IBD GCD General Certificate in Distilling
- Cereal
Alcohol By Volume (ABV) - answer The standard method of measuring the
concentration of ethyl alcohol (ethanol) in water. The units are percentage (%).
Acetaldehyde - answer An unwanted and highly volatile flavor compound produced as a
co-product (congener) of fermentation and distillation.
Acetic Acid - answer An organic acid (vinegar) also produced as a congener of
fermentation and distilling.
Acetobacter - answer contaminating aerobic bacteria responsible for producing acetic
acid, or vinegar. Has the ability to oxidize lactate and acetate into carbon dioxide and
water.
Aeration - answer The mixing of air with liquid.
Aerobic - answer With the presence of oxygen, which in relation to yeast is needed for
reproductive budding.
Anaerobic - answerWithout the presence of oxygen, which in relation to yeast causes
the yeast to absorb sugars and produce alcohol and CO2.
Alcohol (aka Ethanol, Ethyl Alcohol) - answerThe principal product of fermenting sugar
with yeast (C2H5OH).
Pot Still (aka Alembic in brandy production) - answerVessel, of copper construction,
normally used in pairs (or in two successive operations) for concentration of alcohol
content by batch distillation.
Aleurone Layer - answerA layer of cells under the husk of barley responsible for the
production of enzymes which can break down starch to fermentable sugars.
Alkali - answerOpposite of acid, having pH >7. Strong examples are often used as
sterilising agents because of their anti-microbial effects and within detergents to
dissolve organic soil.
Amyl Alcohol - answerA higher alcohol normally produced in greatest amount during
fermentation, and therefore the principal component of the fusel oil collected during
distillation. Highest concentration is at 65-70% ABV in column still.
,Amino Acids - answerThe individual molecules which make of protein. They are
essential for yeast growth.
Amylase - answerCollective terms for two types (Alpha and Beta) of enzyme which
break down starch molecules to fermentable sugars.
Analyser Column (aka Stripper Column) - answerPrimary continuous-distillation column
for separating ("stripping") alcohol from fermented beer/wash/wine.
Anti-Collapse Valve - answerSafety mechanism on pot stills, mainly to prevent damage
by vacuum developing during discharge of spent contents at the end of distillation, but
some types also relieve pressure above atmospheric.
Aroma - answerCharacteristics of distilled spirit as assessed by the sense of smell, i.e.
by sensory receptors in the nose.
Attenuation - answerA measure of the degree to which wort, molasses or must has
fermented.
Azertrope - answerThe mixture of 97.5% alcohol, 2.5% water which is the highest
alcohol concentration possible in distillation at atmospheric pressure, because of the
attraction forces between the alcohol and water molecules.
Backset - answerRecycled stillage which may be added either to the fermenter or to the
cooker and serves as a source of nutrients. Reduces the amount of water used for
mashing and the amount of liquid residue. Can be a source of bacterial contamination.
Barbet Still - answerType of continuous still in which the analyser/stripping column has
separate pre-stripper and heads concentrator sections; and the rectifier/concentrator
column has a separate section for separation, and venting-off, of undesirable highly-
volatile flavour compounds.
Barley - answerHordeum Polystichum; a cereal used to make malt by process of
controlled germination.
Barrel - answerCask with a capacity of circa 200 litres.
Batch Distillation - answerDistilling of beer or wine in a discontinuous manner - for
example, the pot still is filled, the alcohol and part of the water is distilled off and
collected, the pot still residue is discarded and the whole process can then be done
again.
Wash (aka Beer) - answerTerm used in whisk(e)y distilleries for the product of
fermentation; the fermented extract of malt or cereals.
, Analyser Column (aka Beer Column, Beer Still, Stripper Column) - answerThe primary
continuous-distillation column for separating alcohol from beer/wine/wash.
Blended Scotch - answerLegal definition of a blend of Scotch malt and grain whiskies.
Bonded Warehouse - answerThe building for storage of casks for maturation. Duty
normally is not paid until packaging, a Customs & Excise bond is required to guarantee
eventual payment.
Blending - answerThe process of mixing to produce a homogeneous product which can
be liquid or solid.
Bloom - answerA deposit of micro-organisms, including yeast, found on the skins of
fruit, mostly commonly grapes.
Biological/Biochemical Oxygen Demand (BOD) - answerMeasurement of the strength of
effluent in terms of the amount of the amount of dissolved oxygen (DO) that is used by
aerobic microorganisms when decomposing organic matter in water.
Bonne Chauffe - answerNew-make spirit, usually used to denote brandy.
Botanicals - answerMixture of dried fruits and herbs used for flavouring gin, either by
distillation or by addition as an essence. For both methods, the flavour juniper berries is
an obligatory predominant component of the mixture.
Bourbon Whiskey - answerGrain whisky produced from a cereal mash containing not
less than 51% maize, and distilled in U.S.A. under specified conditions.
Brix (degrees) - answerStandard measurement of sugar concentration (1 degree = 1%
sugar by weight) used for grape must and molasses wort.
Low Wines (aka Brouillis in brandy) - answerProduct of the first stage of whisk(e)y
distillation in pot stills, typical alcohol about 25% by volume. Spirit still charge.
Brown Spirits - answerGeneral term for spirits, principally brandy, rum and whisk(e)y,
which have extracted colour from the cask during maturation.
Butt - answerOak cask, originally containing sherry, with a capacity of circa 500 litres.
Calorie - answerA measure of heat energy.
Carbohydrate - answerAny group of compounds containing carbon, hydrogen and
oxygen. In distilling it is a general term for all sugars and polymers of sugars.
Carbon Dioxide (CO2) - answerThe other main product of fermentation after ethanol,
also a sufficating gas.
