Grape skins as supplements for color development in Pinot noir wine

Abstract

A particular challenge to making wine from Pinot noir grapes is the delicate flavor, light color and poor ageing potential of the wine. Conventional Pinot noir must preparations were compared with those made using a skin-based supplement to assess the impact on non-bleachable (sulfur resistant) pigments in the wine. When supplemented with either fresh grape pomace of Pinot noir, Pinot gris or Chardonnay grapes; Pinot noir grape marc or a commercial liquid grape skin extract, the additional seeds and pulp from the supplements were shown to compromise the development of stable pigments in the wine. To compare the relative merits of tannin derived from grape skins and seeds, the supplements used in a parallel experiment were the skins alone of the same three grape varieties and at six months bottle age, the stable pigment concentration was found to exceed the amount attributable to the supplement. A third experiment used fermented grape skins as the supplement, with 85% of the supplementary anthocyanin recovered as stable pigment complexes in the wine. Notably, this series of experiments showed that supplements containing grape seeds appeared to compromise non-bleachable pigment formation in the wine while skin only supplements stimulated their development.

Keywords: Anthocyanin; Diammonium phosphate (CID: 24540); Ethanol (CID: 702); Grape marc; Methanol (CID: 887); Methyl cellulose (CID: 2724070); Non-bleachable pigment; Phloroglucinol (CID: 359); Potassium hydrogen tartrate (CID: 23681127); Potassium metabisulfite (CID: 28019); Seed; Skin; Sodium hydroxide (CID: 14798); Sodium metabisulfite (CID: 656671); Tannin; Tartaric acid (CID: 875).