A common plant acid, abundant in some fleshy fruits such as lemons, but rare in grapes. The grape is unusual among fruits in that its major acid is tartaric acid, rather than citric acid, whose concentration in the juice of most grape varieties is only about one-twentieth that of tartaric acid.
Downy mildew attacks all green parts of the vine and young leaves are particularly susceptible. When severly affected, leaves will drop off. The loss of leaves reduces photosynthesis and thus causes delays in fruit ripening and, typically, levels of fruit sugars, vine reserves of carbohydrates, and anthocyanins are depressed.
Contrasts with protective and reductive winemaking in that the winemaker deliberately exposes the wine to oxygen at various stages in the winemaking process in order to encourage certain reactions and achieve a particular style of wine. Oloroso Sherry being an extreme example.
French word for the process by which passerillé grapes are dried, shrivelled, or raisined on the vine, concentrating the sugar in grapes-an alternative to wines whose sugars have been concentrated by botrytis.
Also known as Vin du Glacier or Gletscherwein in German, is a local speciality in the Val Anniviers near Sierre in the Valais in Switzerland. The white wine, traditionally made of the now obscure Rèze vine, comes from communally cultivated vines and is stored at high elevations in casks refilled just once a year on a solera system.
Unregulated term of approbation referring to German Rieslings. Use of gold capsules to signify superior quality was a response, initially and still primarily in the Mosel, to the 1971 German Wine Law's prohibition on labels of traditional terms such as Cabinet, feine, feinste, or hochfeinste.
Direct Anglicization of the German Eiswein, sweet wine made from ripe grapes picked when frozen on the vine and pressed so that water crystals remain in the press and the sugar content of the resulting wine is increased. This sort of true ice wine is a speciality of Canada, where it is written Icewine. The word Icewine has been trademarked by VQA Canada which imposes the world's most stringent standards on the production. In Ontario, grapes for Icewine must have reached alt least 35° Brix. Residual sugar at bottling must be at least 125 g/l.
Common winemaking practice, named after its French promulgator Jean-Antoine Chaptal, whereby the final alcoholic strength of a wine is increased by addition of sugar to the grape juice or must, before and/or during fermentation, although if it is added before, the higher sugar level will make it harder for the yeast to multiply.
White winemaking technique wheereby the grapes are not subjacted to destemming and bunches of ripe grapes are pressed whole, with the stems used as conduits for what can often be particularly viscous juice.