Friday, July 16, 2010

Brewing Glossary of Terms

So it was brought to my attention that not everyone reading this has a strong background in brewing and it may be helpful to have an area where someone can look up a term. I will oblige this, so here is a glossary of terms in alphabetic order. 


acetaldehyde flavor
Green apple-like aroma; by-product of fermentation.

acidic flavor
Pungent aroma, sharp taste. Can be like vinegar (acetic) or lemony (citric or lactic acid). Often the result of bacterial contamination or the use of citric acid. Sensation experienced on the sides of the tongue. Also known as sour flavor.

acid rest
A stage of the mashing process that allows the enzyme phytase to convert phytic acid to phosphoric acid to acidify the mash. During this rest the mash is held at about 95° F (35° C). Lowers the pH of the mash, but also increases the mineral content and producing more accessible sources of nutrients for the yeast.

Any grain added to barley malt for beer making, especially rice, corn, unmalted wheat and unmalted barley. These adjuncts must be gelatinized before mashing. They must be used with a high diastatic powered barley malt to insure diastatic enzymes.

To saturate with atmospheric air or oxygen into solution.

American Homebrewers Association.

alcohol by volume
A measurement of the alcohol content of a solution in terms of the percentage volume of alcohol per volume of water or beer. To approximately calculate the volumetric alcohol content, subtract the terminal gravity from the original gravity and divide the result by 7.5. Abbrev: v/v.

alcohol by weight
A measurement of the alcohol content of a solution in terms of the percentage weight of alcohol per volume of water or beer. The percent of alcohol by weight figure is approximately 20% lower than the "by volume" figure because alcohol weighs less than its equivalent volume of water. Abbrev: w/v. 

Any beer produced with top-fermenting or ale yeast.

all-grain beer
A beer made entirely from malt as opposed to one made from malt extract, or from malt extract and malted barley.

alpha acid
The bitter component of hops that can be made soluble when isomerized by boiling. Given in percentage of alpha acid, which may be used to estimate the amount of bitterness in beer. See HBU and IBU.

An enzyme that breaks down starch into smaller molecules by splitting the chains from the center. It produces glucose, maltose, maltotriose, maltotetraose and long dextrin chains. Until these longer chains are broken into one to three molecule long glucose chains they are not fermentable. This process is called liquefaction or dextrinization. Alpha amylase is most active at temperatures between 131-158 °F (55-70 °C).

alt or altbier
German type of beer made from top fermenting yeast.

ambient temperature
The surrounding temperature.

astringent flavor
Drying, puckering (like chewing on a grape skin) feeling often associated with sourness. Tannin. Most often derived from boiling grains, long mashes, oversparging or sparging with alkaline water.

Reduction of the extract density by fermentation in finished beer. Apparent attenuation can be claculated by subtracting the difference between the original gravity and the final gravity. Real attenuation can be estimated by multiplying the apparent attenuation by 0.816.

Self-digestion and disintegration of yeast cells in nutrient-depleted solutions. This can impart "soapy" off-flavors if beer is allowed to sit too long on the dead yeast. 


A group of unicellular microorganisms lacking chlorophyll and reproducing rapidly by simple fission. Are known to be responsible for the spoilage and contamination of beer. There are no known pathogenic bacteria that can grow in beer.

A cereal of the genus Hordeum, a member of the Gramineae or grass family of plants that also includes wheat, rye, oats, maize, rice, millet and sorghum. There are two varieties (2-row, 6-row) classified according to the number of rows of seeds on each of the heads of the plant. When malted, barley is the cereal grain preferred for brewing because the seed is covered by a husk that protects the germ during malting and helps to filter the wort during lautering by forming a filter bed. The essential qualities for brewing barley are high starch content, sufficient diastatic power to transform the starch into sugar, and low protein content.

Standard unit in commercial brewing. U.S. barrel is 31.5 gallons; British barrel is 43.2 U.S. gallons. Abbreviation; bbl.

An enzyme that bleaks down starches into smaller chains by chopping off maltose molecules from the end. This process is called saccharification because it produces fermentable sugars. Beta-amylase is most active at temperatures between 113-149 °F (45-65 °C).

