What is Chill Filtration?
If you’re anything like I am you’ve most probably spent a fair amount of time pouring over your whisky labels trying to learn more about the spirit in your glass, you might have also noticed that the words non chill-filtered are generally accompanied by a higher ABV but had no idea why. You might have noticed that they’re also generally speaking better whiskies, a fantastic example would be the Glenfiddich 15 Distillery Edition I’ve recently reviewed.
Put in simple terms chill filtration is a cosmectic process whereby tasty fatty acids left behind by the grain are removed to give a clearer looking spirit at lower ABV. As these acids are soluble in high (44%+) alcohol you would only notice the hazing if the spirit was bottled arounnd 40% ABV or if you add water:
In the glass on the left the reduced ABV (below 44%) has caused the esters with a longer molecular chain length such as lauric, palmitic and palmitoleic acid to react with the acid fats and cause a hazing of the spirit. The below video by the fantasic Ralfy (if you’ve not already I highly recommend subscribing to his YouTube Channel) explains the process and the consequences of chill filtration and why it might work for blends but is tragic for malts!