Glossary of terms from Ales to Zymurgy




A flavorful compound produced during the fermentation process when the yeast digests sugars. At higher concentrations, it may affect a beer’s flavor. At low-concentration rates, it can taste like green apples; at high concentration – latex paint.


Relatively high in acid, slightly tart. Can be refreshing and bright or sour.


The first sprout appearing in the germination of seed. See also Malting Process


A thing added to something else, but secondary in importance or not essential. In beer making, adjuncts such as unmalted corn, rice, oats, wheat, inverted sugar or glucose are used in place of barley malt as additional carbohydrate sources to make a paler and lighter-bodied brew. See also ingredients.


A palate sensation that occurs after the beer has been swallowed.


The action of introducing air or oxygen to the wort (unfermented beer) at various stages of the brewing process. Proper aeration before primary fermentation is vital to yeast health and vigorous fermentation. Aeration after fermentation is complete can result in beer off-flavors, including cardboard or paper aromas due to oxidation.

Alcohol Beverage

Any beverage containing ethyl alcohol, produced by the fermentation of sugars, such as beer, wine or mead, or by the distillation of these products.

Alcohol by Volume/Weight

The percentage of alcohol in a beer or other alcohol beverage. Alcohol by volume is the percentage volume of alcohol in the total volume of the beverage. Alcohol by weight is the percentage weight of the alcohol in the total weight of the beverage. Alcohol by weight is lower than alcohol by volume because alcohol is less dense than water or beer. Four percent alcohol by weight approximately equals 5 percent by volume. As a general rule of thumb, multiply alcohol by volume by 0.8 to get alcohol by weight. Also see ABV/ABW

  1. Probably derived from the Norse “oel,” which originally referred to fermented malt beverages that were not flavored by hops. By that definition, in the earliest times all such beverages would have been ale. When the use of hops as a flavoring agent became prevalent, such hopped brews were identified as beer. Today, beer usually identifies lager – specifically bottom- fermenting brews – and the entire class of malt beverages in general, while the term ale applies only to top-fermented brews.
  2. A beer produced by rapid fermentation at warmer temperatures (65 degrees Fahrenheit) than those used for lagers and with a shorter storage time. These beers are generally darker in color than lagers due to the more heavily roasted malts used in the brewing process. They generally possess a strong hop flavor and may be quite bitter in taste.
  3. The “true ale,” originally brewed in the British Isles, uses an entirely different strain of yeast which, instead of settling, floats to the top of the beer (top-fermenting), is fermented warmer and is not aged.
    See also Ale Styles
Alpha Acid

One of the two major resins in hops. Alpha acid is responsible for most of the bitterness in beer after hops have isomerized in the brew kettle, at which point it is called iso-alpha acid.


A diastatic enzyme produced by malting barley, which converts starch into carbohydrates called dextrins. The dextrins are then converted into fermentable sugars by the enzyme beta-amylase.


A synonym for ethyl alcohol or ethanol, the colorless primary alcohol constituent of beer. Alcohol ranges for beer vary from less than 3.2% to greater than 14% ABV. However, the majority of craft beer styles average around 5.9% ABV.


Relatively high in acid, slightly tart. Can be refreshing Having a high hop content and bitter taste, an “old” ale that originated in northern Germany.and bright or sour.

Amino Acids

Compounds which, when linked together, form protein or are in effect “small proteins” themselves. There are some 50 different known amino acids.

Amylolytic Enzyme

 An organic substance that converts starch into soluble substances, such as sugars

Anaerobic Fermentation

A generic name for any fermentation that takes place without oxygen. In making beer, it occurs after eight to 12 hours of primary fermentation as well as in secondary fermentation, or lagering.

  1. Fragrance, usually in a pleasant sense.
  2. Applied to a beverage, it is the component of the odor that derives from the ingredients of the beverage and flavor-active byproducts of the fermentation process.
Apparent Attenuation

A simple measure of the extent of fermentation that wort has undergone in the process of becoming beer. Using gravity units (GU), Balling (B), or Plato (P) units to express gravity, Apparent attenuation is equal to the original gravity minus the final gravity divided by the original gravity. The result is expressed as a percentage and equals 65% to 80% for most beers.


Of or having an aroma, usually in the sense of being particularly fragrant, sweet or spicy

Aromatic Hops

Refers to hop additions that take place later in the boiling process. Shorter amount of time spent in the boil kettle will provide more aromatic characteristics from the hops rather than bittering characteristics.


A mouthfeel sensation described as contraction or shrinking of tissue in the mouth. To understand astringency, bite a grape stem or banana peel.


In a brewery, the unfermentable extract in wort or beer by a balling measurement (See also balling). For example, a wort sample with an attenuation of 3 degrees balling cannot be fermented to a final extract level any lower than that corresponding to a 3 degrees balling.


A process in which excess yeast cells feed on each other producing a rubbery or vegetal aroma.




The feature of a beer concerned with the balance of various flavors, aromas, tastes and sensations.

Balance Tank

Surge tank before or after a brewing operation, such as a filter, used to stabilize the beer supply into or out of that operation.


A measure of the density of wort or beer. Degrees balling (or °Plato) corresponds to the percentage of sugar in water and is used to measure the extract in wort or in beer. Ballings may be determined by a hydrometer – or balling spindle – which floats in the liquid at a level corresponding to sugar content (See also hydrometer), by a refractometer where a beam of light is deflected in direct proportion to the amount of sugar or by numerous methods of modern instrumentation that measure density.


A cereal grass with bearded spikes of flowers as its seed or grain. Barley is the most suitable cereal grain for making malt beverages. It provides starch, enzymes, flavor, foam, body and color. See also Ingredients.

Barley Wine

A strongly flavored ale that dates back to the ancient Egyptians. Today’s barley wine remains strong in flavor and alcohol (often 8 to 14 percent), assertive of both sweetness and bitterness in the nose and the mouth.

  1. A wooden cylindrical container with flat ends and sides that bulge outward, usually made of wooden staves bound with metal bands.
  2. Traditional measure of beer volume equal to 31 U.S. gallons.
Batch Fermentation

The most common, traditional method of fermentation used to produce alcohol beverages where each batch is fermented separately.


