What is whisky? A simple question with a complex answer. The nature of whisky can be interpreted several ways. Does one want to know how whisky is made? There are several answers to that question. Does one want to know the components used in whisky production? What it’s made of? How it tastes? Again, multitude of answers.
In this post, I will briefly explain single malt production.
All Scotch is made from malted barley. Malt is dried germinated cereal grain. The grain is soaked in water to germinate and then dried by hot air to stop the germination process. This allows it to produce sugars.
Some manufacturers will use peat to dry the malt, giving the flavour to the barley.
The malt is then ground and mixed with hot water in what is called a tun. Starch turns to sugar at this point. The sweet liquid, called wort, is drained until all the sugar is gone. The speed with which the wort is pushed through the tun affects flavour. The quicker the wort is sent through the tun, the more cereal, nutty, and dry the final product.
The wort is cooled and sent for fermenting in a contained called a washback. The washback is made of wood or stainless steel. Yeast is now added.
The wash is then distilled in copper pot stills. There are different kinds of stills that lend different characteristics to the wash depending on the length of time the alcohol vapour is in contact with the copper. Long stills extend this contact, resulting in generally lighter spirits. The opposite effect occurs with shorter stills.
The vapour is then liquified using cold water through a condensation system. The vapour hits the cold pipes and turns back into liquid form. Again, the copper exposure plays a role in whether the final product will be light or heavy.
The spirit must then be cut. And early versus late cut will affect the flavour as well. Early cuts will tend to be more fragrant, a later cut will result in a more heavy product.
The spirit is now ready for maturation. The alcohol content is reduced to just about 60% alcohol by volume and placed in oak casks. Often, these casks have been used before for bourbon or sherry.
A bourbon cask is made from American oak. Sherry casks are made from European oak. Refill caks have been used by the distillery before. Usually a distiller will use all three to distinguish their own brands and develop flavours.
The whisky may then be aged a second time for a short period in another cask that may have been used for wine, port, sherry, etc. to give further complexity to the final product.
The whisky aging process is the time it takes for the wood to add its own characteristic to the whisky. A new cask will give off more flavour than one that was previously used.
The whisky bottling process is also important in the final product taste. Chill filtration involves cooling the whisky to -10 C to 4 C and passing it through a filter. Non-chill filtration may be used, but it may resulting in a cloudy product, especially when water is added. Some distillers (and whisky lovers) feel non-chill filtration removes less flavour from the product and prefer to use this method instead.
The minimum strength is 40% for whisky.
So that’s the single malt process in a nutshell. You could get much more detailed information on this from Wikipedia or some excellent books on the subject. There are more and more these days as whisky’s popularity explodes. In my opinion, a more complex, refined drink than wine that runs none of the risks.