The production of the whiskey is comparatively easy. The barley is allowed to germinate until the starch of the grain has turned into malt sugar. The malt is then kilned and coarsely ground. The sugar is leached with hot water, and the liquid is prepared to ferment. The result is a beer without the addition of hops. This beer is then distilled twice on copper stills, the pot stills. It comes in barrels made of oak wood for maturation before it goes for at least three years in the bottle. High-quality single malt whiskeys sometimes mature for decades.
Malting the barley
When the barley has a water content of 45% after soaking, starch to sugar works best. The barley must be turned by hand at precisely defined intervals so that all the grains germinate evenly. The process of germination takes about 5 days.
The malt pulp in the Mash Tun is leached with water three times before the sugar solution is cooled down in a cooler. The first time you use hot water with a temperature of around 65 ° C. The second time the temperature is already 80 ° C. The last time the temperature is increased to just under the boiling point (95 ° C). The third and final time, the sugar is so little dissolved that you let the weak sugar solution cool down a little and use it for the first run of the next batch. The water is extracted from the leached mash in separate factories, and the remainder is processed into animal feed. You can smell the exhaust air from these factories for miles.
The alcoholic fermentation
The washbacks are provided with lids so that no vinegar bacteria penetrate and the fermentation foam does not overflow. In addition, the washbacks have a large, horizontally running propeller at the top, which repeatedly knocks the foam down. The fermentation vats are usually made of Oregon Pine or Cypress, as these woods are particularly resistant to fungi. More recently, stainless steel has also been used as a material, as it does not have to be impregnated or cleaned so much with chemical agents.
The wash is poured into the first copper still, the pot, and heated from below or inside. The heating is mainly done indirectly with superheated steam, more rarely with an external gas flame. In the first case, highly heated steam is passed through specially shaped heating pipes inside the pot still. This heats the surrounding wash. From a temperature of 78 ° C, the alcohol begins to boil before the water. The alcohol vapor rises the tapered tube.
The wash stills usually hold between 20,000 and 30,000 liters, whereas the spirit stills only hold 10,000 to 20,000 liters of the more concentrated low wines.
It is even said that dents and dents are carried over from the stills to the renewed stills. But this belongs in the fairytale hour.
The first distillate from the pot still could theoretically contain the volatile and poisonous methyl alcohol (methanol), which, if consumed in abundance, leads to blindness and even death. However, today’s modern yeasts were all bred so that they no longer produce methyl alcohol. The separation of the forerun, therefore, only has a taste character. The caster from the pot still contains the fusel oils that are responsible for the headache. Since the after-run of single malt whiskeys is stopped quite early, almost no people tend to have headaches after consuming single malt whiskey.
The bottling in barrels
According to the law, every barrel must be marked with a unique number, the distillery’s name, and the year of distillation. In the past, this was done with a stencil, along with paint and a brush. For some years now, distilleries have been increasingly using barcode labels that only a computer can read.
With the filling of the water-clear and colorless raw whiskey in barrels, the single malt whiskey production is completed. It is then matured in barrel storage.
The maturation in the barrel
The origin of the drums is for later whiskey – taste crucial. Most distilleries store their whiskeys mainly in American bourbon barrels. These barrels were made from American white oak and have already been used once to store bourbon whiskey. Many distilleries such as The Macallan or Bowmore, on the other hand, rely on barrels in which Spanish sherry was previously matured or another wine. The barrels must always be made of oak exist. A malt from Springbank, stored in rum barrels from the Caribbean and took on a greenish color, is legendary.
Barrels are regularly refurbished in the barrel makers so that some barrels are used several times and over decades. Naturally, the whiskey from a sherry cask used for the second time to store whiskey will absorb less sherry flavor than in a fresh one. Due to these many different influences, an individual whiskey is created in each barrel over time.