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What Alcohols Can Be Found In Wine.

• Next to water, alcohol, by volume, is the next major wine component, with ethanol being the main alcohol.
  
  
• Glycerol is a poly, tri-alcohol, and can also be found in wine. But unless the grapes were heavily affected by botrytis, will only be present in small quantities.
  
  
• Methanol, methyl alcohol or wood alcohol can be produced by yeast during fermentation at levels of 0.1g/L (0.01 %v/v).
  
  Most of the methanol in wine is derived from grape pectins with the highest levels found in red wines because of the extended maceration on skins.
  
  It is the alcohol well known for causing blindness or even death when concentrated to toxic levels, through distillation.
  
  However, the main source of methanol poisoning is adulteration .
  
  
• Other alcohols are also produced by yeasts in minor quantities, however can have important flavour implications.
  
  These are the-
  
  
  Polyols (poly-alcohols - alcohols with more than one hydroxyl group - see diagram)-
  
  
  • Glycerol (mentioned above)
    
    
  • Butylene glycol or 2:3 butandiol (0.3 - 1.5 g/L), another poly-alcohol like glycerol, with a sweet flavour tending to bitterness at high concetrations
    
    
  • Inositol (0.5g/L ) a cyclic, poly-alcohol found in grapes and metabolised from fructose
    
    
  • Sorbitol 0.1 g/L
    
    
  Higher alcohols (alcohols with more then two carbon atoms per molecule or fusel oil)