Acrospire |
The beginnings of the plant shoot in germinating barley. |
Adjunct |
Any non-enzymatic fermentable. Adjuncts include: unmalted cereals
such as flaked barley or corn grits, syrups, and sugars. |
Aerate |
To mix air into solution to provide oxygen for the
yeast. |
Aerobic |
A process that utilizes oxygen. |
Aldehyde |
A chemical precursor to alcohol. In some cases, alcohol
can be oxidized to aldehydes, creating off-flavors. |
Ale |
A beer brewed from a top-fermenting yeast with a
relatively short, warm fermentation. |
Aleurone Layer |
The living sheath surrounding the endosperm of a barley
corn, containing enzymes. |
Alkalinity |
The condition of pH between 7-14. The chief cause of
alkalinity in brewing water is the bicarbonate ion (HCO3-1). |
Alpha Acid Units (AAU) |
A homebrewing measurement of hops. Equal to the weight
in ounces multiplied by the percent of alpha acids. |
Amino Acids |
An essential building block of protein, being comprised
of an organic acid containing an amine group (NH2). |
Amylase |
An enzyme group that converts starches to sugars,
consisting primarily of alpha and beta amylase. Also referred to as the
diastatic enzymes. |
Amylopectin |
A branched starch chain found in the endosperm of
barley. It can be considered to be composed of amylose. |
Amylose |
A straight-chain starch molecule found in the endosperm
of barley. |
Anaerobic |
A process that does not utilize oxygen or may require
the absence of it. |
Attenuation |
The degree of conversion of sugar to alcohol and CO2. |
Autolysis |
When yeast run out of nutrients and die, they release
their innards into the beer, producing off-flavors. |
°Balling, °Brix, or °Plato |
These three nearly identical units are the standard for
the professional brewing industry for describing the amount of available
extract as a weight percentage of cane sugar in solution, as opposed to
specific gravity. Eg. 10 °Plato is equivalent to a specific gravity of
1.040. |
Beer |
Any beverage made by fermenting a wort made from malted
barley and seasoned with hops. |
Beerstone |
A hard organo-metallic scale that deposits on
fermentation equipment; chiefly composed of calcium oxalate. |
Biotin |
A colorless crystalline vitamin of the B complex, found
especially in yeast, liver, and egg yolk. |
Blow-off |
A type of airlock arrangement consisting of a tube
exiting from the fermenter, submerging into a bucket of water, that
allows the release of carbon dioxide and removal of excess fermentation
material. |
°Brix, °Balling, or °Plato |
These three nearly identical units are the standard for
the professional brewing industry for describing the amount of available
extract as a weight percentage of cane sugar in solution, as opposed to
specific gravity. Eg. 10 °Plato is equivalent to a specific gravity of
1.040. |
Buffer |
A chemical species, such as a salt, that by
disassociation or re-association stabilizes the pH of a solution. |
Cellulose |
Similar to a starch, but organized in a mirror aspect;
cellulose cannot be broken down by starch enzymes, and vice versa. |
Cold Break |
Proteins that coagulate and fall out of solution when
the wort is rapidly cooled prior to pitching the yeast. |
Conditioning |
An aspect of secondary fermentation in which the yeast
refine the flavors of the final beer. Conditioning continues in the
bottle. |
Decoction |
A method of mashing wherein temperature rests are
achieved by boiling a part of the mash and returning it to the mash tun. |
Dextrin |
A complex sugar molecule, left over from diastatic
enzyme action on starch. |
Dextrose |
Equivalent to Glucose, but with a mirror-image
molecular structure. |
Diastatic Power |
The amount of diastatic enzyme potential that a malt
contains. |
Dimethyl Sulfide (DMS) |
A background flavor compound that is desirable in low
amounts in lagers, but that at high concentrations tastes of cooked
vegetables. |
Endosperm |
The nutritive tissue of a seed, consisting of
carbohydrates, proteins, and lipids. |
Enzymes |
Protein-based catalysts that effect specific
biochemical reactions. |
Esters |
Aromatic compounds formed from alcohols by yeast
action. Typically smell fruity. |
Ethanol |
The type of alcohol in beer formed by yeast from malt
sugars. |
Extraction |
The soluble material derived from barley malt and
