For a recipe that has only three ingredients (barley, water, and yeast) and four main steps (malting, brewing, distillation, and maturation), it’s remarkable how much variation the end product can have. And for a process that is incredibly scientific, its ultimate success is more due to artistry than any sort of technical prowess.
Yes, folks, it’s time to learn how whisky is made. At least, it is time to learn the common steps involved in the process. Unfortunately, the specific secrets of each distillery and of each master distiller remain theirs and theirs alone.
The whisky-making process starts with a little something called malting. Kinda an important step, when your product is malt whisky, single or otherwise.
In short… malting is the method by which the starch contained in each grain of barley is converted into soluble sugars, necessary for producing alcohol at a later step.
Barley grains are first soaked in water for about two or three days. As the barley absorbs the water and its moisture content increases, germination starts. In the dim recesses of your mind, you may recall doing something similar to this at school when you first learned about germination in science class… I remember placing a seed-of-sorts between two pieces of soaked cotton wool, and having to keep these wet at all costs so that my some-kind-of-seed would start germinating and I wouldn’t have to admit to my teacher that I was a cereal killer.
Once the germination process has begun, the barley is spread over the malting floor in a layer about 20 to 30 cm thick. As each barley grain germinates, it gives off heat – negligible if the barley has the luxury of room to breathe, but potentially dangerous when there are many barley grains all doing their darndest to grow in one small space. We all know that heat and overcrowding leads to accidents happening. One minute everything’s okay. The next – everyone’s killing everyone else and committing suicide in remorse. To prevent this unfortunate state of events from occurring, the germinating barley is turned several times a day to maintain an even temperature of about 16°C. In a traditional maltings, this turning is done by hand using wooden shovels called shiels.
The point of all this effort is that germination causes the barley to secrete an enzyme called diastase. It is this that results in the starch in the barley converting into sugar.
Once this conversion has happened, and before the barley can consume the sugar for further growth, the germination process is stopped. Unsurprisingly, yelling “stop” at this point doesn’t work. Instead, the barley is placed into a kiln for one or two days to remove excess moisture in the barley grains. No more water, no more growth.
It is at this time that distilleries can start to introduce a “peat reek” to their whisky if they so desire, by using peat as fuel to fire the kiln. For less peaty whiskies, coal or oil is used as fuel, or (in the case of Irish whiskey) the kiln is completely closed so that no smoke comes into contact with the barley.
The pagoda roof on a distillery will show you where its kiln is or used to be. This style of roof was introduced in the late 1800s as it was specially designed to provide an improved air draught, drawing the smoke upwards quickly to prevent heat damage to the barley.
Unfortunately, the pagoda roof on many (if not most) distilleries these days is purely for show. Apart from a handful of distilleries, the malting process is carried out off-site at an industrial maltings, where the entire process is automated.
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