You’d think that all spirits, whether gin, rum or whiskey, are basically made the same way, right? Not exactly. Although it’s true that each of these styles of alcohol undergoes similar processes, the details behind every bottle are a bit different.
So how are spirits produced? In short, via distillation. Distillation is what sets spirits apart from beer, wine and other styles of nondistilled alcohol. Alcoholic beverages can basically be broken down into two categories: fermented (or nondistilled) beverages and fermented (distilled) beverages. Fermented beverages that do not undergo a distillation process include beer, hard cider, mead, saké and wine. Alcohol that’s fermented and distilled includes brandy, gin, rum, vodka and whiskey. In this explainer, we’re focusing on this latter category—the general aspects, that is. A given category may require additional steps that aren’t covered here.
1. Preparing the Mash
In order to execute distillation, a spirits producer must use an already fermented beverage as a base product. These initial materials are selected based on the desired final spirit. For example, whiskey is essentially produced from a beer base, which is made by fermenting various grains. (The types of grain depend on the style of whiskey being produced.) Gin is also commonly produced using grain-based alcohol, while vodka can be made with grain-based, fruit-based or potato-based alcohol.
Certain processes are used to prepare this base, called the mash, depending on the raw material the producer is working with. For example, starchy grains are milled and pressed, which makes the starches and sugars more prepared for the next steps of the process, whereas sugar-laden grapes are crushed and pressed.
With starchy grains, the grains are reduced to a meal-like substance to better execute the mashing process. Mashing incorporates mixing and wetting the base material to allow for optimized enzyme activity, which ultimately converts starches into easily fermentable sugars. In short, mashing breaks the coatings of starch cells, which prepares the material for the next step of the process.
With regard to fermentation itself, the equation is pretty simple: Yeast plus sugar produces alcohol and CO2. This fermentation equation is always the same and does not change, no matter what type of the raw material is used, be it grains, grapes or other fruits and produce. Fermentations can be done with either native yeasts or cultivated yeasts, the former of which are executed with naturally present yeasts found on base materials and/or in cellars, whereas cultivated yeasts are purchased strains added to the base to move the process along.
After the base alcohol is made, the next, and most crucial, step to making spirits is distillation. Distillation is the process of separating alcohol from water via evaporation and condensation. The base alcohol is heated, and certain parts of it are captured. This process purifies and concentrates the remaining alcohol, which will ultimately be the final spirit produced.
Distillation is done in stills. The two most commonly used stills are continuous stills and pot stills. Stills are equipped with three parts: the still (or retort), which heats the liquid, the condenser and the receiver, which collects the distillate at the end of the process.
The mash, or fermented base spirit, is transferred to the still and heated to a low temperature, which first vaporizes the alcohol. Because alcohol has a lower boiling point than water does, it can be evaporated by itself, collected and then cooled back down into a liquid, which then has a much higher alcohol content than when it first started. Numerous distillations can be done prior to the next step of the process, and depending on the style of spirit being made, multiple distillations, as well as distillation to a minimum proof, are often required.
Each style of spirit, depending on where it's made and which type of labeling it will be given, has different aging requirements. Certain types of spirits need to be aged for a minimum period of time, whereas some are bottled almost immediately after distillation. Others need to be aged in particular vessels.
Many distillers choose not to bottle their spirits at cask strength and will dilute them prior to the aging process. This is simply done by adding water to the spirit. This process generally renders the resulting alcohol “easier drinking” to most consumers.
To better understand spirits requirements, let’s use bourbon as an example. Bourbon must be produced in the United States and made from a mash bill with a minimum of 51% corn, distilled to no more than 160 proof (80% ABV), and it must age in new, charred oak barrels (which it cannot enter at higher than 125 proof). Most spirits have similar, if not even more stringent, requirements.
5. Blending and Beyond
After the aging process, there are plenty of additional optional steps that distillers can take to craft their spirits. Many distillers blend various spirits together to create a consistent flavor profile for their brand year after year. Others add coloring agents to change the hue of their spirit. Many distillers will also filter their spirits for a number of reasons prior to bottling them and releasing them to the market.
Once the spirits are aged and/or filtered, the liquid is bottled and ready to be packaged. Distilled spirits are bottled, labeled and sealed in a vessel, which can be glass, ceramic or a number of other materials, and are sealed with various styles of closures, including corks, screw caps and more.
Contrary to wine, spirits are generally believed to not improve with bottle aging and are usually sent straight to market after bottling. The relatively high ABV in spirits acts as a natural preservative, meaning the liquid’s shelf life is significantly longer than that of beer or wine once a bottle is opened. They can be enjoyed over a significant length of time—or for as long as you can make them last, that is.