Beers are generally considered to fall into two categories, lagers and ale. The category a beer falls into depends on where fermentation occurs. Ales are made from top-fermenting yeasts which ferment at higher temperatures and produce more esters which create flavors in the beer. Lagers are made from bottom-fermenting yeasts which ferment at lower temperatures. The lower temperatures inhibit ester production, giving the beer a crisp taste. Lagers are the most widely consumed beers in the world. Additionally there are hybrid beers and lambic beers which don't fit into these general categories.
Acetaldehyde - Green apple aroma, a byproduct of fermentation.
Additive- Enzymes, preservatives and antioxidants which are added to simplify the brewing process or prolong shelf life.
Adjunct - Fermentable material used as a substitute for traditional grains, to make beer lighter-bodied or cheaper.
Aerobic - An organism, such as top fermenting ale yeast, that needs oxygen to metabolize.
Alcohol - Ethyl alcohol or ethanol. An intoxicating by-product of fermentation, which is caused by yeast acting on sugars in the malt. Alcohol content is expressed as a percentage of volume or weight.
Alcohol by weight - Amount of alcohol in beer measured in terms of the percentage weight of alcohol per volume of beer, i.e., 3.2% alcohol by weights equals 3.2 grams of alcohol per 100 centiliters of beer. (It is approximately 20% less than alcohol by volume.)
Alcohol by volume - Amount of alcohol in beer in terms of percentage volume of alcohol per volume of beer.
Alcoholic - Warming taste of ethanol and higher alcohol's.
Ale - Beers distinguished by use of top fermenting yeast strains, Saccharomyces cerevisiae. The top fermenting yeast perform at warmer temperatures than do yeast's used to brew lager beer, and their byproducts are more evident in taste and aroma. Fruitiness and esters are often part of an ale's character.
All-malt - Refers to a beer made exclusively with barley malt and without adjuncts.
Amber - Any top or bottom fermented beer having an amber color, between pale and dark.
Anaerobic - An organism, such as a bottom-fermenting lager yeast, that is able to metabolize without oxygen present.
Aroma Hops - Varieties of hop chosen to impart bouquet. (See Hops)
Astringent - A drying, puckering taste; tannic; can be derived from boiling the grains, long mashes, over sparging or sparging with hard water.
Attenuation - Extent to which yeast consumes fermentable sugars (converting them into alcohol and carbon dioxide).
Bacterial - A general term covering off-flavors such as moldy, musty, woody, lactic acid, vinegar, or microbiological spoilage.
Balling Degrees - Scale indicating density of sugars in wort.
Barley - A cereal grain that is malted for use in the grist that is used in mash to brew beer.
Barrel - A unit of measurement used by brewers in some countries. In Britain, a barrel holds 36 imperial gallons (1 imperial gallon = 4.5 liters), or 1.63 hectoliters. In the United States, a barrel holds 31.5 US gallons (1 US gallon = 3.8 liters), or 1.17 hectoliters.
Beer - Name given alcohol-containing beverages produced by fermenting grain, specifically malt, and flavored with hops.
Bitter - Bitterness of hops or malt husks; sensation on back of tongue.
Bitterness - The perception of a bitter flavor, in beer from iso-alpha-acid in solution (derived from hops). It is measured in International Bitterness Units (IBU).
Black malt - Partially malted barley roasted at high temperatures. Black malt gives a dark color and roasted flavor to beer.
Body - Thickness and mouth-filling property of a beer described as "full or thin bodied".
Bottle-conditioning - Secondary fermentation and maturation in the bottle, creating complex aromas and flavors.
Bottom-fermenting yeast - One of the two types of yeast used in brewing. Bottom-fermenting yeast works well at low temperatures and ferments more sugars leaving a crisp, clean taste and then settles to the bottom of the tank. Also referred to as "lager yeast"
Brew Kettle - The vessel in which wort from the mash is boiled with hops. Also called a copper.
Brewpub - Pub that makes its own beer and sells at least 50% of it on premises. Also known in Britain as a home-brew house and in Germany as a house brewery.
Bung The stopper in the hole in a keg or cask through which the keg or cask is filled and emptied. The hole may also be referred to as a bung or bunghole. Real beer must use a wooden bung.
Carbonation - Sparkle caused by carbon dioxide, created during fermentation or injected later.
Caramel - A cooked sugar that is used to add color and alcohol content to beer. It is often used in place of more expensive malted barley.
Caramel malt - A sweet, coppery-colored malt. Caramel or crystal malt imparts both color and flavor to beer. Caramel malt has a high concentration of unfermentable sugars that sweeten the beer and, contribute to head retention.
Cask - A closed, barrel-shaped container for beer. They come in various sizes and are now usually made of metal. The bung in a cask of "Real" beer or ale must be made of wood to allow the pressure to be relived, as the fermentation of the beer, in the cask, continues.
