We all want answers to the big questions in life. What happens when we die? What is love? What exactly is Mr. Blobby supposed to be, and who decided that it was acceptable to allow that festering nightmare to be on children’s TV? 

In whisky circles, the big questions are often the simple ones. Whisky nerds like us love to get geeky about the minutiae of fermentation, but when we’re spreading the good word about whisky we need a concise, comprehensive answer to the questions people just getting into whisky will ask. What is Scotch? What is Scotch made from? The latter is the exact question we will tackle today. 

What is whisky made from?

To make whisky, you need grains. That’s true of all whisky, not just Scotch. Barley, wheat, corn (maize), and rye tend to be most commonly used, but you sometimes see varieties like millet or oats used. 

Bruichladdich's Bere Barley

Barley is the grain most associated with Scotch whisky, but it’s not the only one used

What grain is Scotch whisky made from?

At the heart of most Scotch whiskies is malted barley. Barley is a cereal grain that needs to be malted, a process of germination that entails soaking the grain in water, to activate enzymes that convert starches present in the barley into fermentable sugars. After a few days, the germinated barley, often called ‘green malt,’ is dried in a kiln. This halts the germination process and gives you malted barley. The malted barley is then ground down into a coarse flour called grist, which is ready for the next stages.

To create malt whisky, you can only use malted barley. That’s it. 

Grain whisky, on the other hand, is made from a mixture of grains, which can include barley, corn, wheat, and rye. So grain whisky can contain malted barley, but it’s not the sole ingredient. Corn is the most common and gives the spirit a sweet, smooth character. 

Scotch whisky is defined by several categories that are rooted in the type of grain used. There’s single malt, made from 100% malted barley and produced at a single distillery, and single grain, produced at a single distillery but can be made from other grains in addition to malted barley. Then there’s blended Scotch whisky, a marriage of one or more single malt Scotch whiskies with one or more single grain Scotch whiskies. Finally, blended malt, a blend of two or more single malt Scotch whiskies from different distilleries, and blended grain, a blend of two or more single grain Scotch whiskies from different distilleries.

Water and yeast

To make whisky you also need water. It’s used in various stages of the whisky-making process, from mashing and fermentation to dilution before bottling. There’s some debate over the extent to which the purity and mineral content of the water influence the character of the whisky. Certainly, many distilleries in Scotland pride themselves on using natural water sources, often from springs or streams, believing it contributes to the unique character of the whisky.

Yeast too plays a pivotal role. You can’t make alcohol without fermentation. If you were making whisky from malted barley, for example, you would need to mix it with hot water in a mash tun to create ‘wort,’ a sticky and sweet liquid that is the result of the glucose in the grain being activated. 

The wort is transferred to washbacks (large fermentation vessels) where yeast is added, which consumes the sugars from the wort and produces alcohol and carbon dioxide. This transforms the sugary wort into a liquid called ‘wash,’ which is essentially a type of beer. Not one you’d want to drink, however, but one you would want to distill. 

What is peat?

Peat: nature’s greatest flavour brick.

Peat, oak, and time

In some Scotch whisky production, peat is used to dry the barley and halt the fermentation process. Peat is essentially a type of soil that’s rich in organic material that’s found all over Scotland and when burned, it gives the barley a distinctive smoky aroma that carries through fermentation, distillation, and maturation. There’s more info on the power of peat in this dedicated guide on the matter that we highly recommend. You wouldn’t exactly define peat as an ingredient used to make whisky in the same way you would grain, water, and yeast, but it plays an important role nonetheless.

The same can be said for wood, and if you’re the romantic sort, time. After all, a spirit cannot be called Scotch whisky unless it is matured in oak casks for at least three years, though many are aged much longer. The interaction between the spirit and the wood of the cask over time imparts colour, flavour, and complexity to the whisky.