Whisky makers tend to obsess over the colour of their product. That’s why some whisky makers add a touch of caramel to whisky in hopes that the darker spirit will lead to more sales. With chill filtration, the goal is to produce a liquid that sparkles with colour.
Chill filtration removes fatty acids, esters, and proteins that clump together at cold temperatures. When clumped together, the molecules are visible in the form of a cloudy tinge. This cloudiness is especially apparent when the alcohol content is below 46% ABV. Add ice to an unfiltered bottle of scotch, and you’re likely to see it. The argument against chill filtration is simple—chill filtration removes molecules that contribute to the flavour of the whisky. Further, it prioritizes vanity over flavour.
While this is not likely to settle the issue, a new study has concluded that chill filtration does not affect the taste of whisky. Whisky.com sent 12 whisky samples to 111 whisky experts in Germany. The samples were paired into 6 groups where one was chill filtered and the other was not. The pairs of whiskies were otherwise identical. Not only were these whisky experts unable to pick-out which whisky was chill filtered, they ranked the paired whiskies the same for quality and flavour.
Chill filtration is more of a barometer for the character of the distillery, than the taste of the whisky. Distilleries that use chill filtration are meeting the visual expectations of a richly appearing whisky. Distilleries that do not filter their whisky tend to bottle at a higher alcohol content to an audience less likely to mix with ice.
I will admit that I am a touch surprised chill filtration had no affect on the flavour as observed in this study. There are many important steps in the whisky making process, and this is just one. There are plenty of excellent distilleries that do and don’t chill filter. This is neither good nor bad. When it comes to this label, it tells me more about the distillery and their target audience than the flavour profile of the whisky.
For more in-depth information on factors that affect the flavour of whisky, labels, and what they mean, order my book: The Whisky Cabinet.