Glossary of Beer Brewing Terms

This glossary of beer brewing terms has many of the terms most commonly encountered in craft beer brewing. Expand your vocabulary and use the same beer brewing terminology as professional craft brewers.

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A-A-A

Acetaldehyde
A chemical biproduct of wort fermentation with the aroma and flavor of green apples.
Acid Rest
An optional step done early in the brewing process by holding the heat of the mash around 95F for several hours to lower the pH of the mash.
Adjunct
Any unmalted grain or other fermentable ingredient used in the brewing process. Rice, corn or other grains can be used as adjuncts as can honey, corn syrups, sorghum and numerous other sources of fermentable carbohydrates.
Aeration
Introduction of air to the wort during brewing.
Alcohol
Ethyl alcohol or ethanol. The colorless primary alcohol constituent of beer, wine and other distilled spirits.
Alcohol by Volume
ABV. A worldwde standard measure of the volume of ethyl alcohol (ethanol) contained in a given volume of an alcoholic beverage expressed as percent of total volume. Chemically, ABV is defined as the number of millilitres of pure ethanol present in 100 ml of solution at 20°C. The number of millilitres of pure ethanol is the mass of the ethanol divided by its density at 20°C, which is 0.79 g/ml. In English units this is the number of fl oz. of pure ethanol present in 3.5 fl oz of solution at 68°F. The number of fl. oz. of pure ethanol is the mass of the ethanol divided by its density at 68°F, which is 0.46 oz/cu in.  Abbreviated as “ABV”, “abv”, or “alc/vol”. 
Alcohol by Weight
ABW. A measurement of the percentage weight of ethyl alcohol per volume of beer. For example,  3.2 percent alcohol by weight equals 3.2 fl. oz. of alcohol per 100 fl.oz. of beer. This measure is always lower than Alcohol by Volume. To calculate the approximate Alcohol by Weight, divide Alcohol by Volume by 1.25. Similarly, to calculate the approximate Alcohol by Volume, multiply Alcohol by Weight by 1.25. Abbreviated as “ABW”, “abw”, or “alc/wt”. 
Ale
Ales are beers fermented with top fermenting yeast (yeast that is applied to the top of the wort during brewing). Ales are typically fermented at temperatures from 14° – 30°C (30° – 86°F) lagers beers and are often served warm.
Ale Yeast
Top fermenting yeasts from the family Saccharomyces Cerevisiae are that are applied to the top of the wort during brewing and which ferment at warm temperatures from 14 °- 30 °C (30 ° – 86 °F) and generally produces rich flavor compounds.
Alpha Acid
One of two primary naturally occurring resins in hops. During wort boiling alpha acids (α acids) are converted to iso-alpha acids, which cause most beer bitterness. During aging, alpha acids oxidize and lessen in bitterness.
Alpha and Beta Amylase
During beer fermentation these enzymes break down starch into fermentable sugars. Different temperatures optimize the fermentation activity for alpha or beta amylase, resulting in different mixtures of fermentable and unfermentable sugars.
Apparent Attenuation
Test used to measure the extent of fermentation. Attenuation refers to the conversion of sugars into alcohol and carbon dioxide during fermentation; the greater the attenuation, the more sugar has been converted into alcohol. Starting with the same wort more attenuated beers are drier and more alcoholic than less attenuated beers. Using a hydrometer to measure, apparent attenuation is equal to the wort’s original gravity minus the sample gravity divided by the original gravity. The resulting percentage is 65% to 80% for most beers; the higher the attenuation the drier and more alcoholic the beer.
Aromatic Hops
Hops that are added later in the boiling process. Shorter amount of time spent in the boil kettle provides more aromatic characteristics and less bittering characteristics from the hops.
Astringency
A combination of beer taste and oral sensation that result from polyphenols. Phenols arise from malt husks and hops stems that polymerise to polyphenols during brewing and beer aging. Polyphenols can include tannins that in high enough concentrations can cause the mouth to pucker.
Attenuation (Final Attenuation)
The reduction in wort specific gravity caused by the yeast consuming wort sugars and converting them into alcohol and carbon dioxide gas through fermentation; the greater the attenuation, the more sugar has been converted into alcohol. Starting with the same wort more attenuated beers are drier and more alcoholic than less attenuated beers. Using a hydrometer to measure, final attenuation is equal to the wort’s original gravity minus the final gravity divided by the original gravity. The resulting percentage is 65% to 80% for most beers; the higher the attenuation the drier and more alcoholic the beer.
Autolysis
A brewing defect which produces beer with a sharp, bitter taste with a meaty and sulphury edge caused by the breakdown of yeast due to overcooking. A beer that has experienced significant autolysis will have a taste and smell like burnt rubber tires and will probably be undrinkable. 
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B-B-B

