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 a lasting influence on the science of French winemaking. Pasteur was asked to help identify wine quality control issues that caused spoilage and other faults. During the 3 to 4 years that Pasteur spent studying wine he observed and explained the process of fermentation—noted that it was living organisms (yeast) that convert sugar in the grape must into alcohol in some form of chemical reaction. He also noted the presence of glycerol and succinic acid in wine as well as the beneficial process of adding tartaric acid during winemaking. Another observation that Pasteur made was that oxygen played a significant