Cask-conditioning - Secondary fermentation and maturation in the cask at the point of sale. Creates light carbonation.
Chill haze - Cloudiness caused by precipitation of protein-tannin compound at low temperatures, does not affect flavor.
Chill proof - Beer treated to allow it to withstand cold temperatures without clouding.
Clovelike - Spicy character reminiscent of cloves; characteristic of some wheat beers, or if excessive, may derive from wild yeast.
Conditioning - Period of maturation intended to impart "condition" (natural carbonation). Warm conditioning further develops the complex of flavors. Cold conditioning imparts a clean, round taste.
Conditioning Tank - A vessel in which beer is placed after primary fermentation where the beer matures, clarifies and, is naturally carbonated through secondary fermentation. Also called bright beer tank, serving tank and, secondary tank.
Contract Beer - Beer made by one brewery and then marketed by a company calling itself a brewery. The latter uses the brewing facilities of the former.
Decoction - Exhaustive system of mashing in which portions of the wort are removed, heated, then returned to the original vessel.
Dextrin - The unfermentable carbohydrate produced by the enzymes in barley. It gives the beer flavor, body, and mouthfeel. Lower temperatures produce more dextrin and less sugar. While higher temperatures produce more sugars and less dextrin.
Diacetyl - A volatile compound in beer that contributes to a butterscotch flavor, measured in parts per million.
DMS - Taste and aroma of sweet corn; results from malt, as a result of the short or weak boil of the wort, slow wort chilling, or bacterial infection. -- Dimethyl sulfide, a sulfur compound.
Dosage - The addition of yeast and/or sugar to the cask or bottle to aid secondary fermentation.
Draft (Draught) - The process of dispensing beer from a bright tank, cask or, keg, by hand pump, pressure from an air pump or, injected carbon dioxide inserted into the beer container prior to sealing.
Dry-hopping - The addition of dry hops to fermenting or aging beer to increase its hop character or aroma.
EBC - European Brewing Convention. An EBC scale is used to indicate colors in malts and beers.
Enzymes - Catalysts that are found naturally in the grain. When heated in mash, they convert the starches of the malted barley into maltose, a sugar used in solution and fermented to make beer.
Ester - Volatile flavor compound naturally created in fermentation. Often fruity, flowery or spicy.
Estery - Aroma or flavor reminiscent of flowers or fruits.
Fermentation - Conversion of sugars into ethyl alcohol and carbon dioxide by yeast.
Final specific gravity - Specific gravity of a beer when fermentation is complete.
Fining - An aid to clarification: a substance that attracts particles that would otherwise remain suspended in the brew.
Filter - The removal of designated impurities by passing the wort through a medium. Yeast in suspension is often targeted for removal.
Fruity/Estery - Flavor and aroma of bananas, strawberries, apples, or other fruit; from high temperature fermentation and certain yeast strains.
Grainy - Tastes like cereal or raw grain.
Grist - Brewers' term for milled grains, or the combination of milled grains to be used in a particular brew. Derives from the verb to grind. Also sometimes applied to hops.
Hand Pump - A device for dispensing draft beer using a pump operated by hand. The use of a hand pump allows the cask-conditioned beer to be served without the use of pressurized carbon dioxide.
Hang - Lingering bitterness or harshness.
Hard Cider - A fermented beverage made from apples.
Heat Exchanger - A mechanical device used to rapidly reduce the temperature of the wort.
Hefe - A German word meaning "yeast". Used mostly in conjunction with wheat (weiss) beers to denote that the beer is bottled or kegged with the yeast in suspension (hefe-weiss). These beers are cloudy, frothy and, very refreshing.
Hogshead - Cask holding 54 imperial gallons ( 243 liters ).
Hop back - Sieve-like vessel used to strain out the petals of the hop flowers. Known as a hop jack in the United States.
Hops - Herb added to boiling wort or fermenting beer to impart a bitter aroma and flavor.
Hoppy - Aroma of hops, does not include hop bitterness.
Infusion - Simplest form of mash, in which grains are soaked in water. May be at a single temperature, or with upward or (occasionally) downward changes.
IBU - International Bitterness units. A system of indicating the hop bitterness in finished beer.
Keg - One-half barrel, or 15.5 U. S. gallons. A half keg or, 7.75 U. S. gallons, is referred to as a pony-keg.
Kräusening - The addition of a small proportion of partly fermented wort to a brew during lagering. Stimulates secondary fermentation and imparts a crisp, spritzy character.
Lager - Beers produced with bottom fermenting yeast strains, Saccharomyces uvarum (or carlsbergensis) at colder fermentation temperatures than ales. This cooler environment inhibits the natural production of esters and other byproducts, creating a crisper tasting product.
Lagering - From the German word for storage. Refers to maturation for several weeks or months at cold temperatures (close to 0°C /32°F) to settle residual yeast, impart carbonation and make for clean round flavors.
