Beer Terminology Glossary

18th Amendment

The 18th Amendment to the United States Constitution established Prohibition. It made it illegal to produce, transport, and sell alcoholic beverages. However, it did not ban the consumption or private possession of alcohol.

21st Amendment

The 21st Amendment repealed Prohibition by overturning the 18th Amendment. It officially ended the nationwide ban on alcohol that had been in effect since January 17, 1920.

AHA (American Homebrewers Association)

Founded in 1978, the American Homebrewers Association (AHA) champions the rights of homebrewers. It publishes Zymurgy magazine, hosts the world’s largest beer competition, and operates as a division of the Brewers Association.

Acetaldehyde

Acetaldehyde is a chemical byproduct of fermentation. It is often perceived as the aroma and flavor of green apples in beer.

Acid Rest

Traditional brewers perform an acid rest early in the mash at around 95°F. This step helps lower the mash’s pH and prepares it for proper fermentation.

Acrospire

The acrospire is the shoot that emerges from a barley grain during germination. Its growth is a key indicator of the malting process.

Adjunct

An adjunct is any unmalted grain or fermentable ingredient used in brewing. Common adjuncts include rice, corn, honey, and syrups. Mass-produced American lagers often use adjuncts to create lighter flavors.

Aeration

Aeration introduces oxygen into the wort at different brewing stages. It promotes healthy yeast fermentation when done before fermentation. After fermentation, however, aeration can cause off-flavors like cardboard or paper aromas due to oxidation.

Alcohol

Specifically ethyl alcohol or ethanol, is the primary intoxicating component of beer. Alcohol content varies widely in beer, from under 3.2% ABV to over 14%, with most craft beers averaging around 5.9% ABV.

Alcohol by Volume (ABV)

ABV measures the alcohol content as a percentage of total liquid volume. It’s calculated by subtracting the final gravity from the original gravity and dividing by 0.0075. For instance: (1.050 – 1.012) ÷ 0.0075 = 5% ABV.

Alcohol by Weight (ABW)

ABW measures the alcohol content based on the weight of alcohol per volume of beer. It is always lower than ABV. To calculate ABW: (1.050 – 1.012) ÷ 0.0095 = 4% ABW.

Alcoholic

The term “alcoholic” refers to two things:

• A warming taste of ethanol and higher alcohols perceived as spicy or vinous in character. Higher ABV beers tend to have a fuller mouthfeel and noticeable alcohol aromas and flavors.

• A person suffering from a disabling disorder marked by compulsive, uncontrolled alcohol consumption.

Ale

Ale is beer fermented with top-fermenting yeast strains. It typically ferments at warmer temperatures than lagers and is often served less chilled. While ale is sometimes mistaken for being stronger in alcohol, the term actually refers to the fermentation method, not the strength.

Ale Yeast

Ale yeast refers to Saccharomyces cerevisiae, a top-fermenting yeast. It thrives between 60°F and 70°F and tends to produce more flavorful compounds compared to lager yeasts.

All-Extract Beer

All-extract beer is brewed entirely with malt extract. It differs from beers brewed with grain or a mix of malt extract and grain, making it a common starting point for beginner homebrewers.

All-Malt Beer

An all-malt beer is brewed solely from mashed barley malt. It excludes adjuncts, added sugars, or any alternative fermentable ingredients, resulting in a purer malt flavor.

Alpha Acid

Alpha acids are one of two primary soft resins found in hops. During the boil, alpha acids transform into iso-alpha acids, providing most of the beer’s bitterness. Over time, oxidized alpha acids can reduce bitterness.

Alpha and Beta Amylase

These are crucial brewing enzymes. Alpha amylase and beta amylase each work best at specific temperatures, influencing the balance between fermentable and non-fermentable sugars in the wort.

Apparent Attenuation

Apparent attenuation measures how much sugar yeast has consumed during fermentation. It’s calculated by subtracting the final gravity from the original gravity and dividing by the original gravity, then multiplying by 100. Most beers achieve apparent attenuation rates between 65% and 80%.

Aromatic Hops

Aromatic hops are added later in the boiling process. Shorter boil times allow more of the hops’ fragrant oils to survive, enhancing beer aroma without contributing much bitterness.

Astringency

Astringency is a drying, puckering mouthfeel in beer. It usually results from tannins, oxidized phenols, or aldehydes, and is sometimes described as a sensation similar to over-steeped tea.

