An instrument for measuring a refractive index, which is related to the amount by which the angle of a light wave is changed when passing through the boundary between two media. The amount of refraction is a convenient way to measure solute concentration of a solution and is widely used in viticultural and winemaking to follow the ripeness of grapes and changes during vinification.
The lightest in terms of must weight and alcohol among the trio of dry white wine categories in Austria's Wachau region-specifically for unchaptalaized grapes of 73 to 83° Oechsle which result in wines no more than 11% alcohol. The name comes from a feathery grass species indigenous to the local vineyard terraces.
Very large group of highly reactive chemical compounds of which phenol is the basic building block. These include many natural colour pigments such as the anthocyanins of fruit and dark-skinned grapes, most natural vegetable tannins such as occur in grapes, and many flavour compounds.
The general term used by winemakers to describe the harmless crystalline deposits that separate from wines during fermentation and ageing. The principal component of this deposit is potassium acid tartrate, the potassium salt of tartaric acid, which has therefore given rise to the name.
An accumulation of clay and silt particles that have been deposited by the wind. Loess is typically pale-coloured, unstratified, and loosely cemented by calcium carbonate. Favoured for viticulture because it is porous, permeable, readily warmed and easily penetrated by roots.
An expression for that part of the Bordeaux wine region that is on the left bank of the river Garonne. It includes, travelling down river, Graves, Sauternes, Barsac, Pessac-Léognan, Médoc and all the appellations of the Médoc.
French for "white of whites", may justifiably be used to describe white wines made from pale-skinned grapes. As the great majority of them are. A real significance only when used for white sparkling wines.
Ultratradaitional method of red wine fermentation in which grape berries are not subjected to destemming. This was the default position before the introduction of the crusher-destemmer. The possible disadvantages are that, unless the stems are vey ripe, i.e. well lignified, and the must is handled very gently, the stems may impart harsh tannins to the wine.
Italian term applied to DOC wines which are deemed superior because of their higher minimum alcoholic strength, usually by a half or one per cent, a longer period of ageing before commercial release, or a lower maximum permited yield, or all three.
Winemaking process with the aim of clarification and stabilization of a wine whereby a fining agent, one of a range of special materials, is added to coagulate or adsorb and precipitate quickly the colloids suspended in it.