Barley
A cereal grain derived from the annual grass Hordeum vulgare. Barley is used as a base malt in the production of beer and certain distilled spirits, as well as a food supply for humans and animals.
Balling Scale
The Balling Scale (or simply “°Balling”) is a measurement of the concentration of dissolved solids (mainly sugars) in a brewery wort. The solids concentration can be measured most simply by using a hydrometer, an instrument used for measuring the specific gravity of a liquid.
Barrel
1) A standard U.S. measure of 31 gallons. Abbreviated as “BBL”.
2) A wooden vessel that is used to age/condition beer. Brewer’s barrels can be brand new or used previously to store beer, wine or spirits.
Beta Acid
One of two primary naturally occurring soft resins in hops. During wort boiling beta acids (β acids) contribute very little to the bitterness of beer and during aging they have some preservative qualities.
Bitterness
The bitterness of beer comes from hops used in brewing from compounds such as humulones, or alpha acids. During the brewing process, humulone isomerizes to form cis- and trans- isohumulone which are responsible for the bitter taste of the beer.
Bitterness Units (BU)
See International Bitterness Units (IBU).
Bittering Hops
Hops added early in the boiling stage of the brewing process. The longer hops are boiled, the more bittering characteristics will come from those hops.
Blending
The mixing together of beer from different batches to create a final product. Often used to keep “Brand Name” beers consistent from batch to batch.
Body
Taken as a whole, a beer’s consistency, thickness, mouth-filling properties and sensation of palate fullness ranging from thin to full-bodied.
Boiling
A critical step in the brewing process during when wort (unfermented beer) is boiled inside the brew kettle. During the boiling, hops are added to achieve bittering, hop flavor and hop aroma in the finished beer. Boiling also removes volatile compounds such as dimethyl sulfide from wort and coagulates excess or unwanted proteins. Boiling also sterilizes the beer as well as ending the enzymatic conversion of proteins to sugars.
Bottle Conditioning
Naturally carbonating beer in the bottle as a result of fermentation of additional wort or sugar intentionally added during bottling.
Bottom Fermentation
Fermentation characterized by yeast cells that sink to the bottom of the fermentation vessel. Lager yeast is considered to be bottom fermenting; ale yeast is considered to be top fermenting. Beers brewed using bottom fermentation are commonly called “lagers”. 
Brettanomyces
Brettanomyces are a non-spore forming single cell genus of yeasts in the family Saccharomycetaceae. It is often colloquially referred to as “Brett”. The genus name “Dekkera” is typically used interchangeably with “Brettanomyces” to describe the single cell spore forming varieties of the yeast. Single-celled yeasts that ferment sugar are important to the beer and wine industries due to the variety of sensory flavors they produce. 
Brewery
A building, property, or company that is involved in the production of beer.
Brewhouse
1) When referring to the brewing process the vessels and tanks (mash tun, lauter tun, brew kettle, hot liquor tank, etc.) where malted grain is transformed into fermentable wort. Also called “hot side”.
2) A brewery. A facility where beer is brewed.
Brew Kettle
One of the vessels used in the brewing process in which the wort (unfermented beer) is boiled.
Bung
A conical sealing stopper, usually made of wood, rubber or plastic, pounded into the mouth of a cask or older style kegs using a bung starter to seal them. 
Bung Hole
The round hole in the side of a cask or older style keg, through which the keg is filled with beer and then sealed with a bung.
Burton Snatch
The whiff of sulfur on a freshly poured beer. The aroma is particularly associated with beers originally brewed in Burton-on-Trent, England. The sulfur smell originates from the presence of sulfate ions in Burton’s natural water supply. The high levels of sulfate in Burton waters (up to 800 ppm) bring a hard, dry mineral edge to the bitterness of beers brewed there making the water ideal for the production of pale ales. The term is now somewhat antiquated. 
Byproducts
Desirable and undesirable compounds that result from fermentation, mashing, and boiling.
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C-C-C

Calcium Carbonate
CACO3. A mineral common in water of different origins. Commonly known as “chalk”, it is sometimes added during beer brewing to increase calcium and carbonate content.
Calcium Sulfate
CASO4. Mineral common in water of different origins. Commonly known as “gypsum”, it is sometimes added during beer brewing to increase calcium and sulfate content.
Carbohydrates
Carbon-based organic compounds including sugars and starches, many of which are suitable as food for the yeast and bacteria used in brewing.
Carbon Dioxide
CO2. The gaseous by-product produced when yeast eats carbohydrates. Carbon dioxide is what gives beer its carbonation (bubbles).
Carbonation
Introducing carbon dioxide into beer by
1 – Injecting carbon dioxide directly into finished beer
2 – Adding sugar to fermented wort prior to packaging, causing secondary fermentation in the bottle (bottle conditioning)
3 – Adding young fermenting beer to finished beer, causing secondary fermentation in the fermentation vessel (kraeusening)
4 – Pressurizing a fermentation vessel to capture naturally produced carbon dioxide;
Carboy
A large glass, plastic or earthenware bottle.
Caryophyllene
One of the four essential oils (caryophyllene, farnesene, humulene and myrcene) made in the hops plant, Humulus Lupulus.
Cask
A barrel-shaped container for holding beer. Originally made of wooden staves held together with iron bands, now most widely constructed using stainless steel and aluminum.
Cask Conditioning
Storing unpasteurized, unfiltered beer in cool cellars (48-55°F) for several days while natural carbonation proceeds.
Catwalk
A platform, often with stairs, that allows access to the top of the brewhouse tanks.
Cellaring
Storing or aging beer at a controlled temperature to allow the beer to mature.
Chill Haze
Upon chilling, the hazy or cloudy appearance caused when the proteins and tannins naturally found suspended in finished beer combine into particles large enough to reflect light or become visible.
Clean In Place
CIP. The process of cleaning brewing equipment without disassembly or having to transport it to a different location. Typically, a spray ball is used within the tank to coat all the interior surfaces with the chemicals then to thoroughly rinse the tank. 
Closed Fermentation
Fermentation without oxygen under closed, anaerobic conditions to reduce the risk of contamination and oxidation.
Cold Break
The precipitation and settling of proteins and tannins from the beer during wort cooling.
Color
The hue or shade of a beer, primarily derived from ingredients in beer. Beers made with caramelized, toasted, roasted malts or roasted grains will exhibit increasingly darker colors. The color of a beer does not equate to alcohol level, mouthfeel or calories in the beer.
Cold Crashing
Rapidly lowering the temperature of beer to near freezing after fermentation before packaging. Cold crashing clarifies the beer by precipitating remaining yeast and other particles out of the beer leaving it clear.
Cold Liquor Tank
A large storage tank for cold water used during brewing. 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”.
Cold Side
The ‘cold-side’ is everything that happens in the brewery without the addition of heat (yeast handling, fermentation, carbonation, clarifying, packaging, etc) 
Conditioning
After initial fermentation the step in the brewing process where beer is matured or aged.
Cracking
The grinding of malt, other grains or adjuncts into grist to facilitate the extraction of sugars and other soluble substances during mashing. (See Milling)
Crashing
See Cold Crashing
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D-D-D