Attenuation

Attenuation refers to the reduction of wort’s specific gravity as yeast consumes sugars during fermentation. This process transforms sugars into alcohol and carbon dioxide, helping define a beer’s body and alcohol content.

Autolysis

Autolysis occurs when excess yeast cells break down and consume each other. This process releases compounds that can cause rubbery, meaty, or vegetal off-flavors in beer.

Barley

Barley is a cereal grain derived from Hordeum vulgare. It serves as the primary grain in beer brewing and distillation. Barley provides essential starches that convert into sugars during mashing, fueling fermentation.

Barrel

In brewing, a barrel can mean two things:

• A standard U.S. measurement equal to 31 gallons.

• A wooden vessel used to age, condition, or ferment beer. Some barrels are brand new, while others previously held wine or spirits, imparting unique flavors to the beer.

Beta Acids

Beta acids are one of two primary soft resins found in hops. Unlike alpha acids, beta acids contribute little bitterness but add preservative qualities. Their impact becomes more noticeable during beer aging.

Bitterness

Bitterness in beer comes from tannins and iso-humulones derived from hops. It balances sweetness and helps define beer styles, ranging from mildly bitter pilsners to intensely hoppy IPAs.

Bitterness Units (BU)

Bitterness Units (BU) are identical to International Bitterness Units (IBU). This measurement reflects the concentration of bitter compounds, helping brewers and drinkers gauge a beer’s perceived bitterness.

Bittering Hops

Bittering hops are added early during the boil. The extended boiling time extracts more bittering compounds, contributing significantly to the final taste of the beer.

BJCP (Beer Judge Certification Program)

Founded in 1985, the Beer Judge Certification Program (BJCP) promotes beer literacy and appreciation. It also certifies beer judges, emphasizing tasting and evaluation skills.

Blending

Blending involves mixing different batches of beer to create a final product. Brewers use blending to balance flavors, adjust alcohol levels, or craft specialty beers like gueuze and barrel-aged blends.

Body

Body refers to the thickness and mouthfeel of a beer. It can range from thin to full-bodied and affects how the beer coats the palate during drinking.

Boiling

Boiling is a vital step in brewing. Wort is heated in the brew kettle, hops are often added, and volatile compounds like dimethyl sulfide are evaporated. Boiling also sterilizes the wort and halts enzymatic activity.

Bomber

A bomber is a 22-ounce glass bottle commonly used to package specialty beers. Bombers are popular for limited releases and higher-end craft brews.

Bottle Conditioning

Bottle conditioning is the process of naturally carbonating beer inside the bottle. Brewers add a small amount of sugar or wort before sealing, which triggers secondary fermentation and creates carbonation.

Bottom Fermentation

Bottom fermentation uses yeast strains that settle at the bottom of the fermentation vessel. This method, common in lagers, operates at cooler temperatures than top fermentation.

Brettanomyces

Brettanomyces is a genus of single-celled yeast that ferments sugars and produces unique sensory flavors. Known casually as “Brett,” it plays an important role in both the beer and wine industries. This yeast can introduce acidity along with distinctive aromas and flavors, often described as leather, barnyard, horse blanket, or earthy funk.

Depending on the style, these characteristics may be desirable or considered flaws. Brettanomyces is a defining element in traditional styles like Lambic and Oud Bruin. It also appears commonly in several American sour ales and many barrel-aged beers, where its funky notes add depth and complexity.

Brewers Association

The Brewers Association is a nonprofit organization dedicated to promoting craft brewers in the United States. It represents more than 4,900 U.S. brewery members and tens of thousands of homebrewers and beer enthusiasts.

Brewpub

A brewpub is a restaurant-brewery that sells at least 25% of its beer on-site. Often, brewpubs serve beer directly from brewery tanks and, where legal, offer packaged beer to-go.

Brew Kettle

The brew kettle is where the wort is boiled during brewing. Hops are often added here, and the boil helps sterilize the wort and develop crucial beer flavors.

Bung

A bung is a stopper, usually made of wood or plastic, that seals the bung hole in a cask or traditional keg. It prevents beer from leaking and protects against contamination.

Bung Hole

The bung hole is the round opening in a cask or keg used for filling the vessel with beer. After filling, brewers seal it with a bung to maintain freshness.

Burton Snatch

Burton snatch describes the sharp sulfur aroma often associated with beers brewed in Burton-on-Trent. The distinctive scent is linked to high sulfate content in the brewing water.

