (Brewers Publ. 1989)

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DECOCTION MASH

Historical German and Czech Method of Mashing

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Still used with under-modified malts, particularly German and Czech (Moravian) pilsner malts, to obtain significant maltiness in a dry beer.

DECOCTION MASH• Typically mash is begun at a low temperature

rest, i.e., acid or protein rest• A portion of the mash (the “decoction”) is

removed to another kettle and raised to saccharification temperature for a short rest, and then boiled for 20 minutes or more.

• The “decoction” is then returned to the main mash, which raises its temperature of the main mash to the next rest.

• Repeat.• Mash out. 39

DECOCTION MASH• The decoction removed can be either “thick” or

“thin” (relatively) – 30-40% of mash– 1 qt thick mash for each pound of grain

• In the decoction, the malt kernal is exploded by the boiling and allows more complete access to the starch for conversion

• Tannins are not a worry because of the low pH• The enzymes are left in the main mash so they

are not denatured on work on the returned “decoction” to create more complete saccharification 40

DECOCTION MASH• Single, Double and Triple Decoctions

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OTHER MASHES AND RELATED CONCEPTS

• DOUBLE MASH

• SOUR MASH

• PARTI GYLE

• Mini-Mash

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Brewhouse Efficiency

• Brewhouse efficiency equals the percentage of potential extract your brewhouse actually obtains from the ingredients

• My brewhouse efficiency is ~70% • Professional Brewers strive for above 90%• Extreme efficiency imparts astringent

characteristics• Ingredients like sugar, extract, honey and maple

syrup have a 100% efficiency (in boil)43

Don’t Stress

• There are specific questions on the BJCP exam that require knowledge of the mash, its processes and reactions, including the role of enzymes

• These questions are already available for you to use to focus what you need to know about the mash for the exam.

• Take practice questions and write out full answers – it will help a lot in getting a passing score!

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BJCP EXAM QUESTIONSTroubleshooting

T1. Describe and discuss the following beer characteristics. What causes them and how are they avoided and controlled? Are they ever appropriate and if so, in what beer styles? (three will be given). Address the following topics:

3 points: Describe each characteristic.

4 points: Identify the causes and controls for each characteristic.3 pointsIdentify appropriate/inappropriate styles.

The choices will be drawn from:

a) cloudiness b) buttery c) low head retention

d) astringency e) phenolic f) light body

g) fruitiness h) sourness i) cooked corn

j) bitterness k) cardboard l) sherry-like

m) acetaldehyde n) alcoholic 45

BJCP EXAM QUESTIONSTroubleshooting

T2. Explain how the brewer gets the characteristics a) good head retention, b) clarity in a beer, and c) a proper diacetyl level for style in his/her beer. What causes them and how are they controlled. Are they ever not required and if so, in what beer styles. Address the following topics:

3 points: Describe each characteristic.

4 points: Identify the causes and controls for each characteristic.

3 points: Identify appropriate/inappropriate styles.

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BJCP EXAM QUESTIONSTroubleshooting

T3. What are body and mouthfeel? Explain how the brewer controls body and mouthfeel in his/her beer. Cover the following topics:

5 points: Describe each characteristic.

5 points: Identify the causes and controls for both.

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BJCP EXAM QUESTIONSThe Brewing Process

T11. Describe and explain the role of diastatic and proteolytic enzymes in the brewing process and how they affect the characteristics of the finished beer. Address the following topics:

5 points: Describe what they are.

5 points: Describe how the affect the finished beer.

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BJCP EXAM QUESTIONSThe Brewing Process

T13. Explain what happens during the mashing process, including times and temperatures as appropriate. Describe three different mashing techniques and the advantages and disadvantages of each. Address the following topics:

5 points: Describe the process.

3 points: Identify three techniques.

2 points: Identify advantages and disadvantages of each.

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BJCP EXAM QUESTIONSThe Brewing Process

T14. Provide a complete ALL-GRAIN recipe for a “STYLE,”* listing ingredients and their quantities, procedure, and carbonation. Give volume, as well as original and final gravities. Explain how the recipe fits the style's characteristics for aroma, flavor, appearance, mouthfeel, and other significant aspects of the style.

*Styles may include:

Belgian Tripel Oktoberfest

Classic American PilsnerDoppelbock American IPA

Bohemian Pilsner Robust Porter Weizen

German Pilsner Dry Stout English Pale Ale

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Any Questions?

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