Any beverage containing ethyl alcohol, produced by the fermentation of sugars, such as beer, wine or mead, or by the distillation of these products.Beer The generic name for alcohol beverages made when yeast ferments extracts from cereal grains and other starchy materials. Known to the Egyptians, Babylonians and probably earlier civilizations, beer became the common beverage in Northern climates not conducive to grape cultivation. Although beer and wines are both fermented and undistilled, wine is made from basic materials rich in natural sugar, while beer is made from materials high in starch content. These starches must be converted to sugar before fermentation can occur.

Beer Stone

Grayish-brown deposit formed from calcium and fermentation byproducts on the surface of equipment in prolonged contact with beer.

  1. That typical of beer.
  2. As an aroma, one that is generally yeasty and malty, but having a noticeable level of hops.
Beta Acid

One of the two major resins in hops. Beta acids contribute very little to the bitterness of beer.


A diastatic enzyme produced by malting barley to convert dextrins and soluble starches into fermentable sugars.


A small vessel traditionally used to measure the amount of yeast to be proportioned into the wort for the proper pitching rate.

Biochemical Pathway

A sequence of chemical reactions, each of which is catalyzed by an enzyme supplied by microorganisms. Brewing takes advantage of biochemical pathways.

Birch Beer

A non-alcohol, usually carbonated beverage flavored with oils of wintergreen, sweet birch or sassafras.


The tangy, basic taste in beer that results from hops. Without the bitterness, a beer has no zest. With too much bitterness, a beer is hard and biting.

Black Malt
Partly malted barley of moderate nitrogen content (1.5 percent) that is germinated for four to six days, kiln-dried down to 2 to 5 percent moisture, then roasted in a coke or gas-heated rotating drum at a high temperature (450o Fahrenheit) for two to two-and-one-half hours. It is used in small amounts in stouts and dark beers to which it contributes a burnt or caramelized flavor. Since it contains no fermentable sugar, all the
Bock Beer
  1. A very strong beer originally brewed by top fermentation in the Hanseatic town of Eiubeck in Lower Saxon, where it is still brewed and known as Ur-Bock, the original bock.
  2. A dark lager type of beer using caramelized or burnt malt for color, usually with more body than typical lighter lager beers. Traditionally brewed in the spring, bock beer has sometimes been associated with Sagittarius since bock is German for “goat.” German bock beers are now brewed by bottom fermentation and are usually dark brown. See also  beer styles.

The mouth-filling property of a beer. Taken to the extreme, stout has a heavy or full body; pale low calorie beer may be thin or watery.


Beer aged in the bottle.

Bottom Fermentation

One of the two basic methods of fermentation for beer, characterized by the fact that dormant yeast cells sink to the bottom during the process. Beers brewed in this fashion are commonly called lagers, or bottom-fermented beers.


That portion of the aroma caused by byproducts of the fermentation process.


Reddish-brown deposits of yeast, hop resins and proteins on the top and sides of fermentation vessels above the beer level.


The coagulation and precipitation of protein and tannin matter during the boiling stage (hot break) and cooling stage (cold break) in wort.

Brewer’s Yeast

Yeast specifically prepared for brewing beer. Two main types of yeast are used: one ferments at the top of the brew and the other ferments at the bottom. Brewer’s yeast may be gathered from the previous brew or purchased in dry or liquid form. See also ingredients.

Brewer’s Grains

Synonym for spent grains. See also spent grains.


The section of a brewery where the actual brewing – or mashing – takes place.

Brew Kettle

A large vessel, similar in shape to a mash tank or tun, made of copper or stainless steel, in which the wort is heated for one to two hours by steam coils, calandria or through a jacketed bottom.


A refrigerated yeast storage tank for holding the yeast prior to its use in pitching.


The most common form of yeast cell reproduction. The cell increases in size, forming a rounded outgrowth that eventually separates into a daughter cell. See also volume ii: ingredients.


A palate sensation of butter or butterscotch, caused by the presence of diacetyl, a natural fermentation byproduct. While acceptable in certain ale styles, diacetyl is considered an indicator of immature beer. Lagering reduces it to very low levels.



  1. Measure of energy required to do work. One calorie equals the heat required to raise one kilogram of water by 1 degree Celsius.
  2. Human-body intake and energy expenditure are measured in calories. A 12- ounce portion of regular beer has approximately 150 calories. Light beers generally contain 100 calories.
Caramel Malt

Malt prepared from fully modified sugar-rich barley that is lightly steeped, kiln-dried, resteeped and heat-dried again at temperatures of 150 to 170 degrees Fahrenheit for one to two hours, thus converting the soluble starches within the grain into sugar as in mashing. The temperature is then increased to about 250 degrees Fahrenheit. Caramel malt is available in pale (cara-pils) to dark colors and is used in small amounts (5 to 15 percent) to impart sweetness, aroma and a coppery color to beer. See also Malts


To turn into caramel; a burnt sugar.

  1. Any one of a group of compounds made up of carbon, hydrogen and oxygen that has two atoms of hydrogen for every atom of oxygen. Carbohydrates include sugars, starches and celluloses.
  2. Carbohydrates in finished beer are predominantly those unfermentable substances from the wort.
Carbon Dioxide (CO2)

Arising from the yeast during fermentation, a natural, inert gas that gives beer its bubbles.

  1. Carbon dioxide dissolved in the beer. When saturated, carbon dioxide gas will be released if the temperature is increased or the pressure reduced.
Cast or Knockout Wort

 Boiled wort. 

  1. Brand name of diatomaceous earth, a substance used in filtering.
Cereal Cooker

A vessel in which cereal adjuncts (wheat, rye, oats or corn) boil prior to their addition to the mash.


Spanish for beer.

Chill Haze

Cloudiness caused by a combination and precipitation of protein matter and tannin molecules during secondary fermentation. It becomes visible when beer is refrigerated too fast, too cold or too long. It soon disappears once the beer warms up.

  1. A treatment applied to finished beer to prevent the formation of chill haze.
  2. To stabilize or eliminate protein compounds to maintain beer clarity.

Taste and smell reminiscent of fermented apples or citrus fruits.

  1. Acronym for “clean in place.”
  2. A system of automatic cleaning, using high-velocity flows of caustic solution through lines and vessels, followed by a clean water rinse.

