3.10 describe the manufacture of ethanol by the fermentation of sugars, for example glucose, at a temperature of about 30°C

Production of Ethanol

Ethanol can be produced in two ways - fermentation or direct hydration of ethene.

Fermentation:

1. Dissolve sugar or starch in water and add yeast
2. Leave the mixture to ferment at 25-40°C for several days - anaerobically
3. Filter off the excess yeast to obtain a dilute solution of ethanol

When the ethanol content reaches around 15% then the yeast is killed.

If you need a more concentrated solution then this must be fractionally distilled.

NB - the enzymes in the sugar produce glucose and then convert it into ethanol.

Sugar / Starch à C₆H₁₂O₆

C₆H₁₂O_{6 ­}à 2C₂O₅OH + 2CO₂