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 fraud stable isotope analysis and isoscapes are likely to grow in importance. Some practices of manipulation and adulteration have gone through stages of being considered fraudulent and later accepted as common practice. One of these is the practice of blending other grape varieties in order to add a characteristic that is lacking in the original wine. This most often occurred in the case of a wine lacking color. A wine with a deep dark color is often associated with being of a higher quality, so blending a darker color variety (or a teinturier) into a lighter wine could enhance the marketability