The process of removing suspended particles from the cloudy wort or the finished beer through mechanical (filtration, centrifugation) or chemical means (by adding proteolytic or pectolytic enzymes or flocculating agents).


To clear of particulate matter, either naturally with settling or through filtration or finishing.


The degree to which the beer has no particulate matter in its solution, ranging from clear to cloudy.

  1. Too sweet or rich.
  2. An intense, thick sweetness.
Cold Break

The coagulation of protein and tannin material during the wort cooling stage. It starts around 140 degrees Fahrenheit and increases as the temperature drops. 


The hue or shade of a beer, primarily derived from grains, sometimes derived from fruit or other ingredients in beer. Beer styles made with caramelized, toasted or roasted malts or grains will exhibit increasingly darker colors. The color of a beer may often, but not always, allow the consumer to anticipate how a beer might taste. It’s important to note that beer color does not equate to alcohol level, mouthfeel or calories in beer.  See also Color

Contract Brewing Company

A business that hires another brewery to produce some or all of its beer. The contract brewing company handles marketing, sales and distribution of its beer, while generally leaving the brewing and packaging to its producer-brewery.


The process of lowering the temperature of boiled wort prior to fermentation. In top fermentation, the wort is cooled to 55 to 60 degrees Fahrenheit. In bottom fermentation, it is cooler, often 40 to 45 degrees Fahrenheit.


Draught beer containers. (See also kegs.)

Cream Ale

A blend of top- and bottom-fermented beers, usually more of the latter, resulting in a sweet and lightly hop-flavored drink. See also volume iv: beer styles.



Dark Beer
  1. A general name for dark-colored beers that resemble the hue of caramelized or roasted malt. The ingredient licorice is partly responsible for the blackish color of some beers, such as porter.
Decoction Mashing

One of three brewing methods and the one used for bottom-fermenting beers. The process requires three vessels: a mash tank or tun for mash mixing, a mash kettle (or copper or mash copper) for boiling and a lauter tun (or clarifying tun) for straining. Mashing takes place in a mash tun and starts at a low temperature while portions of the mash are taken out and boiled in the mash kettle and later returned to the mash tun.


A complex, unfermentable carbohydrate produced by the partial hydrolysis of starch through the action of alpha-amylases during mashing. Dextrins contribute to the final gravity and body of beer. Some dextrins remain undissolved in the finished beer, giving it a malty sweetness and round body. See also Sugars

  1. A crystalline sugar found in plants and animals.
  2. In beer, a substance produced from starch during the conversion of barley into malt.
Diatomaceous Earth (DE)

Deposits created by the skeletons of plankton-like marine algae, which are mined for many useful purposes, in addition to serving as the primary filtration media in brewing and in many other industries. The substance also appears in face powders and serves as a mild abrasive in toothpastes.

Dimethyl Sulfide (DMS)
  1. At low levels, DMS can impart a favorable sweet aroma in beer. At higher levels DMS can impart a characteristic aroma and taste of cooked vegetables, such as cooked corn or celery. Low levels are acceptable in and characteristic of some Lager beer styles.


In Germany, a beer much stronger than a simple bock, but not necessarily doubly so. See also Styles


A style of lager beer much the same as Pilsner, developed in Dortmund, Germany.  See also Styles

Draught (or Draft)
  1. Beer drawn from kegs, casks or serving tanks rather than from cans, bottles or other packages.

  2. Beer consumed from a growler relatively soon after filling is also sometimes considered draught beer.

  3. The act of drawing beer from a keg.

Not sweet. A beer that has little to no residual sugars.

Dry Beer
  1. Beer with a more or less pronounced “dry” taste. These beers are usually brewed like other beers, but with a higher degree of fermentation, resulting in a slightly lower calorie and alcohol content in the finished product.
Dry Hopping

The addition of loose, dry hops to the primary fermentor (after the wort has cooled to below 75 degrees Fahrenheit) or to the secondary fermentor to increase the aroma and hop character of the finished beer without affecting its bitterness.




A bubbling up or foaming as gas escapes. 


The starch-containing sac of the barley grain. The endosperm constitutes 80 to 85 percent of the dry weight of the grain. Part of this starch serves as a food reserve for the growing embryo, while the remainder constitutes the bulk of the extract during mashing.


Naturally occurring, complex compounds. When in solution, enzymes produce chemical changes in other compounds without resulting in changes to the enzyme itself. Enzymes are sensitive to heat and undergo deactivation at about 112 to 140 degrees Fahrenheit.

Essential Oil

A volatile, aromatic, oily compound found in plants, especially hops.


Volatile flavor compounds, which form during fermentation through the interaction of organic acids with alcohols. These contribute to the fruity aroma and flavor of beer. 


Also known as ethyl alcohol, one of many compounds classified as alcohol, but synonymous with the common definition of alcohol as contained in beer.

  1. Any beer produced for the express purpose of exportation. For example: export-style German lagers or export-style Irish stouts.




One of the essential oils made in the flowering cone of the hops plant Humulus lupulus. See also Hops


In malt beverages, it is the decomposition of sugar into ethyl alcohol, carbon dioxide and other flavor compounds by the yeast. See also esters.


The vessel in which primary fermentation takes place.


The passage of a liquid through a permeable or porous substance to remove solid matter in suspension.


Fining A process of speeding up the clarification of a malt beverage (or wine). Fining usually involves the addition of fining agents, such as isinglass, enzymes, gelatin (all coagulants) or bentonite or cellulose (mechanical fining agents). See Ingredients-Finings

Fire Brewing

A traditional brewing method using direct fire to heat the brew kettle rather than steam or hot water, thus producing heavier caramelization on the direct-fired surface.

First Wort
  1. The clarified extract strained from the mash to the brew kettle prior to sparging.
  2. The first runnings of wort to be filtered in the straining vessel. It is richer in extract than subsequent runnings. 

Beer lacking in amplitude and lift because it has little or no effervescence. 


The qualities of a substance that give it its characteristic taste.  See Flavors & Flavoring


The phenomenon by which yeast cells aggregate into masses toward the end of the fermentation cycle and drop. Certain yeast cells sink to the bottom of the fermentor, thus contributing to the clarification of the beer. The ability of yeast (either top- or bottom-fermenting) to flocculate varies with the strain of yeast.

