Ethanol and carbon dioxide are the main products of wine fermentation. In this process many other chemicals compounds, described as by-products, are produced. The third quantitatively product of fermentation is glycerol. The next components are: aldehydes, esters, organic acids and other alcohols, including higher alcohols. These compounds influence the quality of finished wine product. The amount of these compounds depens on yeast strain, must composition and different fermentation conditions.