Brownish-gray, calcium oxalate and organic deposits left on fermentation equipment.

A desirable flavor quality created by the isohumulones of hops. See HBU and IBM.

A quality of beer, largely determined by the presence of colloidal protein complexes. Also partially due to the presence of unfermentable sugars (dextrins) in the finished beer.

The sudden precipitation of proteins and resins in wort. The hot break occurs during the boil, and the cold break occurs during rapid chilling.


campden tablets
Pellets of sodium metabisulphite used as infection-inhibiting agent. Not technically a sterilizer. Used more in wine, mead, and cider making than brewing.

The heat-induced browning of sugars, different from the Maillard reactions in malt kilning.

Tradename for a specially processed malt used to add body to pale beers. Similar to crystal but not roasted. Also called dextrine malt.

A large, narrow-necked glass, plastic or earthenware bottle used to ferment beer or wine. Available in 2, 5, 6.5, and 7-gallon sizes.

chill haze
Haze caused by precipitation of protein-tannin compounds at cold temperatures. Does not affect flavor. Reduce proteins or tannins in brewing.

chocolate (malt)
Medium-brown roasted malt.

cold break
Rapid precipitation of proteins, which occurs when boiled wort is rapidly chilled.

The process of maturation of beer, whether in bottles or in kegs. During this phase, complex sugars are slowly fermented, carbon dioxide is dissolved, and yeast settles out.
The enzymatic transformation of starches into various fermentable and unfermentable sugars that occurs during the mashing process.

cornelius keg
Kegs commonly used in homebrewing. Stainless steel canisters once used for soft drinks. They can be found in 3, 5, and 10 gallon sizes with two types of connector, pin-lock or ball-lock.

corn sugar
Also called dextrose or glucose. A simple sugar sometimes used in beer making, derived from corn.

A procedure used to break grain in to small pieces while maintaining the integrity of the barley husk.

crystal malt
A specially processed type of malt that is used to add body and caramel color and flavor to amber and dark beers. Comes in several shades of color (10 - 220° Lovibond) 


To extract by boiling. This continental mashing technique takes the mash through a series of controlled temperature stages by removing a portion of the mash, bringing this mixture to a boil and returning it back to main portion of the mash. Each successive step or decoction is used to raise the temperature of the main mash. This type of mash typically employs two or three decoction steps that correspond to temperature rests employed by other mashing methods. Decoction mashing typically achieves an extremely high rate of extraction and increased amount of malt character. Decoction mashing is a historical method of achieving starch conversion before the existence of the thermometer.

diacetyl flavor
Described as buttery or butterscotch. Sometimes caused by abbreviated fermentation, mutated yeast or bacteria. Also known as buttery flavor.

The term used to refer to all enzymes in barley and malt involved in the conversion of starch to sugar during mashing.

DMS flavor
Dimethyl sulfide. A sweet corn-like aroma. Can be attributed to malt, short, covered or non-vigorous boiling of the wort, slow wort chilling, or in extreme cases, bacterial contamination.

The gradual addition of water to crushed malt to create a uniformly moistened grain and water solution. Doughing-in is used to prevent the formation of dry spots in the mash.

draft, draught
Beer from a cask or a keg, as opposed to bottled beer. Draft beer stored (usually under pressure) in metal kegs is often non-pasteurized and minimally or not filtered.

A method of adding hops directly to the secondary, to increase hop aroma without adding bitterness.

German word for "dark," as in dark beer. Usually refers to Munich dark style.


The yield of fermentable sugar from the mash. This can be measured directly as degrees of specific gravity per gallon of wort, or as an absolute percentage of dry grain weight.
essential oil
The aromatic volatile liquid of the hop.

estery flavor
Similar to banana, pear, raspberry, apple or strawberry flavor, may include other fruits. Often accentuated by high fermentation temperatures and certain yeast strains. Also known as fruity flavor.

The two carbon alcohol found in beer.

Term used to refer to sugars derived from malt. Also, the commercially prepared syrups or dried products.