Decoction MashA method of mashing that raises the temperature of the mash by removing a portion of the mash from the mash tun, boiling it externally then returning it to the mash tun. Often used multiple times in certain mash boiling programs.
Degrees PlatoSee Plato Gravity Scale
DextrinDextrins are a group of low-molecular-weight complex, tasteless carbohydrates produced by the hydrolysis of starch or glycogen. Dextrins are produced in brewing during malting and mashing. Dextrins contribute to the gravity and the body of beers. Some dextrins may remain undissolved in the finished beer, giving it a malty sweetness.
DextroseDextrose is a simple sugar formed from one molecule of glucose. It is the most common naturally occurring sugar and it can be used in brewing beer.
DiacetylAn organic compound characterized by the aroma and flavor of butter. Low levels of diacetyl can be acceptable in some styles of beer but at higher levels it is often an unwanted or accidental flavor defect.
DiastaticEnzymes that are created as grain sprouts. These enzymes convert starches to sugars which yeast eat during fermentation.
Dimethyl SulfideDMS. An organic compound characterized by the aroma and flavor of cooked vegetables such as corn. Low levels of DMS can impart a sweet aroma that is acceptable in some styles of beer but it at higher levels it is often an unwanted or accidental flavor defect.
Dimpled JacketA tank glycol jacket with “dimples” which adds to the structural integrity of the jacket and through which a chilled solution of propylene glycol is pumped to cool the tank contents. See Glycol Jacket.
DoughballDoughballs form during mashing when crushed grain begins to cluster and clump together in the water in the mash tun. Roughly analogous to lumps that form when making Cream-Of-Wheat, doughballs typically form due to incorrect ingredient ratios or poor ingredient mixing. Grist hydrators, mash paddles, and/or rake and plows with proper ingredient ratios help prevent doughballs from forming during mashing.
Draught BeerBeer sold and served from kegs rather than from cans, bottles or other containers is usually called draught beer. 
Dry HoppingThe addition of hops late in the brewing process to increase the hop aroma of a finished beer without significantly affecting its bitterness. During boiling dry hops may be added to the wort in the kettle, whirlpool or hop back, or hops can be added to beer during primary or secondary fermentation or even later in the process.
Dual Purpose HopsHops that provide both bittering and aromatic properties.
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E-E-E

Endosperm
The starch-containing portion of the barley grain.
Essential Hop Oils
Essential hop oils provide the aromatic and flavor compounds that are associated with the addition of various varieties of hops.
Esters
Volatile organic compounds that form during fermentation through the interaction of acids with alcohols and which contribute to the fruity aroma and flavor of beer.
Ethanol
Ethyl alcohol. The colorless primary alcohol constituent of beer, wine and other distilled spirits.
European Brewery Convention
EBC. An analytical method that brewers use to objectively measure and quantify the color of a beer. To measure EBC, a photometer is used to measure the attenuation of deep blue light (430nm wave length) when it is passed through a 1CC sample of the beer. All sorts of ugly optical physics calculations are then required but the bottom line is that the higher the EBC is, the darker the beer. In beer, EBC ranges from as low as 4 (lightest lagers) to as high as 80 (porters, stouts) and beyond. Standard Reference Method (SRM) and European Brewery Convention (EBC) are similar in process and differ primarily in how measurement results are expressed: EBC=SRM x 1.97 or SRM=EBC x 0.508. See Standard Reference Method.
Export
Beer produced for the express purpose of exportation rather than for domestic consumption. For example, export-style German lagers or export-style Irish stouts.
Extract Beer
Beer made with malt extract as opposed to one made from barley malt or made from a combination of malt extract and barley malt.
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F-F-F

