White wine the death knell of northern viticulture. The vine disappeared from northern Germany and Baden, and the maximum altitude for viticulture descended to 220 metres. Hans-Jürgen Otto noted that: "all the vineyards suffered and decreased in area". In England the vine also disappeared. The less early vineyards preferred to select white varieties of grapes because, even if unripe, white grapes allowed wine that was a little sour to still be consumable, while red grapes do not give enough colour and green tannins make the wine bitter. The interruption of the fermentation by a cold winter led to the discovery of the
Wine Grapes franc may have originated in Basque country of Spain. Additionally the origins of the assumed to be French varieties of Mourvèdre, Grenache and Carignan are shown to likely be Spanish instead. Another detail revealed by DNA testing and reported in "Wine Grapes" is that several northern Italian white wine grape varieties including Favorita, Pigato and Vermentino are genetically the same grape vine which is known under the synonym of "Rolle" in France but has no genetic relationship to the Rollo grape of Liguria. A number of grape varieties are illustrated by reproductions of colour plates from "Ampélographie. Traité général de