Preparing Whisky For Bottling - Flocculation and Filtering
When you next pick up a bottle of our whisky, invert it or give it a little shake. If you are lucky enough you might see a hazy little cloud of something.
What you are seeing is what we call the 'essence' of the whisky. To be precise it is the naturally occurring oils and proteins that provide an enormous amount of the flavour, mouth-feel and the finish of a great whisky.
In a cask strength whisky these oils and proteins are in suspension in the liquid and you never see them but here’s the thing!
When water is added to alcohol a reaction takes place and this reaction can cause some of those proteins and oils to come out of suspension. This can create a cloudiness in the whisky or a little bit of fluffy material that sits on the bottom of the bottle and so these solids (now called flock) need to be removed.
Why do they need to be removed if they contribute so much to the whisky?
The answer is simply a marketing one. Removing them makes the product "look" better in the bottle.
Large overseas distilleries use a process called chill filtering to remove flock. This process can remove a large percentage of the whisky's flavour and colour and it is not a process we follow.
We leave the diluted whisky in settling containers for as long as it takes for the heaviest components to settle to the bottom. This process that can take anything from several weeks to some months and any bump or shake will stir up the flock and if that happens we have to start the settling process all over again.
When the settling process has finished we (very, very carefully) syphon the whisky from above the flock.
This sort of natural settling process does not remove all those oils and proteins and that means we keep more of the mouth-feel, colour and flavour that existed when the whisky came out of the cask.
So you have this fluffy cloud-like flavour-ball that is perfectly natural and is meant to be in whisky. If you simply give the bottle a shake the flock will dissolve back into the whisky and return the flavour and texture that existed in the whisky originally.