Lauter - To run the wort from the mash tun. From the German word to clarify. A lauter tun is a separate vessel to do this job. It uses a system of sharp rakes to achieve a very intensive extraction of malt sugars.
Length - The amount of wort brewed each time the brew house is in operation.
Light-Struck - Skunklike smell; from exposure to light.
Liquor - The brewer's word for water used in the brewing process, as included in the mash or, used to sparge the grains after mashing.
Malt (ing) - The process by which barley is steeped in water, germinated ,then kilned to convert insoluble starch to soluble substances and sugar. The foundation ingredient of beer.
Malt Extract - The condensed wort from a mash, consisting of maltose, dextrins and, other dissolved solids. Either as a syrup or powdered sugar, it is used by brewers, in solutions of water and extract, to reconstitute wort for fermentation.
Malt Liquor - A legal term used in the U.S. to designate a fermented beverage of relatively high alcohol content (7%-8% by volume).
Mash - (Verb) To release malt sugars by soaking the grains in water. (Noun) The resultant mixture.
Mash Tun - A tank where grist is soaked in water and heated in order to convert the starch to sugar and extract the sugars and other solubles from the grist.
Maltose - A water soluble, fermentable sugar contained in malt.
Mead - Meads are produced by the fermentation of honey, water, yeast and optional ingredients such as fruit, herbs, and/or spices. According to final gravity, they are categorized as: dry (0.996 to 1009); medium (1010 to 1019); or sweet (1020 or higher). Wine, champagne, sherry, mead, ale or lager yeasts may be used.
Metallic - Tastes tinny, bloodlike or coinlike; may come from bottle caps.
Microbrewery - Small brewery generally producing less than 15,000 barrels per year.
Mouthfeel - A sensation derived from the consistency or viscosity of a beer, described, for example as thin or full.
Musty - Moldy, mildewy character; can be the result of cork or bacterial infection.
Original gravity - A measurement of the density of fermentable sugars in a mixture of malt and water with which a brewer begins a given batch.
Oxidized - Stale flavor of wet cardboard, paper, rotten pineapple, or sherry, as a result of oxygen as the beer ages or is exposed to high temperatures.
Pasteurization - Heating of beer to 60-79(°C/140-174°F to stabilize it microbiologically. Flash-pasteurization is applied very briefly, for 15-60 seconds by heating the beer as it passes through the pipe. Alternately, the bottled beer can be passed on a conveyor belt through a heated tunnel. This more gradual process takes at least 20 minutes and sometimes much longer.
Phenolic - Flavor and aroma of medicine, plastic, Band-Aids, smoke, or cloves; caused by wild yeast or bacteria, or sanitizer residue.
Pitch - To add yeast to wort.
Plato, degrees - Expresses the specific gravity as the weight of extract in a 100 gram solution at 64°F (17.5°C). Refinement of the Balling scale.
Priming - The addition of sugar at the maturation stage to promote a secondary fermentation.
Pub - An establishment that serves beer and other alcoholic beverages for consumption on premise. The term originated in England and is the shortened form of "public house".
Regional specialty brewery - A brewery that produces more than 15,000 barrels of beer annually, with its largest selling product a specialty beer.
Reinheitsgebot - "Purity Law" originating in Bavaria in 1516 and now applied to all German brewers making beer for consumption in their own country. It requires that only malted grains, hops, yeast and water may be used in the brewing.
Secondary fermentation - Stage of fermentation occurring in a closed container from several weeks to several months.
Shelf life - Describes the number of days a beer will retain it's peak drinkability. The shelf life for commercially produced beers is usually a maximum of four months.
Specific gravity - A measure of the density of a liquid or solid compared to that of water ((1.000 at 39°F (4°C)).
Sparge - To spray grist with hot water in order to remove soluble sugars (maltose). This takes place at the end of the mash.
Squares - Brewers' term for a square fermenting vessel.
Sulfurlike - Reminiscent of rotten eggs or burnt matches; a by-product of some yeast's.
Tart - Taste sensation cause by acidic flavors.
Top-fermenting yeast- One of the two types of yeast used in brewing. Top-fermenting yeast works better at warmer temperatures and are able to tolerate higher alcohol concentrations than bottom-fermenting yeast. It is unable to ferment some sugars, and results in a fruitier, sweeter beer. Also known as "ale yeast".
Tun - Any large vessels used in brewing. In America, "tub" is often preferred.
Vinous - Reminiscent of wine.
Winy - Sherrylike flavor; can be caused by warm fermentation or oxidation in very old beer.
Wort - The solution of grain sugars strained from the mash tun. At this stage, regarded as "sweet wort", later as brewed wort, fermenting wort and finally beer.
Yeast - A micro-organism of the fungus family. Genus Saccharomyces.
Yeasty - Yeastlike flavor; a result of yeast in suspension or beer sitting too long on sediment.