A thermometer scale in which the freezing point of water is 32° and the boiling point is 212°. Abbreviated °F.
To convert °Fahrenheit to °Celsius: °C=(°F - 32) x 5/9
To convert °Celsius to °Fahrenheit: °F=(°C x 9/5) + 32

false bottom
A perforated plate or screen set above the bottom of the lauter/mash tun to separate grain from the mash liquor. Aids in filtering back the grain during siphoning and sparging.

The chemical conversion of fermentable sugars in the wort into ethyl alcohol and carbon dioxide gas, by yeast, resulting in a drop in the specific gravity of the beer as the alcohol content increases.  

A generic name for any open or closed vessel in which fermentation takes place.

A procedure used by brewers to clarify beer with the use of gelatin, Irish moss or isingglass.

Grains that have been moistened and pressed or rolled into flakes. Flaked grains are gelatinized during the flaking process and can be added directly to the mash.

The formation of clumps or masses. Usually referring to yeast in later stages of fermentation. Can also be used referring to proteins in a cold or hot break.

The head on the surface of beer or fermenting wort

fusel alcohol
Higher, more complex alcohols, found in all fermented beverages.


Used in beermaking as a fining agent. See Fining.

grain bed
The grain bed is formed by the collection of grist particles and grain husks on top of the false bottom of the lauter/mash tun. Once established the grain bed allows for the separation of the clear wort from the spent grains during sparging.
grain bill
The list of grains and their amounts used for a particular recipe.

Specific gravity. Density of a solution as compared to water; expressed in grams per milliliter. One milliliter of water weighs one gram. S.G.=1.000.

A container (as a jug or pitcher) for beer bought by the measure.

A medieval herb mixture used in beer.

A Belgian ale, uniquely fermented with wild yeasts. Final product is made by blending old and young beers.


Foam on the surface of beer or fermenting wort.

German word for "light," denoting a pale Munich syle.
Heat Exchange Recirculating Mash System. A variant of the RIMS. With this mashing method the temperature of the mash is changed by applying heat via a heat exchanger instead of the mash liquor itself. This produces greater temperature control and eliminates scorching of the mash liquor. Like the RIMS this system employs constant circulation of the mash liquor and the multiple temperature steps like acid rest, protein rest, saccharification rest and mash out, giving greater control over the mash schedule.

A perennial climbing vine, also known by the Latin botanical name of Humulus lupulus, a member of the natural family of Cannabinaceae. Only the female ripened flower is used to give beer its bitterness and characteristic aroma.

hop back
A strainer tank used in commercial brewing to filter hops and trub from boiled wort before it is chilled.

hop schedule
Adding hops to the boil at different intervals producing complex hop bitterness, aromas and flavors.

hot break
The rapid coagulation of proteins and resins, assisted by the hops, which occurs after a sustained period of boiling.

hot liquor tank
The vessel used to hold the hot water used for brewing steps, like sparging.

One of the most plentiful of the many oils which give hops their characteristic aroma.

A glass instrument for measuring the specific gravity of liquids as compared to that of water, consisting of a graduated stem resting on a weighted float. Most hydrometers are calibrated for use at 15.6°C (60°F) and tables or charts are provided listing corrections for variations in temperature. The accuracy of a hydrometer is tested in water at 15.6°C (60°F) where it should read 1.000.


International Bittering Unit. The accepted method of expressing hop bitterness in beer. PPM of dissolved iso-alpha acids present in beer. 

infusion mash
A single-step single-temperature method employed to mash highly modified malt. During an infusion mash the temperature of the mash is maintained between 150 and 158 °F 1(66 and 70 °C) for one half to one hour for the saccharification rest. This mash technique of the simplest type used to make ales and stouts.

The introduction of a microbe into surroundings capable of supporting its growth. See pitching.

iodine test
A procedure used to determine whether starch conversion has been completed. An iodine solution turns dark blue or black in the presence of unconverted starch. Total saccharification causes no change in the color of the iodine.

irish moss
A marine algae, Chrondus crispus, that is used during wort boiling to enhance the hot break. Also known as carrageen.

A type of gelatin obtained from the swim bladder of certain types of fish (usually sturgeon), used as a fining agent in ales.

The structural chemical change that takes place in hop bittering resin (alpha-acids) which allows them to become soluble in wort during boiling.


