CHEMICALS OF WINES                                  [home]  [topic page]

Many chemicals are mentioned in wines as essential to their taste or smell. Many others exist giving the characteristics of the particular wine come from the variety of grape from which they are made..

SUGARS

Grapes, when ripe, have very many chemicals. The sugars that are biochemically created as the grapes ripen are mainly

• D-Glucose ( dextrose, or D(+) - glucopyeranose ) C₆H₁₂O_{6      -}   often called grape sugar.  

 

• Fructose    ( beta-D-frucopyranose )     also C₆H₁₂O₆

It is these that the yeast convert to ethyl alcohol during fermentation.

A high sugar content grape will lead to a higher alcohol level and also a sweeter wine. A wine low in natural sugars is called "dry".

Measurement of the sugar content before fermentation is done with a simple device called a "refractometer" which looks at the refractive index of the juices. The higher the refractive index, the higher the sugar level.

Sugar level is measured in "brix", typically 22 brix is standard for a table wine.

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