What’s the Difference Between Brewing and Distilling? Ask Paul

Brewing is the process of fermenting grain, fruit, or other ingredients to make alcoholic beverages including beer, wine, hard cider, and sake. Distilling is the process of taking an alcoholic brew and concentrating it to make whiskey, vodka, gin, or any other hard liquor.

Although we also use the word “brewing” in reference to coffee and tea, today we’re here to talk about alcohol. Brewing in this context means encouraging grain, fruit, or other ingredients to ferment into an alcoholic drink. The majority of work here is done by yeast, the helpful fungus that converts sugar into alcohol and carbon dioxide. The same species of yeast, Saccharomyces cerevisiae, is used for both brewing and baking, and many thousands of strains of that species exist, specialized for various tasks. 

Some starting ingredients, such as grapes and other ripe fruit, are already full of sugar and ready for the yeast to go to work. 

Many others, though, such as the grains used to make beer or whiskey, are predominantly starch. For those, the brewer needs to jump-start the process by breaking down starch into the sugar that yeast eat. That’s commonly done by cooking grains (called “mashing”) with enzymes known as amylases, which in the case of whiskey are typically provided by malted barley. Once the grain has been mashed and it’s full of fermentable sugars, it’s called “wort.”

Now the yeast can do their job, over the course of several days (I’m looking at you, Russell). As the fruit, wort, or other sugar source sits, yeast ferment the sweet liquid into an alcoholic, and sometimes bubbly, one. As the alcohol content rises, it kills the yeast. Once the brew reaches about 10 to 15 percent alcohol, the yeast die off and fermentation stops.

Take the brewing process to this point and you’ve made beer, if you started with grain. Or, if you started with grapes, you’ve made wine. If your aim is a deliciously drinkable beer or wine, additional steps—aging, filtering, hopping—are required. But if you want to make hard liquor, which typically comes in at at least 40 percent alcohol, distilling is necessary.

Distilling is a physical rather than a biological process, which means it’s generally simpler than brewing. However, it’s also illegal without a license in the United States, which is why home brewing of beer is a popular hobby and home distillation of spirits is typically done in secret. Laws vary, though—home distillation without a license is perfectly legal in New Zealand, whereas home brewing is illegal in Japan.

Distilling starts with the brew created by brewing (see above). The brew created by yeast fermentation primarily consists of water and alcohol. Thanks to the miracle of physics, these two liquids boil at different temperatures: water at 212 degrees Fahrenheit, and alcohol at 173. What that means is that, when the mixture heats up, the alcohol starts to evaporate first, and the water afterward.

A still is a device designed to take advantage of that fact. In the simplest terms, it heats up the brew, captures the alcoholic vapor as it evaporates, and condenses it back into liquid, drop by drop. That process deftly separates the components according to their boiling points, which works out to the same thing as separating them according to their alcohol levels.

As the distillate comes out of the still, it starts off highly alcoholic and gradually becomes less alcohol and more water.

By selecting only some of the still’s output, a distiller can concentrate the alcohol to create as potent a spirit as desired. This clear spirit is frequently aged as a next step, to mellow the flavor and, if the aging is done in wooden barrels rather than stainless vats—as in the case of whiskey, brandy, and rum—to impart some color and flavor from charred wood.