Farnesene
One of the four essential oils (caryophyllene, farnesene, humulene and myrcene) made in the hops plant, Humulus Lupulus.
Fast Crashing
See Cold Crashing
Fermentable Sugars
Sugars such as glucose, fructose, sucrose, maltose, and maltotriose, that are consumed by yeast cells and produce approximately equal parts of ethyl alcohol and C02.
Fermentation
The chemical conversion of fermentable sugars by yeast cells into approximately equal parts of ethyl alcohol and carbon dioxide gas. The two most commonly used methods of fermentation in brewing are “top fermentation”, which produces ales, and “bottom fermentation”, which produces lagers.
Fermentation Lock
A one-way valve, often made of glass or plastic that is fitted onto a fermenter and allows carbon dioxide gas to escape from the fermenter while excluding ambient wild yeasts, bacteria and contaminants.
Fermenter
Fermenters are specialized tanks designed to precisely control temperature and maintain the optimal conditions for beer fermentation; fermenters can be a variety of sizes with a conical-bottom design highly recommended to allow for easier yeast harvesting.
Filtration
At the end of the brewing process passing beer through a filter to clarify the beer by removing solid particles suspended in the beer.
Final Gravity
The specific gravity of a beer as measured with a hydrometer when fermentation is complete (when all desired fermentable sugars have been converted to alcohol and carbon dioxide gas). Synonyms:  FSG, Final Specific gravity; Final SG; Finishing Gravity; Terminal Gravity.
Fining
Prior to filtering adding clarifying agents to beer during secondary fermentation to hasten the precipitation of suspended matter, such as yeast, proteins or tannins. Commonly used clarifying agents include isinglass, casein, gelatin, silica gel and Polyvinyl Polypyrrolidone (PVPP).
Flocculation
The clumping together and settling of particles suspended in wort or beer. During brewing, protein and tannin particles will flocculate out of the kettle or fermenter during a hot or cold break. At the end of fermentation, yeast cells will flocculate to varying degrees thereby affecting final fermentation as well as the filtration of the resulting beer.
Forced Carbonation
Carbonation by forcing CO2 at high pressure into beer in a sealed container. Under high pressure, the CO2 is absorbed into the beer.
Fresh Hopping
The addition of undried, freshly harvested hops at different stages of the brewing process. Fresh hopping can add unique flavors and aromas to beer that are not normally found when using dried and processed hops.
Fructose
Fructose is a simple sugar found in honey and fruit. It is a commonly naturally occuring sugar and it can be used in brewing beer.
Fusel Alcohol
A family of alcohols, which can result from fermentation at excessively high temperatures. Fusel alcohols can impart harsh or solvent-like flavor characteristics commonly described as “lacquer” or “paint thinner”.
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G-G-G

Germination
Growth of a grains as they produce a rootlets and acrospires.
Glycol
A glycol is an alcohol with two hydroxyl groups on adjacent carbon atoms. The two main types of glycol, ethylene glycol and propylene glycol, are industrial anti-freezes. Ethylene glycol is highly toxic and in food applications such as brewing propylene glycol is used. 
Glycol Chiller
A glycol chiller is a brewery cooling unit that utilizes propylene glycol or a mix of propylene glycol and water to rapidly extract excess heat from brewing processes and dissipate it in a heat exchanger or refrigeration system. Brewery glycol chillers are necessary to provide the close temperature control required to produce brewed products of the highest quality.
Glycol Jacket
A glycol jacket is attached to the outside of a tank. The glycol jacket contains cavities through which a mix of propylene glycol and water is pumped to chill the contents of the tank. Glycol jackets can be permanently attached to the tank or removable. They often contain “dimples” to add to the structural integrity of the jacket. See Dimpled Jacket
Grain Auger
A piece of brewery equipment, sometimes called a “screw conveyor”, used to transfer uncracked grain from a storage hopper to the grain mill for grinding (cracking), cracked grain from a grain mill to a grist case for storage and ultimately from a grist case to a brewhouse for brewing. 
Grain Mill
A piece of brewery equipment for the grinding of malt, other grains or adjuncts into grist to facilitate the extraction of sugars and other soluble substances during mashing. 
Grainy
A taste flaw that can cause beer aromas and flavors of hay, wet grain, nuttiness and wortiness. 
Grant
A small open-air wort collection vessel placed between the lautering vessel and the wort brew kettle. Traditionally, a grant had three purposes: (a) to avoid a potential vacuum in the lauter or mash/lauter tun during wort pumping to avoid causing turbid worts or stuck mashes; (b) to allow the brewer to assess wort clarity and wort flow and (c) in larger systems with multiple lauter tun outlets, to determine whether all parts of the grain bed were flowing sufficiently or required measures to improve flow-through.
Grist
Malt and grains ground to size and ready for mashing.
Grist Case
Grist cases are cracked grain storage vessels. Located between the grain mill and the brewhouse, the grist case is the intermediary stop for grain after grinding (cracking), prior to introduction into the mash tun.
Grist Hydrator
Grist hydrators wet crushed grain as it is transfered into the mash tun by the grain auger. Grist hydrators are used to minimize doughball formation in the mash tun. See Doughball.
Growler
A container used by craft brewers to dispense beer to customers. Growlers are typically made of dark glass (to prevent beer from becoming lightstruck) and come in various sizes; typical is 1/2 gallon (64 fl. Oz.) or 2 L.
Gruit
An old-fashioned mixture of herbs used for bittering and flavoring beer that was popular before the extensive use of hops. “Gruit” or “gruit ale” may also refer to beer produced using gruit.
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H-H-H

