What is Chill Filtering?

The process of cold or chill filtering is routinely carried out on almost all bottled Scotch whisky, malt or blend. The process involves chilling the whisky down to a temperature of 4 degrees Celsius, which will bring out of solution certain types of compounds (mainly lipids), which are then filtered out of the solution. If this is not carried out, the compounds can come out of solution under certain storage conditions in bottle, giving the spirit an unattractive, hazy appearance.

Occasionally, if whisky is bottled at cask strength, this process is not carried out, and if water is added to such whisky in a glass, the whisky can turn slightly cloudy. There is no danger in drinking whisky like this, and indeed, true whisky aficionados will always say that this is the best way in which to enjoy scotch.

The process is, therefore, carried out solely for the appearance of the bottled product, particularly at lower strengths (e.g. 40% abv), at which the lipids more readily come out of solution.

Generally, whisky that has not been chill-filtered has more mouthfeel and, in some cases, can be slightly more full flavoured. It is as close as possible to drinking whisky "straight out of the cask."