Brewers use unique terms for various aspects of the beer making process and that can create some confusion among beginning brewers, who struggle to understand what the different terms mean in plain everyday language. We are hoping the following partial list, in alphabetical order, can help demystify some of these terms. It is by no means meant to be all-inclusive, definitive, or advanced (you won’t find definitions for “apparent attenuation” vs “real attenuation” here, for example). But it should get you started nicely.
ABV: Alcohol % by volume. You can calculate it if you know the Original Gravity and Final Gravity
Adjunct: An unmalted grain added to the mash, or a grain added to the main mash ingredients
All-grain: A beer making process that uses malted grains and adjunct ingredients in a mash to create wort (The alternative to this would be extract brewing)
Attenuation: A measure of how fully yeast convert sugars in wort
Barley: A grain commonly used in beer brewing, versions of which usually make up the largest portion of the grist
Base malt: A malted grain that makes up the majority of the grist in a mash
BIAB: A brewing process called “Brew In A Bag” which minimizes the need for multiple specialty vessels
Caramel malt: Malted barley which has been kiln dried at a special temperature to contribute flavor and color to the finished beer
Carboy: A large glass or plastic container used for fermentation
Conical: A cylindrical fermenting vessel, typically stainless steel, with its bottom shaped into a cone, which aids in yeast and trub collection and removal
Crystal malt: Interchangeable with “caramel malt”
Dough-in: The step of a mash, where the grain is mixed with the strike water
Extract brewing: The wort is created by dissolving commercially produced malt extract in water (as opposed to a full grain/adjunct mash process)
Fermentation: The process of yeast consuming sugars in wort, which creates alcohol, CO2, and flavor compounds, turning the wort into beer.
Final gravity (FG): The specific gravity of the beer after all fermentation activity is completed
Flocculation: A measure of a yeast strain’s propensity to settle out of suspension at the end of fermentation
Gravity: Refers to the wort’s specific gravity, a measure of the dissolved sugar content
Grist: Malted grains and cereals that have been ground in a mill in preparation for mashing
HERMS: Stands for Heat Exchange Recirculating Mash System, one of several methods used to maintain a steady mash temperature
Chiller: A brewing component, often a copper or stainless steel tubing, used to quickly reduce wort temperature at the end of boil from 212°F to yeast pitching temperature (usually around 70 degrees)
HLT: Stands for Hot Liquor Tank. A separate vessel sometimes used to hold hot water for mash-in and sparge water.
Hops: The flowers of the plant Humulus Lupulus, used in beer making to impart bitterness, flavor, and aroma
Hydrometer: A device used to measure specific gravity
IBU: International Bitterness Unit, a measure of the level of bitterness imparted to a beer by hop additions
Kettle: A vessel used in the brewing process and where the boil takes place
Lauter: The process of separating the sweet wort from the grain bed at the end of the mash
Lauter tun: A vessel used to carry out the lautering process
Malt: A grain that has been allowed to sprout and then had its germination process halted by drying. This kick-starts enzymatic activity, later crucial in allowing beer yeast to convert sugars in worts into beer.
Mash: The process of steeping grist with hot water to promote enzymatic activity in the grain to break down complex carbs into simpler sugars needed for beer making.
Mash Tun: A vessel in which the mashing process takes place. (For most homebrew setups mashing, lautering, and sparging all take place in this same vessel)
Original gravity (OG): The specific gravity of the wort right before yeast is introduced to begin fermentation
Partial mash: The wort is generated mostly by dissolving extract in water but an amount of specialty malts are steeped at typical mash temperatures, to provide some additional color and flavor depth
Pitch: Addition of yeast to the cooled wort so it can ferment it
Refractometer: A device used to measure dissolved sugars in wort
RIMS: Stands for Recirculating Infusion Mash System. One of several methods used to maintain a steady mash temperature.
Sparge: The process of adding hot water to the top of the grain bed while lautering.
Strike water: The water used to mix with grains for mashing
Trub: The debris left over in the bottom of the kettle after the wort has been boiled, chilled, and transferred to a fermenter, made up of proteins, hop matter, etc.
Vorlauf: The process of re-circulation of wort at the end of mash, which helps the grain bed settle into a filtering medium, thus clarifying the wort before transferring to the boil process.
Wheat: A widely used grain, both in malted and unmalted forms for many beer styles.
Wort: The sweet water collected after the mashing/sparging/lautering process
Yeast: Living microorganisms which ferment sugars in beer wort. There are many, many strains of beer yeast but most often we speak of ale (“top fermenting”) yeasts and lager (“bottom fermenting”) yeasts. Ale yeasts typically ferment best at relatively warmer temperatures around 65-70°F and lager yeasts like it a bit cooler, 45-58°F.