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The boiling vessel, also known as a copper.

The process of drying germinated barley. Kilning terminates the germination process and roasts the grain. The degree of kilning determines the final characteristics of the malt being produced. The lowest temperature and duration kilnings provide a light straw-colored malt. Higher temperatures and longer kilning produce specialty malts like roast, chocolate or black patent.

A style of ale made in the city of Koln (Cologne).
The period of fermentation characterized by a rich foam head.

The practice of adding vigorously fermenting young beer to beer in the secondary.

Cherry, usually referring to a cherry Belgian lambic ale.


lactic acid
An organic acid sometimes used to assist the acidification of the mash. Also, a by-product of Lactobacillus.

Large class of aerobic bacteria. May be either a spoilage organism, or a consciously added fermenting agent in Kolsch, or Berliner weisse.

"To store." A long, cold period of subdued fermentation and sedimentation to active (primary) fermentation. Any beer produced with bottom-fermenting or lager yeast.

A highly distinctive wheat ale made in Belgium. Brewed with wild yeast and beer souring bacteria. Lambics have a sharp, tart taste, and usually flavored with fruit.

The thin mash after saccharification; the sweet mash liquor.

lauter tun
A vessel used to separate spent grains or draff from the lauter. This vessel is typically fitted with a false bottom that holds the grain bed during sparging. Also called the sparging vessel.

A standard scale for the measurement of grain wort and beer color. A particular sample is characterized with a Lovibond rating by comparing it to a standard liquid reference sample. Malt is as signed a Lovibond rating by producing a sample wort from a single malt grist and comparing the result to the standard color reference samples. Expressed in &degLovibond.

The resiny substance in hops containing all the resins and aromatic oils.


maillard reactions
Complex chemical reactions of carbohydrates and amino acids which occur during the roasting of malt. Responsible for the production of melanoidins and many different roasted flavors. Also called maillard browning.

Barley that has been processed for the purpose of converting the insoluble starch to the soluble substances and sugars. Three factors determine the quality of malt: 1-its protein content must be as low as possible, 2-its starch content must be as high as possible, 3-its germinative power must be superior.

The process of converting barley into malt. The process is divided into three stages: 1-steeping the barley in water until a designated moisture content has been reached, 2-germinating the wet barley under controlled conditions, 3-kilning the germinated barley (green malt) to dry it and/or roast it.

malt extract
Concentrated preparations of wort. Available as syrup or powder, in a wide range of colors, hopped or unhopped.

Purified long-chain unfermentable sugar (dextrin). Used as an additive in extract beers, to add body. Isomaltose, amylodextrin
Type of German lager brewed in March for consumption during Oktoberfest. Slightly darker and stronger than standard pale lager.

The process of enzymatically extracting and converting malt solubles to wort. Mashing involves combining crushed malt grain and water at various temperatures to induce enzymatic activities.

mash out
The final stage of decoction and step mashing. During the mash out the mash temperature is raised to 168 °F (76 °C) and allowed to rest for five minutes. This procedure is used to terminate enzymatic activity and to improve the flow of the sugar solution during lautering.

mash tun
A vessel used to hold the grain and water mixture during the mashing process. Mash tuns come in a variety of styles to accommodate various mashing methods. Usually fitted with false bottoms allow for use as combination mash/lauter tuns.

Wine made from honey, sometimes with the addition of malt, fruit, spices, etc.

Group of complex color compounds formed by heating sugars and starches in the presence of proteins. Created in brewing during grain roasting and wort boiling.

Sensory qualities of a beverage other than flavor, such as body and carbonation.


nitrogen gas
Used to pressurize stouts to give a rich creamy head.

oast house
Facility where hops are dried and processed.

1-A beer festival held annually in M√ľnich's Theresienwiese (Theresa's Meadow) for sixteen days and nights in late September and early October. The festival originated with the wedding festivities of the Bavarian heir prince Ludwig to the princess Theresa in 1810. 2-A bottom-fermented Vienna- or Marzen-style beer originally brewed especially for the Oktoberfest but now available year round.

original gravity (OG)
Specific gravity of wort before fermentation has started.

