Good to know: fermentation

Fermentation is the natural process whereby yeast can metabolise sugar to release ethanol as a by-product.

Basically, it’s the stage during the whisky production process when alcohol is made. Fermentation begins when the yeast converts the sugary wort into crude alcohol, producing a liquid similar in aroma and taste to a sour beer called wash. Here’s 5 quick points detailing how fermentation can influence the flavour of the whisky you drink:

• The length of fermentation plays an important part in developing the flavour compounds within the spirit.

• A longer fermentation is thought to produce a sweeter, fruitier wash.

• Benromach has one of the longest fermentations at 115 hours.

• Knockando has a much shorter fermentation at around 50 hours.

• It is quite common now for distilleries to operate partly with a long and partly with a short fermentation.