  1. Device used to moisten milled malt before it enters the mash vessel. Foremashing helps prevent light material from floating on top of the mash.


Quality in a beer that is rich and mouth filling as opposed to one that is thin-bodied and watery.




A liquid measure equaling four quarts, 128 ounces or 3.785 liters.


To bring starches to a soluble state for conversion during mashing.


Beginning of vegetation or growth in seeds. The malting process for barley is designed to begin the germination process, then stop it at a critical time to allow brewers to use the plants’ natural starches in the production of beer.  See Malting Process


Small vessel between the straining tank (tun) and the brew kettle from which the runoff of the wort is controlled and sampled.


Grist or “ground grist” refers to malt and cereal that is ground (milled) in the brewhouse by a malt mill at the beginning of the brewing process.  See Malting Process

Green Beer

Young or immature beer, fresh from its first fermentation, before it has undergone lagering.


An old-fashioned herb mixture used for bittering and flavoring beer, popular before the extensive use of hops. Gruit or grut ale may also refer to the beverage produced using gruit.


Calcium sulfate, a naturally occurring calcium compound found in the earth and mined for a variety of uses. Often used in brewing to increase calcium in water for yeast nutrition and for increased beer stability.



Hand Pump

A device for dispensing cask conditioned draught beer using a pump operated by hand. The use of a hand pump allows the draught beer to be served without the use of pressurized carbon dioxide.


Often referred to as “last hansel,” the final spargings, or measurement of extract remaining in the wort going to the brew kettle at the conclusion of straining.

Head Retention

The foam stability of a beer as measured, in seconds, by time required for a 1-inch foam collar to collapse.


Refers to the common practice of brewing and fermenting a concentrated brewhouse wort and adjusting this beer to its final “gravity” or composition at the end of the process. High-gravity brewing permits better use of equipment, can increase the capacity of a brewery and helps maintain better consistency of the strength of the final product.


The dried, ripe cones of the female flowers of a climbing-vine member of the nettle family. The resin from the cones is used for aromatic flavoring, bittering and preserving beer.  See Ingredients-Hops

Hot Break

The coagulation of protein matter from the wort during boiling in the brew kettle.


Synonym for alpha acid, one of the two major resins found in hops. It is composed of humulone, cohumulone and adhumulone. See Ingredients-Hops.


A glass instrument for measuring the specific gravity of liquids as compared to that of water. Hydrometers consist of a graduated stern resting on a weighted float.



Ice Beer

A device for dispensing cask conditioned draught beer using a pump operated by hand. The use of a hand pump allows the draught beer to be served without the use of pressurized carbon dioxide.

Immobilized Yeast

Yeast attached to support materials within fermenters reactors. This yeast mostly remains in place during fermentation and allows a clearer beer to be produced. It is also more active in its metabolism but is mostly used to mature beer rather than primary fermentation.

Imperial Gallon

A capacity measure in the United Kingdom and the Commonwealth equivalent to 1.2 U.S. gallons or 4 liters.

India Pale Ale or IPA

An ale of the type produced for British troops serving in India during the last century. It was produced strong and dry-hopped so it could survive the long passage to India, which took more than six months and involved equatorial crossings. See Beer styles.

Infusion mashing

A traditional mashing process involving keeping the mash at a single temperature during the mash period. This is typically between 60 and 70oC where amylase activity is maximal. Infusion mashes are usually employed for UK beers produced using well modified malt which has incurred extensive protein and b glucan digestion during malting.

International Bitterness Units or IBU

The measure of the bitterness of beer expressed as milligrams of isomerized alpha acid per liter of beer. This measurement depends on the style of beer. Light domestic lagers typically have an IBU rating between 5-10 India Pale Ales can have IBU ratings between 50 and 70.

Iodine Test

Test used in brewing to check conversion of the mash. A drop of iodine is added to a small sample of mash. The sample turns dark blue if unconverted starch remains; it remains unchanged if completely converted.






A sealed cylindrical container constructed of steel or aluminum used to store, transport and serve beer under pressure. In the U.S., kegs are referred to by the portion of a barrel they represent, for example, a ½ barrel keg = 15.5 gal. Other standard keg sizes are found in other countries.

Kettle Break

Formation of coagulated protein and hop compounds during boiling in the brew kettle.


An inert material used to enhance filtration of beer by producing a finely porous cake on a filter membrane. This cake increases in depth as beer is progressively filtered and particles remain entrapped in the cake allowing clear beer to filter through. Keiselguhr is made from the shells of diatoms but other filter aids may be composed of clay or silica hydrogel.


Heat-drying malted barley in a kiln to stop germination and produce a dry, easily milled malt. Kilning also removes the raw flavor associated with germinating barley and develops new aromas, flavors, and colors depending upon the intensity and duration of the kilning process. See Malting Process


To empty the brew kettle.

  1. The rocky head of foam which appears on the surface of the wort during fermentation.
  2. A method of final conditioning in which a small quantity of unfermented wort is added to a fully fermented beer to create secondary fermentation and natural carbonation.
  3. A secondary fermentation whereby young, fermenting wort (approximately 15 to 18 percent) is added to a fully fermented lager to accomplish a natural infusion of carbon dioxide.


Lace Curtain

The lace like pattern of bubble sticking to a glass of beer once it has been partially or totally emptied.


One of the predominant groups of lactic acid bacteria. A number of species including L. brevis, L. delbrueckii and L. pastorianus are contaminants of beer producing lactic acid and other off flavours. Lactic acid bacteria are commonly used in other food fermentations such as yoghurt and sauerkraut.  See Yeast


A generic term for any beer produced by bottom-fermentation yeast, usually by decoction mashing, as opposed to top-fermented beers called ales, usually produced by infusion mashing. Lager brewing was introduced in the 1840s and is now the predominant brewing method worldwide. See Beer Styles.


From the German word lagern, which means “to store.” Lagering, or aging, is a slow extension of the main fermentation to mature beer flavor, usually colder and under carbon dioxide pressure. Lager beers are fermented with a yeast strain, which settles after fermentation (bottom-fermenting or lager yeast). All bottom-fermented beers are considered lagers as they are aged or stored for a period of time at cold temperatures (40 to 50 degrees Fahrenheit) in lager tanks.