Chemical reaction that occurs between oxygen and various components in beer resulting off-flavor.

oxidized flavor
Develops in the presence of oxygen as the beer ages or is exposed to high temperatures; winey, wet cardboard, papery, rotten vegetable, pineapple, sherry, baby diapers. Often coupled with an increase in sour, harsh, or astringent taste. Also known as stale flavor.


Antiquated brewhouse practice in England. First and strongest runnings become strong ale, second runnings become ordinary beer, and the last and weakest runnings become small beer. Useful technique for no sparge mashing where the last runnings is used for yeast starters.

The process of sterilizing by heat.

A chain of galacturonic acid that becomes gelatinous in the presence of sugars and acids.

A numerical measurement of acidity or alkalinity determined by the presence of hydrogen ions. The pH scale ranges in values from one to 14 with seven being neutral. A pH of lower than seven indicates acidity or the presence of more hydrogen ions. The lower the pH number, the higher the concentration of hydrogen ions and the stronger the acidity of the solution. Numbers above seven represent alkalinity with 14 representing the strongest alkali solution.

pH meter
An instrument with a digital display that measures, calculates and displays the pH of a solution. This device must be calibrated with a solution of known pH. A properly calibrated pH meter is more accurate than pH paper because visual comparison of color is not required.

pH paper
Chemically treated strips used to measure the pH of a solution. The strips change color in response to the acidity or alkalinity of a solution. The degree of color on the strip is compared to a standard scale to determine the level of acidity or alkalinity.

Aromatic hydroxyl precursors of tannins (polyphenols).

phenolic flavor
Can be any one or a combination of medicinal. plastic, electrical fire, Listerine-like, Band-Aid-like, smoky or clovelike aromas and flavors. Most often caused by wild yeast or bacterial contaminations. Can be extracted from grains, sanitizing residues left in brewing equipment can contribute.

Inoculating wort with a yeast starter to begin fermentation.

European and American scale of gravity based on a percentage of pure sugar in the wort. A newer, more accurate version of the Balling scale. Expressed as °Plato.

Polyphenols are derived from the husk and are acidic precursors of tannins. These molecules can give beer an astringent taste. Polyphenol extraction can be reduced by keeping the pH of the mash between 5.0 and 5.5. Polyphenols form complexes with proteins and are the cause of chill haze.

primary fermentation
The first stage of fermentation. Initial rapid stage of yeast activity when the simple sugars in the wort are metabolized.

The process of adding sugar to beer before bottling or racking to kegs. Induces fermentation to carbonate the beer (bottle condition).


To drink a beer heartily.


The transfer of wort or beer from one vessel to another.

A dark German lager beer made from smoked malts.

A German law the title of which signifies "pledge of purity" or "order of purity." This purity law governs the production and quality of beer in Germany. Enacted in 1516 that only water, malted barley, malted wheat and hops could be used to make beer. Yeast was not mentioned but taken for granted. This law is still effective today in Germany and was adopted by some neighboring countries. The German beer law prohibits the use of adjuncts, including sugar.

Any of numerous clear to translucent yellow or brown, solid or semisolid, viscous substances of plant origin, such as lupulin in the hop flower.

Holding the mash at a specific temperature to induce certain enzymatic reactions.
Recirculating Infusion Mash System. A temperature-controlled mash procedure that employs multiple temperature rests and constant circulation of the mash liquor. With this mashing method the temperature of the mash is changed by applying heat to the mash tun to produce the desired temperature increase. Typical steps are acid rest, protein rest, saccharification rest and mash out. Another variant is the HERMS.
Term used to describe a "rocky" like texture of kraeusen, especially during primary fermentation.

Creating turbulence by agitation, stirring or mixing.

The liquid that is separated from the spent grains during lautering or sparging. Also called runnings, wort, sweet wort or sweet liquor.

Scientific genus name of yeast used in brewing. Saccharomyces cerevesiae, which is ale yeast and Saccharmyces uvarum, which is lager yeast.

secondary fermentation
A second fermentation in a second, closed fermenter allowing for a slow reduction or conditioning of the remaining fermentable sugars. The beer is racked off the trub and degenerating yeast cells that can impair the flavor.

