Spirits - Physical Hazes

Physical hazes and their associated precipitation problems are much more difficult to deal with. These physical hazes require liquid/liquid separation as opposed to the elimination of solid particulate matter, usually associated with filtration. The liquid phase requiring removal from whisk(e)y comprises ethereal oils. The problem of their removal is made more complex because they may show up as a haze in bottled product, despite the fact that the product may have been perfectly bright at the time of bottling.

Whisk(e)y shipped to countries with low ambient temperatures may throw a haze due to the temperature reduction. For this reason, most whisk(e)y is filtered after chilling to avoid this problem. Typical temperatures used vary between zero to plus 4 degrees C.

The sheet filtration process used in the whisk(e)y industry may be in lenticular or sheet filter format and either single or dual step:

Single step filtration takes place at 0 - 4 degrees C when bottling at 20 degrees C and typically uses Carlson's specially developed NA45K/NA70K sheet.