adjuncts. Not necessarily fermentable. |
Fatty Acid |
Any of numerous saturated or unsaturated aliphatic
monocarboxylic acids, including many that occur in the form of esters or
glycerides, in fats, waxes, and essential oils. |
Fermentation |
The total conversion of malt sugars to beer, defined
here as three parts, adaptation, primary, and secondary. |
Finings |
Ingredients such as isinglass, bentonite, Irish moss,
etc, that act to help the yeast to flocculate and settle out of finished
beer. |
Flocculation |
To cause to group together. In the case of yeast, it is
the clumping and settling of the yeast out of solution. |
Fructose |
Commonly known as fruit sugar, fructose differs from
glucose by have a ketone group rather than an aldehydic carbonyl group
attachment. |
Fusel Alcohol |
A group of higher molecular weight alcohols that
esterify under normal conditions. When present after fermentation,
fusels have sharp solvent-like flavors and are thought to be partly
responsible for hangovers. |
Gelatinization |
The process of rendering starches soluble in water by
heat, or by a combination of heat and enzyme action, is called
gelatinization. |
Germination |
Part of the malting process where the acrospire grows
and begins to erupt from the hull. |
Glucanase |
An enzyme that act on beta glucans, a type of gum found
in the endosperm of unmalted barley, oatmeal, and wheat. |
Glucose |
The most basic unit of sugar. A single sugar molecule. |
Gravity |
Like density, gravity describes the concentration of
malt sugar in the wort. The specific gravity of water is 1.000 at 59F.
Typical beer worts range from 1.035- 1.055 before fermentation (Original
Gravity). |
Grist |
The term for crushed malt before mashing. |
Hardness |
The hardness of water is equal to the concentration of
dissolved calcium and magnesium ions. Usually expressed as ppm of
(CaCO3). |
Hopback |
A vessel that is filled with hops to act as a filter
for removing the break material from the finished wort. |
Hops |
Hop vines are grown in cool climates and brewers make
use of the cone-like flowers. The dried cones are available in pellets,
plugs, or whole. |
Hot Break |
Proteins that coagulate and fall out of solution during
the wort boil. |
Hot Water Extract |
The international unit for the total soluble extract of
a malt, based on specific gravity. HWE is measured as liter*degrees per
kilogram, and is equivalent to points/pound/gallon (PPG) when you apply
metric conversion factors for volume and weight. The combined conversion
factor is 8.3454 X PPG = HWE. |
Hydrolysis |
The process of dissolution or decomposition of a
chemical structure in water by chemical or biochemical means. |
Infusion |
A mashing process where heating is accomplished via
additions of boiling water. |
International Bittering Units (IBU) |
A more precise unit for measuring hops. Equal to the
AAU multiplied by factors for percent utilization, wort volume and wort
gravity. |
Invert Sugar |
A mixture of dextrose and fructose found in fruits or
produced artificially by the inversion of sucrose (e.g. hydrolyzed cane
sugar). |
Irish Moss |
An emulsifying agent, Irish moss promotes break
material formation and precipitation during the boil and upon cooling. |
Isinglass |
The clear swim bladders of a small fish, consisting
mainly of the structural protein collagen, acts to absorb and
precipitate yeast cells, via electrostatic binding. |
Krausen (kroy-zen) |
Used to refer to the foamy head that builds on top of
the beer during fermentation. Also an advanced method of priming. |
Lactose |
A nonfermentable sugar, lactose comes from milk and has
historically been added to Stout, hence Milk Stout. |
Lag Phase |
The period of adaptation and rapid aerobic growth of
yeast upon pitching to the wort. The lag time typically lasts from 2-12
hours. |
Lager |
A beer brewed from a bottom-fermenting yeast and given
a long cool fermentation. |
Lauter |
To strain or separate. Lautering acts to separate the
wort from grain via filtering and sparging. |
Lipid |
Any of various substances that are soluble in nonpolar
organic solvents, and that include fats, waxes, phosphatides,
cerebrosides, and related and derived compounds. Lipids, proteins, and
carbohydrates compose the principal structural components of living
cells. |
Liquefaction |