A unique Belgian wheat beer produced only southwest of Brussels in a 15-kilometer radius in the area called Pajottenand. Lambic is traditionally brewed in winter – from Oct. 15 to May 15 – because at that time, a microflora develops in the atmosphere of the Senne River valley that is introduced into the beer. In addition, the first few months of fermentation must not be too vigorous. See also volume iv: beer styles.

Lauter Tum

A separating vessel used to sparge a mash and separate clear wort from the residual grains. Differs from a mash tun in being wider with a larger floor area to give a faster run off. Lauter tuns also have stirring rakes to agitate the mash and may be used after the mash has been incubated in a cereal cooker with adjuncts. In this arrangements more mashings may be performed per day so increasing efficiency.


Straining of the mash to separate and clarify the wort. Comes from the German word meaning “clear.”

Light Beer
  1. Beer with a reduced calorie and carbohydrate content. Significant calorie reduction requires some corresponding reduction in the alcohol content as well. Light beers typically contain 90 to 150 calories per bottle
  2. A low-alcohol beer ranging from 2.3 to 3.2 percent alcohol by weight. See Beer Styles.

A beer flavor and aroma defect that results when exposure of beer to ultra-violet or fluorescent light leads to isohumulone in the beer breaking down into 3-methyl-2-butene-1-thiol (3-MBT), a sulfurous compound that imparts a noxious sour aroma to the beer. Sometimes called “Skunking” and the damaged beer is said to be “Skunked”. Depending upon the intensity of the UV source skunking can occur in as little as 20 seconds of exposure.


In the beer brewing industry, “liquor” refers specifically to the water that will be used for mashing and brewing, especially natural or treated water. For all other uses around the brewery, water is simply called “water”.

Low Alcohol Beer

A beer produced from a low gravity wort and incompletely fermented or from a higher alcohol fermentation but with the alcohol removed by evaporation. Generally brewed for a specific market low alcohol beers lack the complex character of standard beers and are often supplemented with malt and hop extracts to provide additional flavor.  See Beer Styles


A spicy flavoured component of hop oil. See Hops




Barley that has been steeped in water to produce sprouting and enzyme production, then kiln-dried. See Ingredients-Malt

Malt Agar

A simple microbiological growth media used in the laboratory for yeasts and moulds. Produced by mixing malt extract with up to 2% agar.

Malt Extract

A thick, sugary syrup or dry powder prepared from malt. Basically, it is a sweet wort reduced to a syrup or powder form by removing most or all of the water by low-vacuum vaporization..  See Ingredients-Malt

Malt Liquor

Lager-type beer which generally has higher alcohol content than regular lager beers. See Beer Styles.


Steeping grain in water, germinating it, and drying it to convert the soluble substances and sugars present in the grain to malt. Barley is the most commonly malted grain but sorghum, rye, wheat and other grains can also be malted. See Malting Process

  1. Malt sugar comprised of two glucose units and produced by the action of enzymes from malt on starch.
  2. Principal source of fermentable extract in brewing. See also dextrose.

In Germany, before the advent of artificial refrigeration, beer was brewed in winter and the last batch, brewed in March, was made especially strong to survive the many months of maturation before it was drunk at the end of the summer. See Beer Styles.


A mixture of ground malt (and possibly other grains or adjuncts) and hot water that forms the sweet wort after straining.

The first major stage in the brewing process where malt and liquor are mixed and left to incubate at set temperature(s). Starch is digested to simple sugars and many compounds are released from the malt to enrich the wort. Infusion mashing maintains a constant temperature, generally between 60 and 68oC while temperature programmed and decoction mashing increases the temperature in steps from 35oC to 45oC to 65 oC and finishing at 75oC to curtain enzyme activity. Temperature programmed mashing is most suitable for poorly modified malt and allows rests at temperatures optimal for the digestion of b glucans, protein and starch respectively.

An alcoholic beverage made of fermented honey, water and sometimes herbs and spices. A distinct beverage, mead is more akin to beer than to wine. See Beer Styles


Darkly pigmented compounds produced by the combination of simple sugars and amino acids. This reaction is accelerated by heating and mostly occurs during boiling. A range of melanoidins is produced from the different sugars and amino acids in the wort and also depends on the time of boiling. Melanoidins are good oxygen scavengers and can protect wort against oxidation and staling.


Distinctive flavor compounds with the aroma of skunk. Produced by the photolysis of a side chain of iso a acids and the subsequent reaction of this with sulphur containing thiol radicals to produce 3-methyl-2-butene-1-thiol. Exposing beer to light, particularly by using clear glass bottles, will initiate this reaction although specially treated hop oil, Tetra hop, will stabilise the iso a acid.


An ironlike flavor in a beer that could be caused by either its container or a flaw in the brewing process. Sometime an overage beer will take on metallic flavors, even in a bottle.

Mild ale

A distinctive British beer with low hop character typically drunk in the north and for some time the dominant ale in England. Traditional versions were brewed with dark malts to give a caramel and liquorice character and a solid body. Current examples are low in gravity and alcohol and some lack the dark malts and are low gravity bitters. ABV is between 3.1 and 4.8%, bitterness around 22 and colour 85 but sometimes up to 200 EBC. A few strong varieties with ABV up to 6.0 are closer to some original milds. See Beer Styles


Milling crushes grains before mashing and so exposes the internal contents to the mash liquor and enhances dissolving and digestion by enzymes. Mills crush grain between two, four or six rollers running in opposite directions and are set to break open the grain but not to crush it into flour. Part crushing is particularly important to ensure that the husk is retained to provide the filter bed for separating wort at the end of mashing. See Malting Process

Millipore Filtration

A type of filtration process sometimes used instead of pasteurization.

  1. The physical and chemical changes occurring in barley during malting. Physically, the grain is rendered millable. Chemically, complex molecules are broken down to simpler, soluble ones by the formation of hydrolytic enzymes, which later begin to break down the starchy endosperm and its cell walls.
  2. The degree to which malt has been converted during the malting process as determined by the extent of the growth of the acrospire.

Taste, fullness, carbonation, bitterness, aftertaste, etc. taken as a whole when drinking a beverage.


A taste flaw that can gives beer aromas and flavors a moldy, mildewy aroma or flavor that can be the result of a bacterial infection in beer.