Byproducts

Byproducts are compounds produced during brewing, mashing, and fermentation. Some are desirable, contributing to flavor and aroma, while others can cause off-flavors if not controlled.

Calcium Carbonate (CaCO₃)

Calcium carbonate, also known as chalk, is a mineral sometimes added during brewing. It raises mash pH and increases calcium levels in brewing water, impacting flavor and stability.

Calcium Sulfate (CaSO₄)

Known as gypsum, calcium sulfate is added to brewing water to enhance calcium and sulfate content. It can accentuate hop bitterness and contribute to a drier beer profile.

Carbohydrates

Carbohydrates are organic compounds found in malted barley. They provide essential sugars that yeast consumes during fermentation, producing alcohol and carbon dioxide.

Carbon Dioxide (CO₂)

Carbon dioxide is a natural byproduct of yeast fermentation. It creates the bubbles, head, and lively mouthfeel that make beer so refreshing.

Carbonation

Carbonation introduces carbon dioxide into beer. Brewers carbonate beer by capturing natural fermentation gases, injecting CO₂ under pressure, or priming bottles with sugar for a secondary fermentation.

Carboy

A carboy is a large container used in brewing, typically made of glass or plastic. Homebrewers often use carboys for fermenting or aging beer because they are easy to clean and allow visual monitoring.

Caryophyllene

Caryophyllene is one of the essential oils found in hop cones. It contributes spicy, woody, and sometimes peppery notes to the aroma and flavor of beer.

Cask

A cask is a barrel-shaped container traditionally made of wood but now commonly constructed from stainless steel or aluminum. Casks are used to store, ferment, or condition beer, especially in traditional cask ale brewing.

Cask Conditioning

Cask conditioning involves aging unfiltered, unpasteurized beer in a cask at cool temperatures. During this process, the beer undergoes natural carbonation and flavor development, often resulting in a smoother, more complex brew.

Cellaring

Cellaring refers to the process of storing or aging beer at controlled, cool temperatures. This maturation period allows flavors to mellow and undesirable compounds to diminish, resulting in a smoother final product.

Chill Haze

Chill haze appears when proteins and tannins naturally found in beer form visible particles as the beer cools. While it causes a cloudy look, chill haze usually does not affect taste.

Closed Fermentation

Closed fermentation occurs in sealed vessels, keeping oxygen and wild contaminants out. This method reduces the risk of spoilage and oxidation, resulting in cleaner beer flavors.

Cold Break

Cold break describes the rapid coagulation and settling of proteins and tannins during wort cooling. Achieving a good cold break is crucial for clear beer and improved shelf stability.

Color

Beer color ranges from pale straw to deep black and primarily comes from the grains used in brewing. Caramelized, toasted, or roasted malts create darker hues. While color can hint at flavors, it doesn’t always correlate with alcohol content, body, or bitterness.

Conditioning

Conditioning is the maturation stage after fermentation where beer flavors stabilize and refine. This step reduces unwanted compounds and improves clarity, mouthfeel, and carbonation.

Contract Brewing Company

A contract brewing company outsources beer production to another brewery. The contracting brand focuses on marketing, sales, and distribution, while the hired brewery handles brewing and packaging.

Craft Brewery

The Brewers Association defines a craft brewery as small, independent, and traditional:

• Small: Produces 6 million barrels of beer or less per year.

• Independent: Less than 25% ownership or control by an alcohol industry member that isn’t itself a craft brewer.

• Brewer: Holds a TTB Brewer’s Notice and actively makes beer.

Decoction Mash

Decoction mashing involves removing a portion of the mash, boiling it, and returning it to raise the mash temperature. Brewers often repeat this process multiple times for richer malt flavors.

Degrees Plato

Degrees Plato is a scale used to measure the concentration of dissolved solids (mostly sugars) in wort. It helps brewers predict alcohol content and fermentation performance.

Dextrin

Dextrins are complex, unfermentable carbohydrates created during mashing. They contribute to beer body and mouthfeel without adding sweetness.

Diacetyl

Diacetyl is a fermentation byproduct that gives a buttery, caramel, or butterscotch flavor. While acceptable in some traditional styles, high levels are usually considered a flaw.

Diastatic

The term “diastatic” refers to enzymes created during malting. These enzymes convert starches into fermentable sugars during mashing, making brewing possible.

Dimethyl Sulfide (DMS)

At low levels, DMS adds a sweet corn-like aroma to beer. At higher concentrations, it creates undesirable flavors like cooked corn or celery. Proper boiling reduces DMS levels.