Hand Pump
A  pump used to pressurize a keg or cask to dispense draught beer. The use of a hand pump allows the draught beer to be served without the use of pressurized carbon dioxide.
Head Retention
The stability of beer foam as measured, in seconds, by time required for a 1-inch foam collar to collapse.
Heat Exchangers
After wort boiling in the brew kettle the heat exchanger is used to cool hot wort before fermentation. Heat exchangers quickly transfer and lower the temperature of wort through a series of stacked plates. Typically, brewers need to transfer hot wort from the boil kettle into the fermenters. In order to do so, the wort is passed through one side of the heat exchanger, while cold water passes through the other side to lower the temperature as required.
Homebrewing
The art of making great craft beer in small batches at home. A single person is legally allowed to brew up to 100 gallons of beer annually for personal enjoyment and up to 200 gallons in a household of two persons or more of legal drinking age.
Hot Liquor Tank
A large storage tank for hot water used during brewing. 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”.
Hopback
A chamber between the brew kettle and wort chiller. Hops are added to the chamber, the hot wort from the brew kettle is run through it and then immediately cooled in the wort chiller before entering the fermentation chamber. Hopbacks utilize a sealed chamber to facilitate maximum retention of volatile hop aroma compounds that would normally be driven off when the hops contact the hot wort.
Hopback Grant
A single vessel between the brew kettle and the wort chiller combining the functions of a hopback and grant.
Hops
A perennial climbing vine, also known by the Latin botanical name Humulus Lupulus, used to flavor beer. Over one hundred varieties of hops are cultivated around the world.  Apart from contributing its characteristic bitterness, hops impart aroma and flavor while inhibiting the growth of bacteria in wort and beer. Hops are added at the beginning (bittering hops), middle (flavoring hops), and end (aroma hops) of the wort boiling stage, or even later in the brewing process (dry hops). Hops have been used to flavor beer as far back as Egypt around 600 BC. Hops were cultivated in Germany as early as 300AD. Prior to the use of hops beer was flavored with herbs and spices such as juniper, nutmeg, cloves and other herbs or spices.
Hopping
Adding hops to un-fermented wort or fermented beer.
Hot Break
The foam that forms and rises right before the wort boils. Once boiling it will collect into clumps (flocculation) and eventually sink to the bottom.
Hot Side
The vessels and tanks (mash tun, lauter tun, brew kettle, hot liquor tank, etc.) where malted grain is boiled and processed to transform it into fermentable wort.
Human Machine Interface
HMI. A user interface or dashboard that connects a person to a machine, system, or device. HMI allows for brewers to accurately monitor and control temperatures, recipes, and more for optimum repeatable brewing performance.
Humulene
One of the four essential oils (caryophyllene, farnesene, humulene and myrcene) made in the hops plant, Humulus Lupulus.
Hydrometer
A hydrometer is an instrument used for measuring the relative density of liquids based on the concept of buoyancy. They are typically calibrated and graduated with one or more scales such as specific gravity. Using a beer hydrometer to measure the Original Gravity of your wort and the Final Gravity of your beer helps you determine the ABV and give you valuable insight into the health of your brewing yeast and the effectiveness of your overall beer brewing process. 
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I-J-K

Insulation
Insulating tanks is essential for minimizing heat loss through a boil kettle or maintaining controlled cool temperatures for your fermenters. Insulated tanks are energy-saving and long term will help lower the cost of brewing operations. 
Immersion Chiller
A wort chiller most commonly made of copper tubing filled with cold water that is submerging into hot wort before fermentation.
Infusion Mash
A method of mashing which achieves target mashing temperatures by the addition of heated water at specific temperatures.
Innoculate
The introduction of yeast into wort to begin the fermentation process and make beer.
Insulation Jacket
A removable or permanent jacket of insulation material which maintains controlled temperatures for tanks. See Insulation.
International Bitterness Units (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.
Irish Moss
Beer clarifier made from seaweed that helps to precipitate proteins in the kettle by facilitating the hot break.
Isinglass
A gelatinous substance sometimes added to fermented beer to help clarify and stabilize the finished beer.
Keg
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.
Keg Washer
A keg washer cleans stainless steel kegs of beer and beverages by sequentially rinsing, washing, sterilizing, and pressurizing the keg. Most keg washers are semi-automatic, but manual and fully automatic keg washers are also common. Also, many keg washers can clean one, two, three or more kegs at one time.
Kilning
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.
Kraeusen
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.
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L-L-L

