Whisky is one of the most popular types of distilled alcoholic drinks, made from fermented grains. The preferred grain type varies from region to region, ranging from barley (very popular in Scotland), malted barley, rye, wheat, and corn (which is the main ingredient of American Bourbon). An exception is Indian whisky, which is traditionally made not from fermented grains, but from fermented syrup.
The existence of whisky can be traced back to the ancient times, almost to 2000 BC in the kingdoms of ancient Babylon and Mesopotamia. However, the modern history of whisky began between the 11th and 13th centuries when Christian monks brought the art of distilling to the Northern England areas of Scotland. It was during this time that the art of distilling began to progress, and the regions of Scotland (well suited to produce grain products) became the world’s most popular producers of whisky.
The basic process of whisky production has not changed over the past 200 years. Technological advances allowed brewers to control every aspect of this process, but the fundamentals (use of water, barley and yeast) and local laws meant that the original recipes that gave the original popularity to this fascinating drink were preserved.
The basic processes in making whisky:
The main component of barley responsible for creating alcohol is starch. To take full advantage of this effect, the barley must sprout, often called “malting”. When the brewery has chosen the grain it wants to use, it soaks it in water and spreads it on the floor of the so-called “malting house”. After several days of resting (grain has to be turned regularly to maintain a constant temperature), the malting process is stopped by rapid drying in an oven (Scottish barley is often dried with peat smoke, which gives the final product specific aromas). After the dried malt has been ground in a mill, all the dirt is removed, or “the wheat is separated from the chaff”.
The extraction of the sugar from the grain is done by adding hot water, which allows the sugars to sink to the bottom of the still. The quality and type of the water is important for the end product – natural spring water usually contains a wide variety of minerals. Adding hot water is repeated twice, but the removal of the sugary water from the bottom of the barrel is only done the first two times. The yield from the final removal is not used for whisky production but is used as animal feed.
The fermentation process in whisky making is done in tanks called washbacks. After adding the carefully selected yeast, fermentation begins, and the sugar slowly turns into alcohol. After about two days, fermentation stops, and the liquid will have an alcohol content of only 5-15%.
The distillation process is used to increase the alcohol percentage to 90% and remove unwanted substances (such as methanol) from the mixture. The majority of Scotch whisky is distilled twice, Irish whiskey three times, but some recipes require up to 20 distillations. The process itself is done in traditional Scottish pot stills (best suited for single malts), Coffey stills (which are better suited for grain whisky) or industrial “continuous” distilleries. In any case, the fermented liquid is heated to boiling point (lower than that of the pure water), which causes the alcohol to evaporate and the steam is collected in the condenser. The liquid produced has an alcohol content of 20% and must be reprocessed. After the second distillation, the liquid can reach the maximum allowed percentage of 94.8% alcohol enforced by Scottish and many other countries’ laws.
Before the whisky is matured in oak barrels, many recipes require dilution of the whisky to about 63 to 64% alcohol content. After maturing in barrels for several years (varying in time in different countries – America two years, Scotland and Ireland three years), whisky absorbs different components of the wood, changing the taste and colour. Many of the well-known whisky brands have a very long maturation process, ranging from 3 to 4 times longer than required by law.
Bottling and final whisky making processes
Before whisky is bottled, a few final processes are required. Filtration is done to remove any unwanted acid esters that become visible in the bottle after prolonged exposure to a cold environment. Finally, the colouring of the whisky is done by adding strict amounts of caramel.
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