Draught Beer

Draught beer is served from kegs, casks, or tanks rather than bottles or cans. Fresh growler fills are sometimes considered draught beer if consumed soon after filling.

Dry Hopping

Dry hopping involves adding hops late in fermentation or post-fermentation. It boosts hop aroma without significantly increasing bitterness.

Dual Purpose Hops

Dual purpose hops provide both bitterness and aromatic qualities. Brewers use them to simplify recipes or to create balanced, complex beers.

Endosperm

The endosperm is the starchy part of the barley grain. During mashing, enzymes break down the endosperm into fermentable sugars needed for brewing.

Essential Hop Oils

Essential hop oils create the aromas and flavors associated with hops. They are delicate and can easily evaporate if boiled too long, so late or dry hopping preserves them.

Esters

Esters are fruity flavor compounds produced during fermentation. Common ester notes include banana, pear, and apple, especially prominent in ales.

Ethanol

Ethanol, or ethyl alcohol, is the main alcohol component in beer. It’s produced when yeast ferments sugars and is responsible for beer’s intoxicating effects.

Export

Export refers to beer brewed specifically for international shipment. Some beer styles, like Export Stouts and German Export Lagers, historically developed for overseas markets.

Farnesene

Farnesene is an essential hop oil that adds delicate floral and green apple notes. It appears in small amounts in many noble hop varieties.

Fermentable Sugars

Fermentable sugars are simple carbohydrates that yeast converts into alcohol and carbon dioxide during fermentation. Common types include glucose, fructose, maltose, and maltotriose.

Fermentation

Fermentation transforms sugars into alcohol and carbon dioxide through yeast activity. Ales use top fermentation at warmer temperatures, while lagers use bottom fermentation at cooler temperatures.

Fermentation Lock

A fermentation lock is a one-way valve placed on fermenters. It allows carbon dioxide to escape while preventing outside air, bacteria, and wild yeast from entering.

Filtration

Filtration removes solid particles such as yeast, proteins, and hop debris from beer. Brewers filter to improve clarity, stability, and shelf life.

Final Gravity

Final gravity measures the density of beer after fermentation. It indicates how much sugar remains and helps calculate alcohol content.

Fining

Fining is the addition of substances like isinglass, gelatin, or silica to beer. These agents help settle suspended particles, improving beer clarity.

Flocculation

Flocculation describes how yeast cells and other particles clump together and settle out of solution. It affects both fermentation and the final beer’s clarity.

Forced Carbonation

Forced carbonation involves injecting carbon dioxide directly into beer under pressure. This method is commonly used in commercial brewing to quickly carbonate beer without relying on natural fermentation.

Fresh Hopping

Fresh hopping, also known as wet hopping, uses newly harvested, undried hop cones. Brewers add them during various stages of brewing to impart fresh, green, and floral hop character not found in dried hops.

Fusel Alcohol

Fusel alcohols are higher molecular weight alcohols produced at elevated fermentation temperatures. They can create solvent-like flavors such as paint thinner or nail polish remover and are often associated with harsh mouthfeel or stronger hangovers.

Germination

Germination is the sprouting stage of malting when barley grains begin to grow rootlets and acrospires. This activates enzymes essential for converting starches into sugars during mashing.

Grainy

Grainy describes a beer flavor or aroma reminiscent of raw grains or breakfast cereal. It can stem from under-modified malts, certain adjuncts, or incomplete mashing.

Grist

Grist is the mixture of milled malt and grains used in brewing. It is prepared before mashing and must be ground to the right consistency to extract fermentable sugars efficiently.

Growler

A growler is a glass or stainless steel container, usually 64 ounces or 2 liters, used for transporting draught beer. Brewpubs often fill growlers for take-home sales. In many states, customers can refill them multiple times.

Gruit

Gruit is an old-fashioned herbal mixture used to flavor beer before hops became dominant. Common gruit ingredients included yarrow, mugwort, rosemary, and juniper. Some brewers today revive this style for historical or unique flavor profiles.

Hand Pump

A hand pump is a manual device for serving cask-conditioned beer. It pulls beer from the cask without using pressurized gas, maintaining traditional serving conditions and preserving natural carbonation.

Head Retention

Head retention measures how long a beer maintains a foamy head after pouring. Good head retention enhances aroma and appearance. Proteins and carbonation levels significantly influence foam stability.

