Scotch Malt Whisky is made from malted barley, water and yeast. The first stage of production is the malting of the barley. The barley is first steeped in tanks of water for 2 to 3 days before being spread out on the floors of the malting house to germinate. To arrest germination, the malted barley is dried in a kiln, identifiable by the distinct pagoda-shaped chimneys, characteristic of every distillery.
Peat, a natural fuel cut from the moors of Scotland, is used to fire kilns in the drying process, along with more modern fuels. Smoke from the fire drifts gently upwards through a wire mesh floor to dry out the barley, and the “peat reek” imparts a distinctive aroma which contributes to the character of the final spirit. When dried, the malt is as crisp as toast.
The malted barley is then ground to a rough-hewn grist and mixed with hot water in a vessel known as a mash tun. This process converts the starch in the barley into a sugary liquid known as wort. The wort is transferred to a fermenting vat, or washback, where yeast is added and the fermentation process converts the sugary wort into crude alcohol, similar in aroma and taste to sour beer. This is known as wash.