- Cereal
Alcohol By Volume (ABV) - answer The standard method of measuring the
concentration of ethyl alcohol (ethanol) in water. The units are percentage (%).
Acetaldehyde - answer An unwanted and highly volatile flavor compound produced as a
co-product (congener) of fermentation and distillation.
Acetic Acid - answer An organic acid (vinegar) also produced as a congener of
fermentation and distilling.
Acetobacter - answer contaminating aerobic bacteria responsible for producing acetic
acid, or vinegar. Has the ability to oxidize lactate and acetate into carbon dioxide and
water.
Aeration - answer The mixing of air with liquid.
Aerobic - answer With the presence of oxygen, which in relation to yeast is needed for
reproductive budding.
Anaerobic - answerWithout the presence of oxygen, which in relation to yeast causes
the yeast to absorb sugars and produce alcohol and CO2.
Alcohol (aka Ethanol, Ethyl Alcohol) - answerThe principal product of fermenting sugar
with yeast (C2H5OH).
Pot Still (aka Alembic in brandy production) - answerVessel, of copper construction,
normally used in pairs (or in two successive operations) for concentration of alcohol
content by batch distillation.
Aleurone Layer - answerA layer of cells under the husk of barley responsible for the
production of enzymes which can break down starch to fermentable sugars.
Alkali - answerOpposite of acid, having pH >7. Strong examples are often used as
sterilising agents because of their anti-microbial effects and within detergents to
dissolve organic soil.
Amyl Alcohol - answerA higher alcohol normally produced in greatest amount during
fermentation, and therefore the principal component of the fusel oil collected during
distillation. Highest concentration is at 65-70% ABV in column still.
,Amino Acids - answerThe individual molecules which make of protein. They are
essential for yeast growth.
Amylase - answerCollective terms for two types (Alpha and Beta) of enzyme which
break down starch molecules to fermentable sugars.
Analyser Column (aka Stripper Column) - answerPrimary continuous-distillation column
for separating ("stripping") alcohol from fermented beer/wash/wine.
Anti-Collapse Valve - answerSafety mechanism on pot stills, mainly to prevent damage
by vacuum developing during discharge of spent contents at the end of distillation, but
some types also relieve pressure above atmospheric.
Aroma - answerCharacteristics of distilled spirit as assessed by the sense of smell, i.e.
by sensory receptors in the nose.
Attenuation - answerA measure of the degree to which wort, molasses or must has
fermented.
Azertrope - answerThe mixture of 97.5% alcohol, 2.5% water which is the highest
alcohol concentration possible in distillation at atmospheric pressure, because of the
attraction forces between the alcohol and water molecules.
Backset - answerRecycled stillage which may be added either to the fermenter or to the
cooker and serves as a source of nutrients. Reduces the amount of water used for
mashing and the amount of liquid residue. Can be a source of bacterial contamination.
Barbet Still - answerType of continuous still in which the analyser/stripping column has
separate pre-stripper and heads concentrator sections; and the rectifier/concentrator
column has a separate section for separation, and venting-off, of undesirable highly-
volatile flavour compounds.
Barley - answerHordeum Polystichum; a cereal used to make malt by process of
controlled germination.
Barrel - answerCask with a capacity of circa 200 litres.
Batch Distillation - answerDistilling of beer or wine in a discontinuous manner - for
example, the pot still is filled, the alcohol and part of the water is distilled off and
collected, the pot still residue is discarded and the whole process can then be done
again.
Wash (aka Beer) - answerTerm used in whisk(e)y distilleries for the product of
fermentation; the fermented extract of malt or cereals.
, Analyser Column (aka Beer Column, Beer Still, Stripper Column) - answerThe primary
continuous-distillation column for separating alcohol from beer/wine/wash.
Blended Scotch - answerLegal definition of a blend of Scotch malt and grain whiskies.
Bonded Warehouse - answerThe building for storage of casks for maturation. Duty
normally is not paid until packaging, a Customs & Excise bond is required to guarantee
eventual payment.
Blending - answerThe process of mixing to produce a homogeneous product which can
be liquid or solid.
Bloom - answerA deposit of micro-organisms, including yeast, found on the skins of
fruit, mostly commonly grapes.
Biological/Biochemical Oxygen Demand (BOD) - answerMeasurement of the strength of
effluent in terms of the amount of the amount of dissolved oxygen (DO) that is used by
aerobic microorganisms when decomposing organic matter in water.
Bonne Chauffe - answerNew-make spirit, usually used to denote brandy.
Botanicals - answerMixture of dried fruits and herbs used for flavouring gin, either by
distillation or by addition as an essence. For both methods, the flavour juniper berries is
an obligatory predominant component of the mixture.
Bourbon Whiskey - answerGrain whisky produced from a cereal mash containing not
less than 51% maize, and distilled in U.S.A. under specified conditions.
Brix (degrees) - answerStandard measurement of sugar concentration (1 degree = 1%
sugar by weight) used for grape must and molasses wort.
Low Wines (aka Brouillis in brandy) - answerProduct of the first stage of whisk(e)y
distillation in pot stills, typical alcohol about 25% by volume. Spirit still charge.
Brown Spirits - answerGeneral term for spirits, principally brandy, rum and whisk(e)y,
which have extracted colour from the cask during maturation.
Butt - answerOak cask, originally containing sherry, with a capacity of circa 500 litres.
Calorie - answerA measure of heat energy.
Carbohydrate - answerAny group of compounds containing carbon, hydrogen and
oxygen. In distilling it is a general term for all sugars and polymers of sugars.
Carbon Dioxide (CO2) - answerThe other main product of fermentation after ethanol,
also a sufficating gas.