Heat Exchangers

Heat exchangers rapidly cool wort before fermentation by transferring heat to cold water or glycol. This step is crucial to prevent contamination and protect yeast during pitching.

Homebrewing

Homebrewing is the process of making beer at home. Legalized in the U.S. in 1979, it allows individuals to produce up to 100 gallons per adult, per household annually. The practice is popular among hobbyists and experimental brewers.

Hops

Hops (Humulus lupulus) are the flowers of a climbing bine used to flavor and preserve beer. They contribute bitterness, aroma, and flavor. Female cones contain essential oils and resins that are added during various brewing stages. Classic varieties include Cascade, Saaz, Fuggles, and Tettnang.

Hopping

Hopping refers to the process of adding hops to the wort or beer. Early additions contribute bitterness, mid additions bring flavor, and late or dry hopping enhances aroma.

Hot Break

Hot break occurs during wort boiling, where proteins and tannins coagulate and rise to the surface. Removing these solids improves clarity and flavor stability.

Humulene

Humulene is a key hop oil contributing earthy, woody, and spicy aromas. It’s most abundant in traditional European hop varieties and degrades quickly when boiled.

Husk

The husk is the outer shell of a grain, especially barley. It plays a vital role during lautering by acting as a natural filter bed for the sweet wort.

Hydrometer

A hydrometer is a tool used to measure the specific gravity of liquids. Brewers use it to determine sugar concentration before and after fermentation, helping calculate alcohol content.

Immersion Chiller

An immersion chiller is a coil-shaped heat exchanger, usually made from copper or stainless steel. It’s submerged into hot wort to rapidly reduce temperature before fermentation.

Infusion Mash

An infusion mash raises mash temperature by adding hot water. It’s a common and simple method for maintaining specific temperature rests during the mashing process.

Inoculate

To inoculate is to introduce a microorganism, such as yeast or bacteria, into wort or beer. This starts fermentation or encourages desired flavor development.

International Bitterness Units (IBU)

IBU is a standardized measure of bitterness in beer, based on the amount of isomerized alpha acids. Pale lagers typically have 5–15 IBUs, while IPAs may exceed 70.

Irish Moss

Irish moss is a type of seaweed added near the end of the boil. It helps proteins clump and settle out, improving beer clarity by aiding the hot break.

Isinglass

Isinglass is a gelatin-like fining agent made from fish swim bladders. It’s added to beer during conditioning to clarify by binding with suspended particles and encouraging them to settle.

Keg

A keg is a cylindrical vessel, usually made of stainless steel, used to store and dispense beer under pressure. U.S. kegs typically hold 15.5 gallons (half-barrel), though various sizes like quarter-barrel and sixth-barrel are also common.

Kilning

Kilning is the process of drying malted barley in a kiln after germination. This step halts sprouting and develops key flavors, aromas, and colors essential for beer styles.

Kraeusen (noun and verb)

As a noun, kraeusen refers to the foamy head formed during active fermentation. As a verb, kraeusening means adding actively fermenting wort to finished beer to naturally carbonate it.

Lace

Lace is the pattern of foam that clings to the sides of a beer glass as the beer is consumed. Well-formed lace is often a sign of good head retention and protein content.

Lactobacillus

Lactobacillus is a bacteria that can sour beer by converting sugars into lactic acid. While considered a spoilage organism in some beers, it is desirable in sour styles like Berliner Weisse and Gose.

Lager

Lager refers to any beer fermented with bottom-fermenting yeast at cool temperatures. Lagers are typically crisp and clean, with fermentation temperatures ranging from 45°F to 55°F.

Lager Yeast

Lager yeast, Saccharomyces pastorianus, is a bottom-fermenting strain used at lower temperatures. It often produces fewer fruity esters and can yield subtle sulfuric notes.

Lagering

Lagering is the cold maturation phase for lagers. This process can last weeks to months, helping the beer clarify, smooth out, and develop a refined flavor profile.

Large Brewery

According to the Brewers Association, a large brewery produces more than 6 million barrels of beer annually. These breweries often have national or global distribution.

Lauter Tun

The lauter tun is a vessel with a false bottom used to separate sweet wort from spent grains. It allows the liquid to drain while grains remain behind.

Lautering

Lautering is the process of draining sweet wort from the mash. Brewers may also rinse the grain bed with hot water (sparging) to extract additional sugars.

Lightstruck (Skunked)

Lightstruck beer develops off-flavors and aromas resembling skunk spray when exposed to ultraviolet light. Green and clear bottles offer less protection than brown ones.