A pipe or tube fashioned or deployed in an inverted U shape and filled until atmospheric pressure is sufficient to force a liquid from a reservoir in one end of the tube over a barrier higher than the reservoir and out the other end.

six-row barley
This malt variety has six distinct seed rows on the grain head. Very high diastatic power allows mashing with up to 60% grain adjuncts, great if added diastatic strength is needed in a recipe. Six-Row also has greater husks per weight ratio than two-row. Protein rest recommended to avoid chill-haze.

Faint "skunk" aroma caused by overexposure of beer to light. Light struck.

Process of rinsing mashed grains with hot water to recover all available fermentable sugars. The sparge water is layered in a fine spray on top of the grain bed at about the same rate as the runoff. 

specialty malt
Barley malt with a higher degree of roasting during the kilning process. This creates a range of color and flavor characteristics in the finished malt. Malt characteristics range from pale to black and each style has a particular flavor from mild to a burnt roast. Specialty malts usually do not need to be mashed.

specific gravity
A measurement of density, expressed relative to the density of water. Used in brewing to follow the course of percent attenuation.

Standard Reference Method. A method of measuring color intensity roughly equal to Lovibond degrees, used by the ASBC (American Society of Brewing Chemists). Expressed as 10 times the absorbance of beer, as measured at 346 nm. This system has largely replaced the older Lovibond color rating system in the brewing industry. The Europeans use a unit called EBC "(European Brewery Convention) degree." To convert between the two use these formulas: 1 °SRM = 0.375 °EBC + 0.46 or 1 °EBC = 2.65 °SRM - 1.2.

The small amount of fermenting beer used in pitching. 

The soaking barley or wheat in water to begin germination in the malting process. Steeping barley provides the moisture required for seed growth. The term steeping also refers to the practice of crushing and immersing specialty grains in the brewing kettle prior to producing wort with malt extract.

Type of beer brewed in Germany, using hot stones to boil the wort.

step infusion
A temperature-controlled mash procedure often called a step mash that employs multiple temperature rests. With this mashing method the temperature of the mash is changed by applying heat or introducing hot water to produce the desired temperature increase. Typical steps are acid rest, protein rest, saccharification rest and mash out.

strike temperature
The target temperature of a mash rest, the temperature at which a desired reaction occurs.


Complex polyphenol polymers with a characteristic astringent flavor, extracted from hops and the husks of barley. Tannins react with proteins and contribute to haze formation.

terminal gravity
The density of the fully fermented beer. The final specific gravity.

Coagulated protein and hop resin sludge which precipitates out of wort during boiling and again at chilling.

Sediment or foreign particles stirred up or suspended.

two-row barley
A variety of malt that forms two seed rows along the stem on the grain head. Well modified with a high diastatic power allows mashing with up to 35% grain adjuncts. Because it is fairly neutral two-row makes an excellent base malt and is known as the "workhorse" of many recipes. Greater starch per weight ratio than six-row.  


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Readily vaporized, especially essential oils and higher alcohols.


Term applied to German wheat ales of the Bavarian, or Suddeutsch, style.

German word meaning "white," applied to the tart wheat beers of the Berliner style.

German word for "wheat." Synonymous with weiss.

Device used to separate hops and trub from wort after boiling. Wort is stirred in a circular motion and collects in the center of the whirlpool. Clear wort is drained from the edge.

Belgian word for "white," a type of wheat beer brewed in the north, around Louvain. Often spiced with coriander and Curacao.

The sweet sugar solution obtained by mashing the malt (sweet wort); the hopped sugar solution before pitching (bitter wort).

wort chiller
Heat exchanger used to rapidly cool wort from near boiling to pitching temperature.


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Large class of microscopic fungi, several species of which are used in brewing. The productivity of yeasts in wort varies with the temperature and reaches a maximum at about 86 °F (30 °C). Usually considered to be two major types, ale yeast and lager yeast. Also known as yeastie beasties.


The branch of chemistry that deals with fermentation processes, as in brewing. Also the magizine that the AHA puts out.  



1 comment:

  1. i love how you made a dictionary
    9or an alphabet with what eac letter means) od brewing! i love it!