A bottom-fermented style of beer produced in the mid-19th century in the Bavarian city of Munich. The original Münchener was dark. In 1928, the Paulaner Brewery introduced a paler version, called Helles, that almost has entirely overtaken the darker brew. See Beer styles.



Near Beer

A beer like beverage brewed either to be non alcoholic or to have low-alcohol content from 0.5 percent up to 2 percent. 

Nitrogen (Nitro)
Nitrogen is infused as an alternative to carbonation for beer. Typically indicated by “Nitro” in the beer name. The smaller, insoluble nitrogen bubbles produce a rich, creamy mouthfeel quite different from the mouthfeel from CO2 carbonation. Most nitrogen infused beers are also carbonated with the ratio of nitrogen to CO2 typically around 7:3. Nitrogen comes out of solution very rapidly and “nitro” beers typically go flat in 30 minutes or less.
Noble Hops

Classic European hop varieties prized for their characteristic flavor and aroma of pilsner and other continental lagers. Traditionally these hops are grown only in four small areas in Europe: Hallertau Mittelfrüh in Bavaria, Germany; Saaz in Zatec, Czech Republic; Spalt in Spalter, Germany and Tettnang in the Lake Constance region, Germany.

  1. The total sensation in the nose.
  2. The total effect of the beer’s odor.
  3. The combination of aroma and bouquet.



Building or facility where hops are dried and aged after harvesting.

Original Gravity (OG)
  1. A measure of the total amount of solids dissolved in the wort.
  2. The alcohol content and extract remaining in a beer defines a unique original gravity or OG for that beer. The OG is expressed as the wort balling.
Old ale

A traditional British beer with high alcohol levels and rich and complex flavours. Traditionally dark and well matured, often a seasonal winter brew. ABV is between 4.3 and 12%, bitterness around 29 and colour 70 but sometimes up to 220EBC.


Term used in brewing to express the degradation of beer flavor with time. Warm storage temperatures and the presence of air accelerate oxidation.




The container that holds the beer, either a bottle or can; otherwise, beer is on draught or tap. Packaged beer is usually pasteurized, sterile, filtered or flash pasteurized.

Pale Ale

Building or facility where hops are dried and aged after harvesting. Pale Ale In England, an amber- or copper-colored, top fermented beer brewed with very hard water and pale malts. This is the bottled equivalent of bitters, but drier, hoppier and lighter. The adjective “pale” simply distinguishes it from darker brews, such as brown ale, stout and porter. See Beer Styles.

Particulate Matter

Particles held in suspension in the liquid, such as protein matter, dead yeast cells and grain fragments. 

Pasteurization Unit (PU)

A measure of the lethal effect on organisms during pasteurization. One PU equals one minute of exposure at 140 degrees Fahrenheit.


To subject packaged beer to a temperature of 142 to 145 degrees Fahrenheit for a specified time to destroy enzymes, yeast and other bacteria, thereby prolonging the product’s shelf life.


Measure of the acidity or alkalinity of any liquid. The pH scale of 0 to 14 is used, with 0 to 1 indicating a very strong acid, 13 to 14 a strong alkali and 7 totally neutral.

Pils or Pilsner Beer
  1. A general name for beers that are pale, golden-hued, highly hopped, and bottom-fermented.
  2. The original pilsner was first brewed at the BürgerLiches Brauhaus in the Bohemian town of Pilzen (meaning green meadow) in 1842. It was then the palest beer available and the style was soon copied worldwide. See also volume iv: beer styles.

The addition of yeast to cooled wort. The ideal pitching temperature for top-fermenting yeast is usually 55 to 65 degrees Fahrenheit, whereas that for bottom fermenting yeast is often 40 to 50 degrees Fahrenheit. 

Pitching Rate

The amount of yeast used to ferment a single batch of beer. It is usually expressed in either pounds of yeast per barrel or the numbers of yeast cells per milliliter of wort.

  1. Similar to the balling reading on a spindle (percentage of sugar concentration of a solution), but calculated for 20 degrees Celsius (68 degrees Fahrenheit) instead of 17.5 degrees Celsius (63.5 degrees Fahrenheit). This reading is more accurate than the balling number, although both designations are used interchangeably in a brewery.

A distinctive type of British beer developed as a mixture of different beers. Typically characterised by a balance of malt, roast, hop, bitterness, fruit and spicy flavours. Traditionally with the harsh burnt taste of brown malt many current versions have a full body with roast malt in the aftertaste. ABV is between 3.8 and 6.1%, bitterness around 33 and colour 120 but sometimes up to 300EBC. See Beer Styles

Primary Fermentation

The first stage of fermentation is carried out in open or closed top containers. Active fermenting typically lasts from two to four days and the beer will remain in the primary brewing container for one to four weeks. During this time yeast converts the bulk of the fermentable sugars to ethyl alcohol and carbon dioxide gas. Also called “principal fermentation”; “initial fermentation”.


A law instituted by the 18th Amendment (Volstead Act) on Jan. 18, 1920, forbidding the sale, production, importation and transportation of alcohol beverages in the United States. The 21st Amendment repealed it on Dec. 5, 1933.

Prohibition Era

The 13 years, 10 months and 18 days during which the 18th Amendment remained in force.


Refers to the alcohol content of a beverage. In the United States, proof represents twice the alcohol content as a percentage of volume. Thus, a beer that is 3.2% alcohol by volume is 6.4 proof, a wine that is 14% alcohol by volume is 28 proof, a 100 proof beverage is 50% alcohol by volume, a 150 proof beverage is 75% alcohol by volume, etc.


An organic compound in animal and plant tissues, basically composed of carbon, hydrogen, oxygen, nitrogen and sulfur. All proteins are composed of large configurations of 20 amino acids. Proteins are responsible for the head retention and body of beer, and amino acids are a nutritional source for fermenting yeast.

Proteolytic enzymes
Enzymes found in malt which digest proteins into polypeptides and amino acids. They are very active in malting where much of the barley protein is digested. In poorly modified malt it may be necessary to further digest protein in mashing by a temperature infusion at 50-55oC to avoid beer hazes from excess protein remaining in the wort.
Pub or Public House

A business establishment in Great Britain whose principal wares are malt beverages. 


