How Is Whiskey Made?

Boilers in the Bruichladdich distillery are pictured Sept. 5, 2006 on Islay Island, Scotland. (Photo by: Harry Melchert/picture-alliance/dpa/AP Images)

“How is whiskey made?”

That seems to be the question on every whiskey drinker’s lips as soon as they discover the deliciously complicated nature of this brown spirit. It would only be natural to wonder about its origin story.

Whiskey is made all over the globe: from Canada and Kentucky to Scotland to Japan and far beyond. Though each country has its own traditions involving whiskey production, the overall process generally remains the same.

Grains of wheat prior to being mashed and distilled. (AP Photo/Matt Slocum)

All whiskey starts with one ingredient: grain. Grain is an important ingredient in the whiskey-making process, and the most common grains used to make whiskey are corn, rye, barley and wheat. A distiller chooses a combination of these grains to make whiskey out of. The amount of each grain used is commonly referred to as a mashbill or grain bill.

If barley is used, it has to be moistened and allowed to sprout during a process called malting. This process allows barley’s natural enzymes to be accessible during fermentation, required to help convert starch to sugar from the grains in the mix. Before the barley can germinate, it is heated and dried.

In order for fermentation to occur, sugars in a whiskey must be readily available. Mashing is a process that helps facilitate this and is when grains in the mashbill are ground up and put into what is called a mash tun — basically a large tank.

The mash tun holds the grain mixture while water is added. This watery, grainy mixture that occurs after the enzymes do their work and convert starches to sugars is all “mashed up,” resulting in what looks like a grainy oatmeal called wort, according to Whisky Advocate.

Some ground malted barley is often added to the wort during mashing, malted barley acts as a catalyst to help the yeasts convert the grains into alcohol during the fermentation process. Some distilleries choose to add liquid enzymes on their own, rather than through the addition of malted barley.

Wort in a mash tank about 24 hours in the fermentation process (Photo: Jay West/Whiskey Raiders)

Fermentation is a key part of the whiskey-making process.

Yeast is the unsung hero of fermentation. During fermentation, yeast is added to the wort. It eats all the sugars in the wort, digests them and excretes alcohol. Though it sounds kind of gross, yeast is the universal hero in the fermentation process of not only whiskey but wine and beer, as well. Fermentation ends when yeast consumes all of the sugar and dies — so sad, we know! Without yeast’s contribution, though, we wouldn’t have alcohol.

Fermentation in the whiskey-making process often occurs in large vessels called washbacks, which look eerily similar to brewing tanks. It makes sense because the distiller is actually fermenting what is commonly called “distiller’s beer,” or a “wash” which has an ABV of around 7%-10% prior to being distilled.

Stills are often made of copper. (Photo: AP Photo/The Casper Star-Tribune, Alan Rogers)

Distillation is what makes whiskey, well, whiskey.

The distillation process occurs when the distiller’s beer is put into a copper still. The purpose of the distillation process is to boil the alcohol vapors so they separate from the liquid then condense them back into liquid again. The distillation process removes unpleasant flavors and aromas, in addition to chemicals.

There are two common types of stills, one of which is a column still and the other is a pot still. Pot stills typically require more work, as pot still-distilled whiskies are made in multiple batches that involve repetition. Column stills, due to their design, work in one continuous — and very efficient — way, where the vapors hit a series of plates until they are directed into a condenser.

Lew Bryson, a whiskey writer, wrote in his book “Whiskey Master Class” that pot stills are often more well-regarded as they require more time and attention to detail, though there are always exceptions to the rule.

“Using a pot still is like cooking a meal from scratch; a column still is like using a microwave,” Bryson wrote

It is worth noting though, that some of the world’s most popular whiskeys are produced on column stills – Buffalo Trace, Jack Daniel’s, and more.

Different types of condensers can be used to capture the vapors, such as worm tubs, which are large vats that collect the distillate.

Oak barrels used to age Jack Daniel’s (Photo by: Kyle Dean Reinford/picture-alliance/dpa/AP Images)

The maturation — or aging — process is what gives whiskey its brown coloring and the majority of its flavors. Prior to barrel aging, whiskey is clear in color when it comes off of the still. Almost all whiskeys are aged in some form of oak barrel.

Different countries have rules as to what kind of vessels can be used, the level of toast and how long a spirit can and must be matured in them.

These oak barrels are typically stored in warehouses, commonly called rickhouses.

Oak barrels are very porous vessels which means oxygen can get into the barrel and a small portion of alcohol can get out. The alcohol that escapes is what is called the “angel’s share.”

Once whiskey is matured to a level deemed satisfactory by whoever is monitoring the barrels, it is bottled at a minimum ABV of 40%.

Some whiskeys undergo a process called chill filtration, which prevents the spirit from being cloudy in appearance. Chill filtering is when the whiskey is cooled to approximately 41-50 degrees Fahrenheit and passed through an absorption filter, as explained by Whisky Advocate.

Though chill filtering makes whiskey look prettier (it won’t get cloudy when poured on the rocks), some critics say it removes some of the fatty acids that create complex aromas in the spirit. Whether a distiller chooses to chill filter or not is entirely up to them, and after that process the spirit is bottled.

A typical bottling run involves multiple barrels in a warehouse, and many distilleries have their own bottling plants.

When one barrel is bottled on its own, it is called a “single cask” or “single barrel.”

After a whiskey is bottled, it enters the wholesale system, where it makes its way to a store and ultimately to your glass of choice.

We’ll drink to that.

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Cynthia Mersten is a writer/editor for Whiskey Raiders and has worked in the Beverage Industry for eight years. She started her career in wine and spirits distribution and sold brands like Four Roses, High West and Compass Box to a variety of bars and restaurants in the city she calls home: Los Angeles. Cynthia is a lover of all things related to wine, spirits and story and holds a BA from UCLA’s School of Theatre, Film and Television. Besides writing, her favorite pastimes are photography and watching movies with her husband.