Whisky basics

Did you know?

The make up of peat is different in different parts of scotland and thereby influences the flavour of the whisky.
An example
There are very few trees on the Orkney islands so there are no tree roots in the peat making it lighter and quicker to burn. Whiskies from this area, like Highland Park, tend to have a lighter smoky flavour than Islay malts

example whisky banner

Influence of peat

Peat is found all over the british isles and it is the use of peat in the scottish whisky industry that helps to produce a drink that has a unique flavour within the world of spirits. Peat is earth that consists of grasses, moss and soil that has become tightly compacted over thousands of years.

Use in the whisky industry
The peat is cut (normally by hand) and then left to dry in the open air for approximately two weeks. After this time, the peat is collected and then taken to the distillery. Most of the time the peat used is local to the distillery or cut from property owned by the distillery. The peat is burnt underneath the malted barley to stop its germination (see How is whisky made for further explanation). Peat is so tightly compacted and dense, it burns for a long time and with consistent heat and smoke. This is also why it is still widely used as a domestic fuel in some areas of Scotland.

Different characteristics
Peat is one reason why different distilleries have different characteristics in their whiskies. Peat smoke produces contains chemicals called phenols and these phenols are absorbed by the malted barley during this process. The level of phenols are controlled by the length of time that the barley is exposed to the smoke, the amount of smoke produced and the type of peat used.

Phenols
Once finished, the malt is taken away for mashing and the phenol level is measured. This level is known as the ppm – parts per million. A distillery will always have the same ppm for their malt and this value is also measured in the final spirit. Some is lost during distillation so the ppm is always lower at the end, roughly one third of the level of the original ppm. The ppm figure most commonly used is that of the malt. All whisky has some smokiness but in most the ppm value is so low (eg. 1–5 ppm) that it is virtually undetectable. In smokier whiskies, it is easier to detect these levels as the ppm increases.

ppm values
Here are some examples of ppm values of some distilleries
(the approximate ppm of the malt is in brackets in increasing value)