Tannins play three distinctive roles in making wine. The first is flavor; tannins increase the zesty flavors that are often left lacking in many homebrewed wines. The literal definition of tannin is the " zest " or peel of the grape. Tannins aid in the clarification process by neutralizing residual proteins and other proteins, these drop out of suspension by the simple presence of tannins. Tannins also aid in the aging and keeping qualities of wines; wines that are deficient do not take advantage of the aging process very well. Their improvement with time is only marginal and these wines also tend to deteriorate in quality more rapidly in longer storage situations.