Home Brewing Glossary: 50+ Terms You Should Know

Speaking the Language of Brewing

Home brewing has its own vocabulary. Understanding these terms will help you follow recipes, troubleshoot problems, and communicate with fellow brewers. This glossary covers the essential terminology from brew day basics to advanced concepts.

Basic Brewing Terms

Wort

Pronounced "wert." The sweet liquid produced by mashing grain or dissolving malt extract in water. Wort becomes beer after yeast ferments it. Think of it as unfermented beer.

Mash

The process of mixing crushed grain with hot water to activate enzymes that convert starch into fermentable sugars. Also refers to the grain-water mixture itself.

Sparge

Rinsing the grain bed with hot water after mashing to extract remaining sugars. Batch sparging (adding water in batches) and fly sparging (continuously trickling water) are the two main methods.

Boil

Heating the wort to a vigorous rolling boil, typically for 60 minutes. The boil sterilizes, extracts hop bitterness, drives off unwanted compounds, and concentrates the wort.

Pitch

Adding yeast to cooled wort to begin fermentation. Proper pitching rate (the right amount of yeast for your batch size and gravity) is critical for clean fermentation.

Fermentation

The process where yeast consumes sugars and produces alcohol, CO2, and flavor compounds. Primary fermentation is the initial vigorous phase. Secondary (or conditioning) is the slower cleanup phase.

Attenuation

The percentage of sugar that yeast converts to alcohol. A beer with 75% apparent attenuation means yeast consumed 75% of the measured sugars. Higher attenuation means a drier, thinner beer.

Measurement Terms

Original Gravity (OG)

The specific gravity of wort before fermentation begins. Indicates sugar content. Measured with a hydrometer or refractometer. Higher OG means more potential alcohol.

Final Gravity (FG)

The specific gravity after fermentation is complete. The difference between OG and FG determines alcohol content. Use our ABV Calculator to convert these readings.

ABV (Alcohol By Volume)

The percentage of alcohol in the finished beer. Calculated from OG and FG readings.

IBU (International Bitterness Units)

A measurement of hop bitterness in beer. Ranges from near zero (wheat beer) to 100+ (double IPA). Calculate yours with our Hop Bitterness Calculator.

SRM (Standard Reference Method)

A measurement of beer color. Ranges from 2 (pale straw) to 40+ (opaque black). Light lagers are 2-4 SRM, amber ales are 10-17 SRM, stouts are 30+ SRM.

Lovibond (L)

A color measurement for malt. Crystal 60L means Crystal malt with a color rating of 60 Lovibond. Higher numbers mean darker malt.

Ingredients and Process Terms

DME / LME

Dry Malt Extract and Liquid Malt Extract. Concentrated wort products used in extract brewing. DME is a powder, LME is a syrup. Both dissolve in water to create wort.

Base Malt

The primary grain in a recipe, providing most of the fermentable sugars. Examples: 2-Row, Pilsner, Maris Otter, Munich.

Specialty Malt

Malts used in smaller quantities for flavor, color, and body. Crystal/Caramel malts, roasted malts, and character malts all fall in this category.

Alpha Acid (AA%)

The percentage of bittering compounds in hops. Higher alpha acid means more bitterness per ounce. Ranges from about 2% (noble hops) to 18%+ (super-alpha varieties).

Dry Hopping

Adding hops directly to the fermenter (no heat) to extract aroma without bitterness. A defining technique in modern IPAs and pale ales.

Krausen

The foamy head that forms on top of fermenting beer during active fermentation. A thick, rocky krausen is a sign of healthy, vigorous fermentation.

Trub

The sediment of proteins, hop material, and dead yeast that settles to the bottom of the fermenter. Leave it behind when transferring beer.

Advanced Terms

Flocculation

The tendency of yeast to clump together and settle out of beer after fermentation. High-flocculation yeasts produce clearer beer. Low-flocculation yeasts stay in suspension longer (useful for hazy styles).

Ester

Fruity flavor compounds produced by yeast during fermentation. Banana, pear, apple, and stone fruit flavors in beer are typically esters. Production increases at higher fermentation temperatures.

Phenol

Spicy, smoky, or sometimes medicinal flavor compounds. Desirable in Belgian and German wheat beers (clove, pepper). Undesirable when caused by contamination or chlorine.

Diacetyl

A buttery or butterscotch off-flavor produced naturally during fermentation. Healthy yeast reabsorbs it during conditioning. A diacetyl rest (raising temperature near end of fermentation) helps.

Cold Crash

Rapidly dropping beer temperature to near freezing (32-38°F) after fermentation to encourage yeast and proteins to settle out, producing clearer beer.