Lace
The delicate pattern of foam sticking to the sides of a glass of beer once it has been partly or totally emptied. Synonym: Belgian lace.
Lactobacillus
Lactobacillus is a microorganism most often considered to be a beer spoiler that can convert unfermented sugars found in beer into lactic acid souring the taste. Some brewers introduce small amounts of Lactobacillus intentionally into finished beer in order to add a desirable acidic sourness to the flavor profile of certain brews.
Lager
Lagers are beers that are fermented with bottom-fermenting yeast at colder temperatures. Lagers are most often associated with crisp, clean flavors and are traditionally fermented and served at colder temperatures than ales.
Lager Yeast
Bottom fermenting yeasts from the family Saccharomyces Pastorianus that ferments in cooler temperatures (45-55 F) and often lends to a crisper taste.
Lagering
Lagering is the producction of any beer that is fermented with bottom-fermenting yeast at colder temperatures.
Lagering Tank
A large storage tank, often horizontal, used for long term storage of beer while it is lagering.
Lauter Tun
A large brewing vessel fitted with a slotted bottom in which the mash is allowed to settle and sweet wort is separated from the grains through a straining process. In some smaller breweries, the mash tun can be used for both mashing and lautering. (See Mash Tun/Lauter Tun Combination)
Lautering
Separating the sweet wort (pre-boil) from the spent grains in a lauter tun or with other straining apparatus.
Lightstruck
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.
Liquor
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”.
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M-M-M

Magnum
A 1.5L  (1,500ml) bottle of beer. Synonym: Magnum Bottle
Malt
Barley that has been steeped in water, germinated, and dryed to convert the soluble substances and sugars present in the grain to fermentable malt.
Malt Beer
A beer made entirely from barley malt mash without the addition of adjuncts, sugars or additional fermentables.
Malting
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.
Malt Processed
Grain that has been processed into malt.
Malt Extract
A thick syrup or dry powder prepared from malt and sometimes used in brewing.
Maltose
Maltose, also known as “maltobiose” or “malt sugar”, is a disaccharide sugar formed from two molecules of glucose. It is the most abundant fermentable sugar used in brewing beer.
Manifold
A component of brewery plumbing that allows the contents of mash tuns, lauter tuns, brew kettles, etc. to be routed from one tank to another through the use of valves and pumps.
Manway
A sealed port in the side or top of a tank that can be opened to allow access to the interior of the tank.
Mash
A mixture of ground malt (and possibly other grains or adjuncts) and hot water that forms the sweet wort after straining.
Mash Paddle
A simple but important metal or wooden manual stirrer essential to mixing in your brewing water and breaking up doughballs during the mashing process. 
Mash Tun
The vessel in which grist is soaked in water and heated in order to convert the starch to sugar and to extract the sugars, colors, flavors and other solubles from the grist. In some smaller breweries, the mash tun can be used for both mashing and lautering. (See Mash Tun/Lauter Tun Combination)
Mash Tun/Lauter Tun Combination
The vessel in which grist is soaked in water and heated in order to convert the starch to sugar and to extract the sugars, colors, flavors and other solubles from the grist. The mash is allowed to settle and sweet wort is removed from the grains through a straining process. 
Mashing
Mixing grist (crushed malt, other grains and adjuncts) with hot water to convert grain starches to fermentable sugars that will form the flavors and characteristics of the beer being brewed. Mashing also helps control haze-forming proteins. Mashing requires several hours and produces wort, a sugar-rich liquid to which yeast is added for fermentation.
Mashing Out
Halting enzymatic activity to prevent further conversion of starches to sugars by raising the mash temperature to 165-170°F (75-77°C ). 
Mead
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.
Milling
The grinding of malt, other grains or adjuncts into grist to facilitate the extraction of sugars and other soluble substances during mashing. The grain must be crushed to medium-sized meal rather than to flour consistency. It is important that the grain husks remain intact when the grain is milled because so they can later act as a filter aid during lautering.
Modification
Physical and chemical changes in grains resulting from malting, especially the development of enzymes that modify the grain’s starches into sugars during mashing, and also the physical changes that render the sugars found in grain kernels more available to the brewing process.
Modified Malts
The length of the germination process and how many of the grain’s internal malt structures and compounds have already been broken down.
Mouthfeel 
Taste, fullness, carbonation, bitterness, aftertaste, etc. taken as a whole when drinking a beverage.
Musty
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.
Myrcene
One of the four essential oils (caryophyllene, farnesene, humulene and myrcene) made in the hops plant, Humulus Lupulus.
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N-N-N

Natural Carbonation
Adding sugar to beer in a container and then sealing. Fermentation restarts as the yeast eats the new sugar and releases CO2 which then carbonates the beer.
Nitrogen
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. So drink up!
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. 
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O-O-O

Oasthouse
Building or facility where hops are dried and aged after harvesting
Original Gravity
Specific gravity of wort at the start of fermentation. Also OG, original specific gravity, starting gravity, starting specific gravity.
Oxidation
Chemical reaction of reagents with oxygen. Oxygen is one of the most reactive of all chemicals.
Oxidized
A taste flaw resulting from undesired interaction of oxidation in the beer after brewing is complete that can give beer stale aromas and flavors of wet paper or cardboard.
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P-Q-R

