The Best and Worst Ways to Filter Whiskey

Filtration is one of the most controversial steps in the whiskey-making process. In fact, it’s so controversial that many distillers and at-home whiskey makers don’t even discuss it. Nevertheless, just about every whiskey you can buy is filtered in some way. What are the best ways to filter whiskey, and are there any methods to avoid? Keep reading to learn more. 

What Does Filtration Even Do?

Filtration affects whiskey in two very important ways. 

• Clarity: Whiskey spends time aging in a wooden barrel, and it leeches many of the tannins from the wood in the process. Those tannins impart flavor and color, but they can also leave the spirit looking a bit cloudy – something that isn’t exactly appealing to whiskey aficionados. Filtration clarifies the whiskey and makes it more appealing when it’s packaged in its bottle or poured into your favorite rocks glass. 
• Flavor: Though it occurs to different degrees, filtration absolutely affects the flavor of the whiskey. In fact, a handful of luxury whiskey brands don’t filter their spirit at all because they claim to prefer flavor to aesthetic appeal. This is a hotly debated topic, and there’s no right or wrong preference in terms of filtration method and taste.

Types of Whiskey Filtration

Distillers use one of three methods to filter their whiskey: cold filtration, non-chilled filtration, and charcoal (or carbon) filtration. Each one is slightly different, and some say the method used impacts the product’s final taste. 

Cold (or Chill) Filtration

Distillers use cold or chill filtration when they want to separate the fats, proteins, and oils picked up during the distillation or aging process that can lead to cloudiness. To do it, they chill the whiskey to somewhere between 41 and 50 degrees Fahrenheit, then pass it through a range of filters that trap particulate matter of different sizes. At the end of the process, the whiskey is much clearer. However, because cold filtration removes some of the elements present in the whiskey that can add to its flavor, some say that cold filtering can dilute the spirits flavor. Cold-filtered whiskey tends to have a smoother and lighter taste than their non-chill filtered counterparts. 

Non-Chilled Filtration

When whiskey is filtered without being chilled, it retains some additional flavors and aromas. The fatty acids that congeal during the chilling process remain evenly distributed in the charcoal filtration method, and they provide some excellent finishing notes in the finished product. These whiskeys are usually described as sharper, heavier, and thicker. 

Charcoal Filtration

Many distillers use charcoal as a natural filter, especially since charcoal filtration is a trademark of the Tennessee whiskey production process. For example, the “Lincoln County Process” uses charcoal made from sugar maple trees since it lends some additional flavor, it’s widely available, and it’s indigenous to the Midwestern region where almost all of the bourbon whiskey in the country is produced. The sugar maples are air dried and then burned in ricks before being ground down into small chips. Then, the chips are placed in mellowing vats, the whiskey is poured over them, and the entire solution is left for several days. 

Filtering whiskey makes it visually clearer, but many experts say it significantly dilutes the flavor of the whiskey with time. We recommend trying cold, non-chill, and charcoal filtered whiskeys at least once to see the difference for yourself. As always, remember to drink responsibly.