Liquor

In brewing, liquor refers to the water used for mashing and brewing, especially when treated to control mineral content. Water chemistry heavily influences beer flavor and mouthfeel.

Lovibond

Lovibond is a scale that measures the color of malt and beer. Lighter beers like pilsners score low on the scale, while stouts and porters rank much higher.

Magnum Bottle

A magnum bottle holds 1.5 liters of beer, equal to two standard 750-milliliter bottles. Magnum packaging is often used for special releases, aging projects, and celebration beers.

Malt

Malt is barley (or occasionally other grains) that has been soaked, germinated, and kiln-dried. This process develops the enzymes necessary to convert starches into fermentable sugars during brewing.

Malt Extract

Malt extract is a concentrated form of wort, available in syrup or powder form. It’s often used by homebrewers and commercial brewers to simplify brewing or boost original gravity.

Maltose

Maltose is the most abundant fermentable sugar found in beer wort. Yeast readily ferments maltose into alcohol and carbon dioxide during brewing.

Mash

The mash is the mixture of crushed malted grains and hot water. During mashing, enzymes break down starches into fermentable sugars, creating the sweet wort.

Mash Tun

A mash tun is the brewing vessel where grains and water combine to form the mash. It provides the controlled environment necessary for enzymatic activity and sugar extraction.

Mashing

Mashing is the process of converting grain starches into fermentable sugars. Brewers carefully control time and temperature to optimize enzyme activity and flavor development.

Mashing Out

Mashing out involves raising the mash temperature to about 170°F. This step halts enzymatic activity and makes it easier to separate the wort from the grain bed.

MBAA (Master Brewers Association of the Americas)

Founded in 1887, the MBAA promotes education and technical advancement in brewing and malting. It offers resources and networking opportunities for industry professionals.

Microbrewery

A microbrewery, by Brewers Association definition, produces fewer than 15,000 barrels of beer annually. Microbreweries typically sell the majority of their beer off-site through distributors or direct sales.

Milling

Milling is the grinding of malt into grist before mashing. The goal is to expose the starchy endosperm while preserving the husk to act as a natural filter during lautering.

Modification

Modification describes the physical and chemical changes that occur during malting. Proper modification ensures that barley starches and proteins are easily converted during mashing.

Modified Malts

Modified malts have undergone extended germination, breaking down internal structures to optimize enzyme activity. They simplify the mashing process and create more consistent brewing results.

Mouthfeel

Mouthfeel is the sensation of beer in the mouth, influenced by carbonation, viscosity, alcohol content, and astringency. It can range from thin and crisp to rich and creamy.

Musty

Musty describes a stale, moldy, or mildewy aroma or flavor in beer. It often results from cork taint, bacterial contamination, or improper storage conditions.

Myrcene

Myrcene is a prominent essential oil in hop cones. It contributes fresh, herbal, and citrus aromas to beer, and is most abundant in American hop varieties like Cascade and Amarillo.

Natural Carbonation

Natural carbonation occurs when fermentable sugars are added to beer before packaging. Yeast consumes the sugars, releasing carbon dioxide that dissolves into the beer, creating bubbles naturally.

Ninkasi

Ninkasi is the ancient Sumerian goddess of beer and brewing. She symbolizes the deep historical roots of brewing culture, with references dating back over 4,000 years.

Nitrogen

Nitrogen is used to carbonate certain beers, such as stouts. It produces smaller bubbles than carbon dioxide, creating a thick, creamy mouthfeel and a dense, smooth head.

Noble Hops

Noble hops are traditional European hop varieties known for their delicate aroma and flavor. The classic noble varieties include Hallertau, Saaz, Spalt, and Tettnang, prized for floral, spicy, and herbal qualities.

Oasthouse

An oasthouse is a farm facility where freshly harvested hops are dried and processed. Proper drying preserves hop aroma and flavor for brewing use.

Original Gravity (OG)

Original gravity measures the density of wort before fermentation. It indicates the potential alcohol content and sweetness of the final beer.

Oxidation

Oxidation is a chemical reaction that occurs when beer is exposed to oxygen. It can lead to stale, cardboard-like flavors and significantly reduce beer freshness.

Oxidized

Oxidized beer exhibits undesirable flavors such as wet paper, sherry, or rotten pineapple. Oxidation often occurs from improper packaging, storage, or exposure to light and air.

