How Distilling Works: Making Whiskey and Bourbon
There is nothing better than coming home after a long day at work and enjoying a glass of whiskey. It’s feeling the tingle of the whiskey as it brushes your lips, slips past your tongue, and warms your throat all the way to your soul. But how is whiskey actually made? Why is that feeling of whiskey so unique compared to other alcohol? We break down the distillation process and the making of whiskey so you can appreciate your next drink even more.
What is in Whiskey?
Whiskey is a distilled alcoholic beverage made of fermented grains. Different grains are used, including barley, corn, rye, and wheat and all result in a different flavor or kind of whiskey. Whiskeys are also aged in wooden casks, which are sometimes new or sometimes used casks from other alcohol aging.
The history of whiskey spans around the world, with each country having their own signature grains and their own processes. However, most whiskeys follow a similar process.
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Malting
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Mashing
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Fermentation
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Distillation
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Maturation
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Bottling
Malting
Whiskey starts with the raw grain, or a combination of raw grains. Malt whiskeys require the grain, usually barley, to be treated to access the sugars. Malting involves moistening the grain, allowing it to germinate, and then heating the grain to stop the germination process and drying the grain.
The malting process is used for many different whiskeys, especially those made in Ireland and Scotland. American whiskeys typically use more rye and corn, but malt is still a prevalent ingredient in the making of American whiskies.
Mashing
Regardless of the type of grain, or malt, used for the whiskey, the sugar within the grains needs to be extracted. This is done through a process called mashing, where the grains are ground up and mixed with hot water. This creates a porridge-like substance, called mash. Once all of the sugars have been extracted, the mash is ready to move on to fermentation.
What is Fermentation?
Fermentation is where the alcohol begins. The mash is combined with yeast, which eats up all of the sugars in the mash, converting that sugar into alcohol. The process typically takes a few days, depending on the strain of yeast. The fermentation process also introduces different flavors into mash, creating a beer-like liquid with about 10% alcohol by volume.
What is Distillation?
Distillation adds more alcohol into the fermented liquid by heating the liquid into a vapor and then condensing it back into a liquid. Distillation occurs in a still. There are two main types of stills: pot still and column still. Column stills are typically used for bourbon, rye, and other American whiskies.
Column stills are basically a tall column with partitions, or plates, that create chambers within the still. The fermented mash enters at the top of the still as the still is heated from the bottom, making the top of the column the coolest part. As the fermented mash enters it sinks toward the bottom, interacting with hot steam, which vaporizes the mash and forces the alcohol back up the still while the water and grain solids fall back to the bottom of the still.
Each time the vapors hit a plate within the still, they condense again and as they condense and leave heavy stuff (that is not alcohol) behind and keep more of the alcohol. This results in a much higher proof product. Column stills can distill proofs as high as the 190s, or 95% alcohol by volume, however bourbon and other whiskeys are not typically distilled to such high proofs.
Aging Whiskey
Almost all whiskeys are then aged in barrels – usually oak. Bourbon, Rye and some other American whiskeys must be aged in new charred oak barrels, but other varieties of whiskeys can be aged in different types of barrels. To be labeled a straight whiskey, it must be aged in the barrel for at least two years.
American whiskeys and bourbons have additional aging requirements, including specific alcohol by volume.
Bottling
Once ready, the whiskey is bottled, at a minimum of 40% alcohol by volume. The whiskey may also be filtered in some way to prevent it from becoming cloudy when water or ice are added.