As alpha amylase breaks up the branched amylopectin
molecules in the mash, the mash becomes less viscous and more fluid;
hence the term liquefaction of the mash and alpha amylase being referred
to as the liquefying enzyme. |
Lupulin Glands |
Small bright yellow nodes at the base of each of the
hop petals, which contain the resins utilized by brewers. |
Maillard Reaction |
A browning reaction caused by external heat wherein a
sugar (glucose) and an amino acid form a complex, and this product has a
role in various subsequent reactions that yield pigments and
melanoidins. |
Maltose |
The preferred food of brewing yeast. Maltose consists
of two glucose molecules joined by a 1-4 carbon bond. |
Maltotriose |
A sugar molecule made of three glucoses joined by 1-4
carbon bonds. |
Mash |
The hot water steeping process that promotes enzymatic
breakdown of the grist into soluble, fermentable sugars. |
Melanoidins |
h2 flavor compounds produced by browning (Maillard)
reactions. |
Methanol |
Also known as wood alcohol, methanol is poisonous and
cannot be produced in any significant quantity by the beer making
process. |
Modification |
An inclusive term for the degree of degradation and
simplification of the endosperm and the carbohydrates, proteins, and
lipids that comprise it. |
Peptidase |
A proteolytic enzyme which breaks up small proteins in
the endosperm to form amino acids. |
pH |
A negative logarithmic scale (1-14) that measures the
degree of acidity or alkalinity of a solution for which a value of 7
represents neutrality. A value of 1 is most acidic, a value of 14 is
most alkaline. |
Phenol, Polyphenol |
A hydroxyl derivative of an aromatic hydrocarbon that
causes medicinal flavors and is involved in staling reactions. |
Pitching |
Term for adding the yeast to the fermenter. |
°Plato, °Brix, or °Balling |
These three nearly identical units are the standard for
the professional brewing industry for describing the amount of available
extract as a weight percentage of cane sugar in solution, as opposed to
specific gravity. Eg. 10 °Plato is equivalent to a specific gravity of
1.040. |
Points per Pound per Gallon (PPG) |
The US homebrewers unit for total soluble extract of a
malt, based on specific gravity. The unit describes the change in
specific gravity (points) per pound of malt, when dissolved in a known
volume of water (gallons). Can also be written as gallon*degrees per
pound. |
ppm |
The abbreviation for parts per million and equivalent
to milligrams per liter (mg/l). Most commonly used to express dissolved
mineral concentrations in water. |
Primary Fermentation |
The initial fermentation activity marked by the
evolution of carbon dioxide and Krausen. Most of the total attenuation
occurs during this phase. |
Priming |
The method of adding a small amount of fermentable
sugar prior to bottling to give the beer carbonation. |
Protease |
A proteolytic enzyme which breaks up large proteins in
the endosperm that would cause haze in the beer. |
Proteolysis |
The degradation of proteins by proteolytic enzymes e.g.
protease and peptidase. |
Racking |
The careful siphoning of the beer away from the trub. |
Saccharification |
The conversion of soluble starches to sugars via
enzymatic action. |
Sanitize |
To reduce microbial contaminants to insignificant
levels. |
Secondary Fermentation |
A period of settling and conditioning of the beer after
primary fermentation and before bottling. |
Sparge |
To sprinkle. To rinse the grainbed during lautering. |
Sterilize |
To eliminate all forms of life, especially
microorganisms, either by chemical or physical means. |
Sterols |
Any of various solid steroid alcohols widely distributed in plant
and animal lipids. |
Sucrose |
This disaccharide consists of a fructose molecule joined with a
glucose molecule. It is most readily available as cane sugar. |
Tannins |
Astringent polyphenol compounds that can cause haze and/or join
with large proteins to precipitate them from solution. Tannins are most
commonly found in the grain husks and hop cone material. |
Trub (trub or troob) |
The sediment at the bottom of the fermenter consisting of hot and
cold break material, hop bits, and dead yeast. |
Wort (wart or wert) |
The malt-sugar solution that is boiled prior to fermentation. |
Zymurgy |
The science of brewing and fermentation. |