Package

Package refers to the container used to market and distribute beer, such as bottles, cans, or kegs. Packaged beer is distinct from draught beer served directly from kegs or casks.

Palate

The palate is the roof of the mouth and is key to how we perceive flavor, texture, and mouthfeel in beer. It detects sweetness, bitterness, sourness, and more.

Pediococcus

Pediococcus is a type of bacteria that can spoil beer by producing lactic acid and diacetyl. However, it is intentionally used in certain sour beer styles like Lambics for its tart contributions.

pH

pH measures the acidity or alkalinity of a liquid on a scale from 0 to 14. In brewing, a proper mash pH (around 5.2–5.6) ensures good enzyme activity and flavor balance.

Phenols

Phenols are a class of chemical compounds found in beer, detectable by aroma and flavor. Desirable phenolic notes include clove and spice, while undesirable ones can smell medicinal or plastic-like. They may originate from yeast strains, water chemistry, or infections.

Pitching

Pitching is the act of adding yeast to cooled wort to initiate fermentation. Proper pitching rates are critical for healthy fermentation and final beer quality.

Primary Fermentation

Primary fermentation is the initial and most active stage of fermentation. Yeast rapidly converts sugars into alcohol and carbon dioxide during this time, typically lasting from a few days to two weeks.

Priming

Priming involves adding a small amount of fermentable sugar to beer before packaging. This extra sugar reactivates yeast, naturally carbonating the beer inside bottles or kegs.

Prohibition

Prohibition in the United States, enacted by the 18th Amendment in 1920, banned the production, sale, and transportation of alcoholic beverages. It was repealed in 1933 by the 21st Amendment.

Punt

A punt is the dimpled indentation found at the bottom of many beer and wine bottles. It strengthens the bottle structure and can aid in pouring without disturbing sediment.

Quaff

To quaff means to drink deeply and heartily, often used to describe the enjoyment of beer or other beverages.

Racking

Racking is the process of transferring beer from one vessel to another, usually to separate it from sediment or to prepare it for bottling or kegging.

Real Ale

Real ale undergoes secondary fermentation in its final container and is served without added carbon dioxide pressure. It’s a hallmark of traditional British brewing and championed by CAMRA.

Regional Craft Brewery

A regional craft brewery produces between 15,000 and 6,000,000 barrels of beer annually. It maintains craft brewery independence and brewing traditions while distributing on a larger scale.

Reinheitsgebot

The Reinheitsgebot is the German Beer Purity Law of 1516. It originally allowed beer to be brewed only with water, barley, and hops (yeast was unknown at the time).

Residual Alkalinity

Residual alkalinity measures the ability of brewing water to resist pH changes. It directly affects mash pH and thus influences flavor and fermentation quality.

Residual Sugar

Residual sugar is the amount of sugar left unfermented in beer after fermentation finishes. It can add sweetness and body to the final product.

Resin

Resins are sticky organic compounds found in hop flowers. They contribute bitterness and aroma to beer, particularly alpha and beta acids responsible for bittering and preservation.

Saccharification

Saccharification is the process where enzymes in the mash convert complex starches into fermentable sugars. This crucial step ensures that yeast will have enough food to produce alcohol during fermentation.

Saccharomyces

Saccharomyces is a genus of yeast used in brewing and baking. The two main brewing species are Saccharomyces cerevisiae for ales and Saccharomyces pastorianus for lagers.

Secondary Fermentation

Secondary fermentation refers to the slower phase after primary fermentation. During this stage, the beer clarifies, matures, and can develop additional flavors, often taking weeks or months.

Sediment

Sediment consists of solid particles that settle at the bottom of fermenters, conditioning vessels, or bottles. It is typically composed of spent yeast, proteins, and hop matter.

Session Beer

Session beers are lower in alcohol, usually between 3% and 5% ABV. They allow drinkers to enjoy several servings in one sitting without becoming overly intoxicated.

Solvent-like

Solvent-like aromas or flavors resemble nail polish remover or paint thinner. These undesirable notes are usually the result of high fermentation temperatures or stressed yeast.

Sorghum

Sorghum is a gluten-free cereal grain used as a malt substitute in brewing. It’s popular in brewing for those who are gluten intolerant or producing specialty beers.

Sour

Sour is a flavor characterized by acidity and tartness. In brewing, it’s often created intentionally by bacteria like Lactobacillus or Pediococcus to produce sour styles like Berliner Weisse or Lambic.