The hollow indentation at the bottom of some bottles to strengthen the bottle. Also called a “kick up”




To drink deeply, especially an alcoholic drink.

  1. Phenolic compounds produced by the oxidation of polyphenols. Can act as oxidising agents themselves in wort and so produce stale flavours.



Filling of draught beer barrels or cooperage.


A peculiarly distinctive German beer with a rich smoky flavor produced by the use of malt dried over an open fire, peat, and in the smoke of moist beechwood fires. Generally dark in color and bottom fermented. See Beer Styles.


A German law, the title of which signifies “pledge of purity” or “order of purity,” governing the production and quality of beer in Germany. William IV, the Elector of Bavaria, decreed in 1516 that only water, malted barley and hops could be used to make beer. Yeast was not included, but was taken for granted. The use of adjuncts and adjustment water required to brew heavier, gravity beers are considered additives under this law.  See Basics-Reinheitsgebot

Real Ale

A style of ale found primarily in England, where it has been promoted by a consumer rights group called the “Campaign for Real Ale” (CAMRA). Generally defined as ales that have been brewed in the traditional manner with secondary fermentation, if any, taking place in the container from which they are served and that are served without the infusion of external carbon dioxide or nitrogen.


To transfer finished, filtered beer to packaging or racking operations.


The gummy organic substance produced by certain plants and trees. Humulone and lupulone, for example, are bitter resins produced by the hop flower.

Roasted Barley

Unmalted barley that has been kilned to a dark brown color similar to that of chocolate or black malt, but with a different flavor.

Roasted Malt

Malt made from barley heated sequentially, starting at a lower temperature, then raised in increments. The malt acquires a brilliant external appearance, while the endosperm becomes black. Roasted malt is used to flavor and color stout and dark beers.




The natural process through which malt starch is converted into fermentable sugars, mainly maltose.


A form of hydrometer for measuring the amount of sugar in a solution.

Saccharomyces Cerevisiae

Scientific name for top fermenting yeast. Compared to bottom-fermenting yeast, ale yeast ferments more rapidly and has a higher alcohol tolerance. However, it does not convert dextrins (sugars) as well, which means it yields sweeter beers.  See Ingredients-Yeast

Saccharomyces Carlsbergensis

Scientific name for bottom-fermenting yeast. See Ingredients-Yeast

Saccharomyces Uvarum

Scientific name for bottom fermenting yeast.   See Ingredients-Yeast


A traditional Japanese fermented drink made from rice. Contrary to popular belief, saké is neither a spirit (it is not distilled) nor a wine (it is not macerated), but rather a special type of beer brewed from a cereal base. The rice is washed, steamed and fermented with a yeastlike fungus. Primary fermentation takes from 30 to 40 days, after which more rice and water is added to generate a secondary fermentation lasting eight to 10 days with a special saccharomyces yeast. Saké is colorless and slightly hazy, lacks carbonation and is often served warm. See Beer Styles.

Scotch Ale

A top-fermented beer of Scottish origin, but now also produced in Belgium and France with an alcohol content of 7 or 8 percent by volume. Scotch ales are traditionally strong, very dark, thick and creamy. See Beer Styles.

Secondary Fermentation

A second, slower stage of fermentation carried out in closed vessels at 44 to 48 degrees Fahrenheit for about 22 days.


A mixture of beer and lemonade, (lemon-lime soda) popular in England, which is typically lower in alcohol strength.

Silica Gel

A chill proofing agent made from sand, which has the unique ability to remove haze-forming proteins from beer.

Six-Row Barley

A variety of barley having three rows of fertile spikelets at each node on which six rows of grain ultimately form. Because it has a thicker husk and a less-well-developed grain than two-row barley, it yields less extract but normally contains higher enzyme activity.


Like the peculiar aroma of a skunk. The reaction of natural hopped beers when light of certain wavelengths leaves the isoalpha acids, which react to form a mercaptan, with its very strong and peculiar aroma.


The spoiling of beer caused by bacteria contamination.

Sparge Water

The fine spray of hot water used for sparging.


In lautering, an operation consisting of spraying the spent grains in the mash with hot water to retrieve the liquid malt sugar remaining in the grain husks. To prevent the mash from packing, the sparging volume of water must equal the volume of wort coming out the base of the mash tun, thus maintaining a constant level.

Specific Gravity

A measurement of the weight percentage of dissolved solids in 60 degrees Fahrenheit water, calculated in °Plato or °Balling. Specific gravity is used to calculate the amount of extract in wort or beer.

Spent Grains

The solid residue remaining after the wort has been removed by lautering the mash. Usually high in protein (25 percent), spent grains serve as cattle feed.


A white, tasteless but complex carbohydrate made of strings of glucose molecules linked in a chainlike structure. Starches are nature’s primary means of storing food in plants. They then convert to sugars by enzyme activity. Barley starch is enclosed in the endosperm and constitutes 63 to 65 percent of the weight of two-row barley and about 58 percent of that of six-row barley.

Steam Beer

A beer produced by hybrid fermentation, using bottom-fermenting yeast at top-fermenting yeast temperatures (60 to 70 degrees Fahrenheit). Fermentation takes place in long, shallow, panlike vessels called clarifiers, followed by arm conditioning at 50 to 55 degrees Fahrenheit and kraeusening. This style of beer is indigenous to America and was first produced at the end of the 19th century during the Gold Rush in California, where temperatures were too warm for proper fermentation of bottom yeasts. At one time, as many as 27 breweries made steam beer in San Francisco. It is presently brewed by the Anchor Steam Brewing Co. under the registered trademark of Steam Beer, a highly hopped, amber-colored, foamy beer containing 3.8 percent alcohol by weight (4.7 percent alcohol by volume).


To prepare grain for germination by soaking in water.


Free of living organisms, especially microorganisms – bacteria, molds and yeasts.


A rich, dark brew made from roasted malt, often with the addition of caramelized sugar and a reasonably high proportion of hops. See Beer Styles


A generic name for a class of carbohydrates, including fructose, glucose, maltose and lactose. Without qualification, it invariably refers to sucrose. 


Synonym for sun flavor or lightstruck; skunky. 

Sweet Stout

The English version of stout as opposed to the dry stout of Ireland. It has a slightly lactic flavor and contains less alcohol than dry stout. 

