Grape Composition and Wine Quality

Grape composition is the essential basis of wine quality, and knowledge of grape composition is critical for those winemakers interested in making the appropriate wine style. The concentrations of all component chemical groups play a part. Grape sugars, for example (see must weight), determine the possible potential alcoholic strength of the wine. acids and nitrogenous compounds (see nitrogen) affect the course of fermentation and exert their own effects on flavour. potassium salts have effects on ph and thus on microbiological activity and oxidative stability. phenolics contribute to levels of colour and tannins. A multitude of volatile compounds alter aroma (see acidity, amino acids, flavour compounds, sugars).