Chill filtering is a method in
whisky making for removing residue. In chill filtering, whisky is cooled to between and passed through a fine
adsorption filter. This is done mostly for cosmetic reasons — to remove cloudiness — however by many whisky drinkers it is thought to impair the taste by removing the details which differentiate between the many distilleries.
Method
Chill filtering prevents the whisky from becoming hazy when in the bottle, when served, when chilled, or when water or ice is added, as well as precluding sedimentation from occurring in the bottles. It works by reducing the temperature sufficiently so that some
fatty acids,
proteins
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
and
esters (created during the distillation process) precipitate out and are caught on the filter. Whiskies are usually chilled down to .
Factors affecting the chill filtering process include the temperature, number of filters used, and speed at which the whisky is passed through the filters. The slower the process and the more filters used, the more of the distillates will be collected, but at increasing cost.
This process generally impacts the taste of the whisky, by for example, removing peat particles that contribute to the complexity, subtlety and smokiness of the flavour. Some
distilleries pride themselves on not using this process. Non-chill-filtered whisky is often advertised as being more "natural", "authentic", or "old-fashioned". For example, the
Aberlour Distillery
Aberlour is a distillery of Speyside single malt Scotch whisky, in Aberlour, Strathspey, Scotland, at the confluence of the Lour Burn and River Spey near Ben Rinnes.
History
James Fleming (1830-1895) was born and baptised on the first day of ...
's distinctively flavored
A'bunadh whisky,
Laphroaig's ''Quarter Cask'' bottles,
Kilchoman' s Machir Bay, and all of
Springbank distillery's whiskies are not chill-filtered and are advertised as such. There are also a number of specialist whisky suppliers, such as the
Scotch Malt Whisky Society, that provide bottlings from a wide range of distilleries without chill filtering.
Chemistry
Unfiltered whiskies chilled below a certain temperature can force some fatty acid esters out of suspension. In Scotch whisky these are usually agglomerations of
ethyl dodecanoate and
ethyl hexadeconate. Chill filtering removes these as well as
ethyl palmitoleate from the whisky, although complete removal of ethyl dodecanoate is not seen as desirable as it tends to contribute positively to the character of a spirit.
References
{{DEFAULTSORT:Chill Filtering
Filtration
Whisky