a b c d e f g h i l m n o p r s t v w y

haze The persistent cloudiness of a wine or beer due to very small particles in suspension. The colour of the liquid when seen against the light usually differs from its colour when seen by light reflected from it. May be caused by the visible presence of pectins, bacteria, yeasts, starches, proteins or compounds of heavy metals, particularly copper or iron. Best avoided by good practice and use of appropriate enzymes or finings as necessary.
head The froth which appears on the top of a beer after it has been poured. It is formed by bubbles of carbon dioxide gas released from solution, rising to the surface and being prevented from dissipating by a coating of gummy substances in the beer.
head retention The time for the head on a glass of beer to subside and eventually disappear. The presence of detergent or the use of wet or greasy glasses reduces head retention.
hot break Flocculent precipitate of insoluble proteins which forms during the boiling of hopped beer wort.
hydrogen sulphide H2S. The gas with the unpleasant smell of bad eggs. Occurs rarely in wines, and is usually accompanied by related unpleasant-smelling organic compounds of sulphur known as mercaptans. Might be removed by sulphiting and racking or aerating. If this fails, try brief exposure of the wine to bright copper metal.

Last updated: 04/01/10
Copyright: 2006 NGWBJ