Wine color practice of saignée (exposing wine to red grape skins for only a short period of time in order to give it a lighter feel closer to that of white wine) or by blending a white wine with a red wine. The presence of a complex mixture of anthocyanins and procyanidins can increase the stability of color in wine. As it ages, the wine undergoes chemical autoxidation reactions involving acetaldehyde of its pigments molecules. The newly formed molecules are more stable to the effect of pH or sulfite bleaching. The new compounds include pyranoanthocyanins like vitisins (A and B), pinotins and
History of French wine role in the aging and improvement of wine. Pasteur identified several causes of wine spoilage including some that could be controlled during winemaking. He noted that "graisse" was due to the production of polysaccharide, degradation of sugars led to mannitic acid and that the degradation of glycerol led to bitterness in the wine. Pasteur found that the particular problem of Burgundy wine spoiling and turning into vinegar on long voyages to England was caused by the bacterium acetobacter. The results of Pasteur's studies revolutionized the French understanding of winemaking and eventually spread to other wine regions across the globe. The