When you follow whisky blogs and news, you may have noticed the words Chill Filtered regularly popping up. Now, if you found yourself wondering what chill filtration is. Or perhaps found yourself wondering why people seem to put such high stock in un-chillfiltered whisky? Then, you’ve come to the right place.
What is chill filtration?
Chill filtration is the process of cooling down a whisky (before bottling it) to the point that some of the fatty acids, proteins and esters solidify. Once solidified these “undesirables” are filtered out. I hyphenated “undesirables”, because whether these elements in your whisky are undesired is up to debate. What is not up to debate, is the fact that none of these elements are hazardous to one’s health.
Why chillfilter a whisky?
Distilleries use chill filtration because when these fatty acids, proteins and esters solidify, they may cause an unappealing “cloudiness” in your bottle. Keep in mind that this will only happen if you store your whisky cold. And the “cloudiness” will disappear when the liquid returns to room temperature. Nonetheless, many people who see their brand-new bottle turning cloudy (or hazy) would run back to the store to get their money back.
Also note that the cloudiness only appears in whiskies bottled under 46,3% ABV (92,6 proof). But that doesn’t mean distilleries never chill filter these higher proof whiskies. Because the cloudiness can still appear in these “high proof” un-chillfiltered whiskies. After all, some of us like to add an ice cube or a drop of water or two. And if, by doing so, we bring the ABV below 46,3%? Then the cloudiness may appear yet again. And thus, chill filtration has become widely implemented, to prevent people from thinking there is something wrong with their whisky.
The un-chillfiltered revolution
Some distilleries choose to refrain from chill filtration (in some cases from their entire line-up). They do so because filtering out these “impurities” from their whisky, may also filter out some of the flavours these elements add to your dram.
It was Burn Stewart’s (Bunnahabhain, Deanston, Ledaig and Tobermory) former master blender, Ian MacMillan, who persuaded his company in 2010 to raise the ABV of all their single malts to 46,3% and to stop using the practice of chill filtration. In his opinion the flavours that took so many years to develop, should not be taken out of a whisky just to make it look prettier. He found that Bunnahabhain, for example, had a far more robust character un-chillfiltered. And so, he became an advocate for all un-chillfiltered whisky, hoping to create a revolution among distilleries.
If you wanna read more about Ian Macmillan and his views on chill filtration I can greatly recommend checking out the article: Stop Chill-Filtering Whisky – by Gavin D Smith for scotchwhisky.com. He sketches a clear image of just how important Macmillan was to the un-chillfiltered revolution.
Over the years MacMillan found many supporters, and many other brands added un-chillfiltered options to their line-up. Signatory (for example) even gave it a whole category, aptly named the Un-Chillfiltered Collection. And following the distilleries, more and more afficionados started putting stock in un-chillfiltered whiskies.
To chillfilter, or not to chillfilter
Does this mean that you’re always better of choosing an un-chillfiltered whisky? Does it mean the whisky is of a higher quality?
It’s important to remember that even Ian MacMillan states that not all single malts may yield the same results that Bunnahabhain did. There have also been blind tastings that suggest chill filtration has little impact on flavour. So, it doesn’t necessarily mean that un-chillfiltered whisky is better. In some cases, it will hardly make a difference. With other cases, you might get a superior whisky. In the end, unless you can buy the same exact whisky chillfiltered and un-chillfiltered and taste them side by side, you’ll never know what difference it really makes.
What it does give you though, is a more natural whisky. Just like we like to have our whiskies with natural colour, having them un-chillfiltered means we get closer to the “natural” taste of the whisky. And how important that is, is up to you. Personally, I’m happy I get to taste more and more un-chillfiltered whiskies. But I won’t disregard the ones that are not.