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
Wine average ones. Some vintage wines (e.g. Brunello), are only made in better-than-average years. For consistency, non-vintage wines can be blended from more than one vintage, which helps wine-makers sustain a reliable market image and maintain sales even in bad years. One recent study suggests that for the average wine drinker, the vintage year may not be as significant for perceived quality as had been thought, although wine connoisseurs continue to place great importance on it. Wine tasting is the sensory examination and evaluation of wine. Wines contain many chemical compounds similar or identical to those in fruits, vegetables, and spices.