Package
Containers filled with beer for marketing it to the public. Packaged beer is generally sold in bottles and cans of various sizes.
Palate
The areas on the inside of your mouth that are associated with how foods or beverages taste to you.
Pediococcus
A strain of lactic acid bacteria. Often called “pedio” by brewers, it is sometimes used in the production of certain Belgian beers. Certain Pediococcus strains can produce diacetyl, which results in a buttery or butterscotch aroma and flavor in beer. While sometimes desireable in small doses, it is usually considered to be a flavor defect.
pH
Abbreviation used to express acidity and alkalinity in liquid solutions. Represented on a logarithmic scale ranging from 1-14, with 1 being the most acidic, 7 being neutral and 14 being the most alkaline. Beer is acidic and ranges from 3.0.-6.0 pH with 3.3-5.5 pH being the taste range which most people prefer.
Phenols
Phenols are a broad class of chemical compounds which are by-products of fermentation and which are detectable in both the aroma and taste of finished beer. Phenolic flavor and aromatic attributes include cloves, herbs, medicines and others. Some phenolic flavors and aromas are acceptable or even desirable in certain beer styles such as German or Belgian wheat beers where the phenol compounds are a result of the yeast used. Higher concentrations of phenols in beer are a taste defect often due to contaminated brewing water, infection of the wort by bacteria or wild yeasts, inadequate cleaning and rinsing of brewing equipment, etc. 
Pitching
Commencing fermentation by adding yeast to the wort once it has cooled down to desirable temperatures.
Plato Gravity Scale
Degrees Plato (°P) An empirically derived hydrometer scale to measure the density of beer wort in terms of percentage of extract by weight.
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”.
Priming
Adding small amounts of fermentable sugars to fermented beer to induce renewed fermentation in the bottle or keg and thus carbonate the beer.
Proof
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. 
Punt
The hollow indentation at the bottom of some bottles to strengthen the bottle. Also called a “kick up”
Quaff
To drink deeply.
Racking
Transferring beer from one vessel to another, especially into final packages or kegs.
Racking Port
A port in the side of a vessel, normally sealed closed, which can be used to transfer beer from the vessel.
Rake and Plow
Hardware for automatic stirring of mash in the mash tun and lauter tun.
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.
Reinheitsgebot
The German beer purity law decreed in 1516 by Duke Wilhelm IV of Bavaria, stating that beer may only contain water, barley and hops. Yeast was added in 1906 after its role in fermentation was discovered by Louis Pasteur.
Residual Sugar
Any sugar remaining in the beer that the yeast did not consume during fermentation.
Resin
The gummy organic substance produced by certain plants and trees. Humulone and lupulone, for example, are bitter resins that occur naturally in the hop flower.
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S-S-S

Saccharification
The breaking down of complex carbohydrates such as starches into fermentable simple sugars, primarily maltose.
Saccharomyces
The genus of single-celled yeasts that ferment sugar and are used in the making of alcoholic beverages. Yeasts of the species Saccharomyces Cerevisiae  are commonly used in brewing ales (See Ale Yeast) and Saccharomyces Pastorianus are commonly used in brewing of lager beers (See Lager Yeast).
Screw Conveyor
See Grain Auger
Secondary Fermentation
1) The second, slower stage of fermentation for top fermenting beers which can last from a few weeks to many months, depending on the type of beer.
2) Restarting fermentation in bottles or casks by priming with fermentable sugar or by adding fresh yeast. (See Priming)
Sediment
The solid byproducts of brewing and fermentation that settle and accumulate at the bottom of fermenters, conditioning vessels and bottles of bottle-conditioned beer.
Session Beer
A beer not defined by style category, flavor or aroma but instead primarily by refreshment and drinkability suitable for drinking multiple servings in a sitting. These are generally lighter beers with ABV in the 3.2% to 5% range.
Skunking, Skunked
See Lightstruck
Solvent-Like
Flavor and aromatic defect resulting in a taste and scent similar to acetone or lacquer thinner. Ecccccch. Can be caused by fermentation at temperatures that were too high.
Sorghum
A cereal grain from various grasses (Sorghum vulgare) which can be used to make beer. Sorghum beers are popular in Africa and there is also a specialty niche of sorghum beers especially for those who are gluten intolerant.
Sour
A taste and aroma perceived to be acidic and tart. Acceptable or even desirable in minute quantities in some sour beers, too much is considered a flavor defect. If not intentionally introduced by the brewer, sometimes the result of bacterial contamination from wild bacteria such as lactobacillus and pediococcus.
Sparging
Spraying the spent mash grains with hot water at the end of lautering to recover any remaining liquid malt sugar and extract from the grain husks. See Lautering.
Specific Gravity
The ratio of the density of a liquid solution to the density of pure water. Specific gravity is measured with a hydrometer and it is unitless because it is expressed a ratio of two densities. For example, a specific gravity of 1.10 would be a solution 10% more dense than pure water. Specific gravity is measured at several points in the brewing process to determine how much dissolved sugars are present in the processing wort or beer. See also Original Gravity and Final Gravity.
Spray Ball
An element of Clean-In-Place systems that is used to spray cleaners in tanks then rinse them out. See Clean-In-Place.
Standard Reference Method
SRM. An analytical method that brewers use to objectively measure and quantify the color of a beer. To measure SRM, a photometer is used to measure the attenuation of deep blue light (430nm wavelength) when it is passed through a 1CC sample of the beer. All sorts of ugly optical physics calculations are then required but the bottom line is that the higher the SRM is, the darker the beer. In beer, SRM ranges from as low as 2 (lightest lagers) to as high as 45 (porters, stouts) and beyond. Standard Reference Method (SRM) and European Brewery Convention (EBC) are similar in process and differ primarily in how measurement results are expressed: EBC=SRM x 1.97 or SRM=EBC x 0.508. See European Brewery Convention.
Steeping
The soaking of grain in liquid (usually water) to extract flavors.
Step Infusion
A mashing method where very hot water is added to raise the temperature of the mash, the mash is then stirred to stabilizing the mash at the target step temperature and the process is repeated for each additional step.
Sucrose
Sucrose is a disaccharide sugar formed from one molecule of fructose and one molecule of glucose. Found in fruits, beet sugar and cane sugar, it can be used in brewing beer.
Sulfur Dioxide
The undesirable aroma of rotten eggs.  Can be a by-product of some yeasts or by a beer being exposed to light and becoming light struck. See Light Struck.
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T-T-T