Sweet Wort

The sugary liquid obtained by mashing and sparging malt. 


Additional spargings drawn from the straining vessel after the brew kettle has been filled. This low-extract wort can be used in mashing of another brew and reduce the raw materials required by the amount of extract recovered in the sweetwater. 


Term used to sometimes describe the cooling coils for attemperating a fermentor. This carries over from the days before mechanical refrigeration when blocks of ice called “swimmers” controlled fermentation temperatures.




Any of a group of organic compounds contained in certain grains and other plants. Hop tannins have the ability to help precipitate haze-forming protein materials during the boiling (hot break) and cooling (cold break) of the wort. Tannin is present mainly in the bracts and twigs of the hop cone and imparts an astringent taste to beer. Also called hop tannin as opposed to tannins originating from malted barley. The greater part of the tannin content in wort derives from malt husks, but malt tannins differ chemically from hop tannins. 

  1. The lever that releases the beer from a tapped keg.
  2. To tap, or open, a keg of draught beer.
  3. A taproom, a place where draught beer is served. 

To begin emptying a brewing vessel or to begin straining.

Taste Test

A test carried out in the industry to evaluate a new product or changes in an existing product, usually held by a panel of experts and sometimes consumers. 


A place where alcohol beverages are sold for consumption on the premises.

Tied House

In England, a pub, inn or restaurant under agreement to buy all its beer from a single brewer. Tied houses are usually owned by the brewer.

Top Fermentation

One of the two most basic fermentation methods characterized by the fact that dormant yeast cells rise to the surface during fermentation. Primary fermentation occurs at 59 to 77 degrees Fahrenheit and lasts for about one week. 

Trappist Beer

Any beer brewed in one of the remaining abbeys in Belgium and the Netherlands. Trappist beers are top-fermented, deep-hued (amber or brown) and fairly strong — ranging from 4.7 to 12 percent alcohol by volume (4 to 9.6 percent alcohol by weight). They are fruity and often bittersweet. They are bottleconditioned by priming and reyeasting. The origin of Trappist beers dates back to the Middle Ages, when epidemics were spread by contaminated water. Monasteries located on the traveling route to pilgrimage areas provided travelers with food, shelter and a hygienic beverage free of pathologic microbes. 


A protein and tannin precipitate, which results when wort is boiled.

Tunnel Pasteurization

A method of pasteurization for bottled and canned beer. It consists of a tunnellike apparatus in which the bottles are sprayed with hot water (preheating and pasteurizing) and later with cold water (precooling and cooling). The entire process takes about an hour and the output ranges from 2,000 to 60,000 bottles or cans per hour. 


Cloudiness or lack of clarity, specifically in the filtered beer. Turbidity can be measured both visually and electronically. 

Two-Row Barley

A variety of barley on which only the central spikelet is fertile, forming two rows of grains each. It is the variety most appreciated for brewing because its kernels are better developed and the husk is thinner; however, it generally has a lower amount of enzymes than six-row barley. See Ingredients-Malt




The volume by which a container is underfilled — the space above the beer.


The flavor of glutamic acid (MSG). Beers properly aged on yeast sediment can develop umami-like character


Unitanks combine the features of a brewery fermenter and a bright tank into a single vessel. Unitanks allowing brewers to ferment then carbonate their beer using just a single vessel. Ideal for smaller craft breweries or for testing lines at larger breweries.


Malt of high amylase (enzyme) strength containing large amounts of unconverted protein because the germinating barley had been dried and kilned before the proteinase enzymes could convert protein materials to amino acids.




Winey, winelike, fruity in a fermented sense. 


Volatiles in beer are divided into seven groups: alcohols (higher alcohols or fusel alcohols), esters, carbonyls, organic acids, sulfur compounds, amines and phenols, and are responsible for most of the flavors found in beer.

Volstead Act

Formally “National Prohibition Act”, a U.S. law enacted in 1919 and which took effect in 1920 to provide enforcement for the Eighteenth Amendment which prohibited the manufacture and sale of alcoholic beverages. Named for Andrew Volstead (R-MN), the chairman of the House Judiciary Committee who led the drive for prohibition.


German for “Recirculate”. At the start of lautering and prior to collecting the wort in the brew kettle, a portion of the wort is recirculated from the lauter tun outlet back onto the top of the grain bed in order to clarify the wort and capture all the available sugars.



  1. A type of beer still popular in Berlin. It is white in color, cloudy and foamy, with a very yeasty nose and taste. It is made from wheat, usually not pasteurized. Traditionally, it is served in a large, widebowled, stem glass with a dash of raspberry syrup.
  2. Weiss is German for white. See Beer Styles.
Wheat Beer

Any beer containing a high proportion of malted wheat. Such beers are now produced mainly in Germany and Belgium. All wheat beers are top-fermented and many are bottle-conditioned by the addition of yeast. See Beer styles.

Wild Yeast
  1. Any airborne yeast.
  2. In the fermenting wort, any yeast other than the cultured strain used for fermentation.  See Beer Styles

The bittersweet sugar solution obtained by mashing the malt and boiling in the hops before it is fermented into beer.


X, Y, Z.


Yeast Microscopic, unicellular, vegetal organisms of the fungus family (eumycophyta), distinct from bacteria since they possess a true nucleus. Brewing yeast, or brewer’s yeast, is classified into three categories: bottom-fermenting yeast, top-fermenting yeast or wild yeasts/other species. Brewer’s yeast is sensitive to heat and may die at exposure to temperatures of 125.6 degrees Fahrenheit or above for 10 minutes or more. During the fermentation process, yeast converts the natural malt sugars into equal parts of alcohol and carbon dioxide gas. Yeast was first viewed under a microscope in 1680 by the Dutch scientist Antoine van Leeuwenhoek. See Ingredients.-Yeast

Yield of Extract
  1. Percentage of raw materials recovered as extract in the wort. Yield may be expressed as a percent of the total raw materials used. However, each type of raw material has a different starch content and as a result, a different potential extract contribution.
  2. Another measure of yield, called “recovery rate,” is extract recovery as a percent of the extract theoretically available and which compensates for the different mixes of materials being used, is most meaningful to the brewer.

Small sampling valve used on tanks and lines.


The branch of applied chemistry related to how yeast does the work of fermentation.