Whisky, the amber liquid, the elixir of life, aqua vitae – the water of life or originally the Gaelic uisge beatha. Whatever your take on this wonderful spirit, it holds a fascination for drinkers world wide because of its complex aroma and taste. It compliments many different foods and is suitable for every mood and occasion. It may arouse the appetite before a meal, compliment the food during dinner and even soothe digestion after eating. It makes the perfect drink in the evening with canapés, nuts and olives, whilst being the ideal nightcap after a busy day.
Whisky is available in many different guises from the most commonly sold blended whiskies to single malts, blended or vatted malts as well as grain whiskies and American bourbon. It also comes in different strengths – commonly 40 or 43% proof and recently 46%. There are also the cask strength varieties which are typically 57-59% proof. Today the fasted growing part of the market are the single malts. Their popularity has no doubt grown because of the variety – something to please every whisky drinker – and their engaging aroma, taste, consistency and aftertaste. Thus this column will concentrate mainly on the single malts…
All single malt whisky is produced from the same three ingredients, viz. water, malted barley and yeast. It is the the character of the water, the environment and the process which define each different expression.
Firstly pure, clear water is needed for excellent whisky distillation. The water in Scotland cascades down the hills, filters through granite mountainsides, passes through thick peat bogs or rises from springs in the ground. The journey across the fields and the natural vegetation impacts on its unique character and ultimately the personality of the final dram. The process begins by soaking the barley in water for about two days allowing the barley to germinate and begin to produce its starches. The wet barley is then spread over the malting floor for about a week where it is regularly turned and agitated with wooden shovels. Once the required amount of germination has occurred, the barley is stopped from growing by drying. Natural products to fuel the fires in Scottish distilleries are commonly coal, heather or peat which are all available locally in abundance. The distilleries using peat impart a smokey aroma and taste of phenols to their malts.
The dried barley is now ground to a fine grist in a process called mashing. This is placed in large mash tuns where boiling water is added. The boiling water dissolves the flour releasing the sugars resulting in a liquid known as wort which is drained off and passed into fermentation vessels called washbacks. The solids, called draff in Scotland, are used for cattle feed. Now the yeast is added and rotating blades in the washbacks keep the liquid agitated as the sugars are fermented into alcohol. This process is similar to producing beer and the resultant liquid contains approximately 7-8% alcohol.
Now the fermented wort is piped to the copper stills which are unique in shape and size for each distillery. There is typically two distillations which occur and it is the middle fraction of the second distillation which is collected for maturation. This liquid is much like clear surgical spirits and is typically approximately 70% alcohol. Using the same water, the alcohol is diluted to 63% which is ideal for maturation in oak casks for a minimum of three years for it to be legally called Scotch whisky. Only second hand casks are used in Scottish whisky, as opposed to bourbon which is matured only in new casks. Here the liquid absorbs the character of the wood and the previous contents of the barrel and
becomes softer, smoother and achieves its amber colour. Typically the barrel is left undisturbed for between ten and eighteen years before the stillman elects to bottle the single malt. Finally, before bottling, the whisky is chilled and passed through a bed of filters to remove impurities and esters which cause cloudiness when water is added. The whisky is then bottled and will not change after this point. It can be opened and will remain true to its character for approximately five years. I hope it never lasts that long!
(for more whiskey delights see our specialist Maish Weinstein’s Whiskey blog)