Tannins
A group of polyphenol organic compounds contained in certain cereal grains and other plants including hops. In finished beers, tannins tend to manifest themselves as an astringent or bitter flavor. In controlled amounts, this can be desirable in some beer varieties but too much is definitely a flavor defect. Tannins can also cloud the finished beer with a permanent haze or a chill haze (haze that only shows up when the beer is chilled).
Taste
The subjective descriptions of temperature, flavor and texture. In beer tasting, descriptors tied to beer’s taste include:  Cold/Hot, Dry/Tannic/Astringent, Sweet/Salty/Sour, Thin/Heavy, Smooth/Harsh, etc.
Temperature Rests
Temperature Rests hold the temperature of the brewing wort in a specific range for hours or even days during the beer making process to allow the brewer to adjust fermentable sugar profiles and influence characteristics of the final beer.
Top Fermentation
Fermentation characterized by yeast cells which rise to the top of the fermentation vessel.  Ale yeast is considered to be top fermenting. Lager yeast is considered to be bottom fermenting; Beers brewed using top fermentation are commonly called “ales”. 
Trub
Sedimentary wort particles resulting from the precipitation of proteins, hop oils and tannins during the boiling and cooling stages of brewing that settle to the bottom of the brewing vessel. Should not be left in contact with the word.
Turbidity
Degrees of hazy, murky appearance caused by sediment in suspension in the beer; the more sediment the hazier the beer.
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U-V

Unitanks
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.
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.
Volumes of C02
The measurement of CO2  dissolved in beer and an indication of the carbonation level. A rather bizarre measurement, one “volume” of CO2 is the volume of space that the CO2 would take up at an STP (Standard Temperature and Pressure – usually 32° F and one atmosphere) if removed from the beer. In other words, if a 15.5-gallon keg of beer contained two volumes of CO2, the CO2 by itself would occupy twice the space the beer takes up or 31 gallons of CO2. Weird, huh? In practice, most commonly available beers typically contain 1-4 volumes of CO2 with 2-2.5 volumes being the most common.
Vorlauf
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.
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W-X-Y-Z

Water
One of the four core ingredients in beer. Some beers are made up by as much as 90% water. Some beer brewers refer to the water used for mashing and brewing as “liquor”, especially natural or treated water.
Wet Hopping
Addition freshly harvested hops that have not yet been dried at different stages during brewing. Wet hopping can add unique flavors and aromas that are not normally found when using hops that have been dried and processed.
Whirlpool
1) A method of collecting hot break material in the center of the kettle by stirring the wort until a vortex is formed.
2) A specialized brewhouse tank where boiled wort is precisely swirled to precipitate solids and accumulate them in a neat cone called a trub pile.
Wort
The bittersweet solution obtained by mashing the malt and boiling in the hops which is then fermented to make beer.
Yeast
Living single-cell organisms that convert sugars into alcohol and carbon dioxide gas during fermentation.
Yeast Cake
Living yeast cells are compressed with starch into a cake which will dissolve in liquid wort to start beer fermentation. Yeast is vital for the fermentation process. They also provide fizz and are necessary in the bottle to build natural effervescence.
Yeast Enzymes
Enzymes within yeast cells that act as catalysts for a specific activity during the fermentation process. There are numerous yeast enzymes that are known to be active during the brewing of beer.
Yeast Pitching
Adding living yeast to the cooled wort to start beer fermentation.
Zymurgy 
The study or practice of fermentation in brewing, winemaking, or distilling.
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Portland Kettle Works (“PKW”) is the premier American manufacturer of stainless-steel brewing and beverage equipment for Craft Beer, Wine, Kombucha, Cold Brew Coffee, Pharmaceutical and Dairy applications plus Mixing Tanks, and accessories for these industries.


Portland Kettle Works was founded in 2011 to build the highest quality stainless steel brewing and beverage equipment applications. Since then we have built and installed over 375 breweries worldwide. Our craft brewers are among the best of the best and they have the gold, silver and bronze medals to prove it. If you’re serious about craft brewing as a business, contact us and we can help you, too. And if you’re located in Mexico or Latin America, click here to visit our Spanish language site.