| acetaldehyde |
An oxidation product of ethyl alcohol (q.v.). A fault when sensed
in table wines and beers, but acceptable as an ingredient in the bouquet of sherry or Madeira. It may be
recognised by its sharp, penetrating odour. |
| acetic |
Term used to describe an acetified wine or beer, recognised by a
sharp, vinegary smell and taste. |
| acetification |
A serious disorder in wine or beer, caused by acetic acid bacteria
producing a sour, acrid taint of acetic acid, ethyl acetate and amyl acetate. Exclusion of air is the best
prevention. |
| acid |
A sour-tasting substance, e.g. citric acid as found in lemon
juice. The principal acids found in wine are tartaric, malic and citric, but there are important small
quantities of many others. The word is also used to describe an excess of acidity in wine or beer, as in
"an acid wine". |
| acidity |
The acid taste. The acidity tasted in a wine or beer is
influenced by many constituents of the liquid which can mask or suppress the acid taste. Also the measure
of the acid content of a wine, usually expressed in parts per thousand (ppt), or as a percentage, either
as tartaric or sulphuric acid. |
| adjunct |
An ingredient for brewing, other than malted barley, used to
give colour, flavour, additional extract, or to reduce the chance of protein haze. |
| aerobic fermentation |
Fermentation in the presence of air. Essential in the initial
stages of fermentation in order to promote yeast growth, but must be limited in order to allow efficient
production of alcohol and to prevent spoilage. |
| after-taste |
The total sensation - odour, taste and "mouth-feel"
- remaining in the mouth, throat and back of the nose after a wine or beer has been swallowed. Also known
as the farewell. |
| alcohol |
One of a large group of organic
compounds, each containing the same specific chemical (hydroxyl) group. The
principal alcohol present in wines and beers is ethyl alcohol (q.v.) but
there are others in small quantities which contribute to flavour and bouquet. |
| amber |
Coloured like the substance amber,
i.e. deep yellow to mid-brown. |
| amino acids |
Compounds which are linked together to
form proteins and which are probably important in the flavour and bouquet of
wines and beers. Present in fruits, vegetables and cereals, they are also
released during the degradation of proteins during the mashing of malt. |
| amyl acetate |
An ester formed from amyl alcohol and
acetic acid having the odour known as "pear drops". It is normally
present in very small quantities in wines and beers. An indication of acetification
(q.v.) when present to any considerable extent. |
| anaerobic fermentation |
Fermentation in the absence of free
oxygen, by the exclusion of air. The enzymes from yeast carry out a series of
reactions, changing simple sugars such as glucose and fructose into ethyl
alcohol and carbon dioxide. |
| apple flavour |
A taint in beers made from worts deficient in nutrients and
which is exaggerated by fermentation at too high a temperature. |
| aroma |
Normally that part of the odour of a wine or beer that
originates with the starting ingredients, but often synonymous with bouquet. |
| aromatic |
Describes a fragrant or spicy bouquet or flavour. |
| ascorbic acid |
Vitamin C. Present in fruits, vegetables and honey. Sometimes
used as an antioxidant in wine but, unlike sulphur dioxide, does not prevent bacterial spoilage. |
| astringency |
The tactile sensation (dryness, puckering) in the mouth,
caused by tannins and related substances. Not to be confused with bitterness. |
| attenuation |
The degree to which a beer has
fermented, e.g. highly attenuated beers have low final gravities. |
| autolysis |
In a wine or beer, the breakdown of
yeast cells. The decomposition products may affect the flavour. See "yeasty". |