Sparging

Sparging involves rinsing the spent grains in the lauter tun with hot water. This step extracts remaining sugars, maximizing the efficiency of the mash.

Specific Gravity

Specific gravity measures the density of a liquid compared to water. Brewers use it before and after fermentation to calculate alcohol content and monitor fermentation progress.

Standard Reference Method (SRM)

The Standard Reference Method (SRM) is the American system for measuring beer color. The higher the SRM number, the darker the beer, ranging from pale lagers to dark stouts.

Steeping

Steeping involves soaking grains or other ingredients in hot water to extract flavors, sugars, or colors. It’s often used in extract brewing to add complexity without full mashing.

Step Infusion

Step infusion is a mashing method where brewers raise the mash temperature by adding boiling water. Each temperature “step” activates different enzymes for optimal sugar extraction.

Sulfur

Sulfur aromas in beer can resemble rotten eggs or burnt matches. While minor sulfur notes are acceptable in some lagers, strong sulfur odors typically indicate fermentation issues or lightstruck beer.

Tannins

Tannins are a group of organic compounds found in malt husks and hops. In excessive amounts, they can cause astringency and puckering mouthfeel, similar to strong black tea.

Temperature Rests

Temperature rests during mashing allow brewers to target specific enzymatic activity. By holding the mash at various temperatures, brewers influence the beer’s body, fermentability, and flavor profile.

Top Fermentation

Top fermentation is a method where yeast rises to the top of the fermenting beer. This process, common with ale yeasts, happens at warmer temperatures between 60°F and 75°F.

Trigeminal Nerves

Trigeminal nerves in the face sense sensations like temperature, carbonation, and astringency. In beer, these nerves contribute to the perception of coolness, heat, texture, and body.

Trub

Trub consists of coagulated proteins, hop debris, and tannins that settle out during wort boiling and cooling. Removing trub helps improve beer clarity and flavor stability.

Turbidity

Turbidity refers to the cloudiness or haziness in beer caused by suspended particles. While some styles embrace turbidity, others strive for brilliant clarity.

Volatile Compounds

Volatile compounds are aromatic substances that easily evaporate at room temperature. In beer, these compounds significantly affect aroma and flavor, including esters, alcohols, and phenols.

Volstead Act

The Volstead Act was the legislation that enforced Prohibition in the United States starting in 1920. It defined alcoholic beverages and outlined penalties, staying in effect until the 21st Amendment repealed it in 1933.

Volumes of CO₂

Volumes of CO₂ measure the amount of dissolved carbon dioxide in beer. Different styles have ideal carbonation levels, ranging from around 1.5 volumes for cask ales to over 4 volumes for some Belgian ales.

Vorlauf

Vorlauf is the process of recirculating wort during lautering. The wort drawn from the bottom of the lauter tun is gently poured back over the grain bed to clarify it before collecting into the kettle.

Water

Water makes up about 90% to 95% of beer. Its mineral content—including calcium, magnesium, and sulfate—greatly influences flavor, fermentation behavior, and final beer character. Famous brewing cities owe much of their reputation to their natural water profiles.

Wet Hopping

Wet hopping involves using freshly picked, undried hops during brewing. Using wet hops will impart unique grassy, vibrant, and floral aromas that differ significantly from dried hop flavors.

Whirlpool

Whirlpooling involves stirring hot wort in a circular motion to collect hop matter and proteins into a tight cone at the center of the kettle. Some breweries also use a separate whirlpool vessel to separate solids more effectively.

Wort

Wort is the sweet, unfermented liquid extracted from the mash. It becomes beer after boiling with hops and fermenting with yeast.

Yeast

Yeast are microscopic fungi responsible for fermenting sugars into alcohol and carbon dioxide. Different yeast strains contribute unique flavors, aromas, and fermentation characteristics to beer.

Yeast Cake

Yeast cake refers to the dense layer of yeast and sediment that settles at the bottom of a fermenter. Some brewers reuse yeast cake for future fermentations after careful harvesting.

Yeast Pitching

Yeast pitching is the act of adding yeast to cooled wort to begin fermentation. Correct pitching rates and healthy yeast are vital for consistent, high-quality beer.

Zymurgy

Zymurgy is the branch of chemistry that deals with fermentation processes, especially in brewing and winemaking. It’s also the name of the American Homebrewers Association’s bi-monthly magazine, focusing on all things homebrewing and craft beer.

If there is a term missing that you would like to see added to our beer terminology glossary, please contact us!