How to Whisky: What is Chill Filtering?

Sunday, 26 October 2025 at 15:05

You often see the term ‘non chill filtered’ on a bottle of whisky. But what does this term actually mean? We delve into this term and explain precisely what it entails.

FAQ

What does non-chill filtered mean?
It means that the whisky is not cooled to filter out the acids and proteins.

Why is whisky chill filtered?
To maintain its clarity.

Is chill filtered whisky inferior?
No, although there is some debate about this.

Anyone who has put a bottle of whisky in the freezer or added a few drops of water to their glass may have noticed it: a sudden cloudiness in the spirit.

This is a natural phenomenon, where fatty acids and proteins suddenly make themselves visible. Yet this very aspect forms one of the most scrutinized techniques in the world of whisky: chill filtering.

What is chill filtering?

Chill filtering is a process that whisky makers use to keep their spirit clear and visually appealing. When whisky is strongly cooled, tiny particles of fatty acids, esters, and proteins form. These substances come from the grain and the wooden barrels in which the whisky has matured.

They can clump together and give the liquid a milky haze. This does not affect the quality or safety but might seem less attractive to some people.

To avoid the hazy look of whisky, distilleries cool the whisky down to around freezing point and then filter the spirit through fine filters. The clumps stay behind, while the clear liquid moves on. The whisky is then brought back to temperature and bottled.

Not Uncontested

Chill filtering is not without controversy. Some experts argue that along with the cloudy particles, flavorful oils, and aroma components are also removed. This would thus reduce the mouthfeel and complexity of the whisky.

Therefore, more and more distilleries are opting for non-chill filtered bottling. The whisky might appear somewhat hazy, but it avoids the debate over taste.