Activated Carbon is made mainly from charcoal using a number of processes usually involving heat of up to 900 degrees Celsius producing a product in which one gram generally has a surface area in excess of 500 square metres. The millions of microscopic channels in every gram of carbon allow impurities to trapped and allowing almost pure product to past through.
Impurities in Alcohol
Alcohol made at home using good ingredient and equipment will only contain tiny amounts of impurities. These impurities are harmless but may contribute to a bad taste or smell These tastes and smells are often contribute to the complex tastes of some whisky’s and bourbons but from a home distillers point of view especially when using essences they are better removed.
There are many types of carbon filters on the market but they all work the same way. With granulated carbon the filter consists of a tube filled with carbon with porous pad at the bottom to stop the carbon washing out and a tap to restrict the flow of alcohol to the desired rate. Many new type filters have carbon cartridges which saves dealing with messy carbon granules making the process a bit easier.
Rate of Flow
If the Spirit has only a slight smell it can be filtered at a slow dribble, a smelly spirit my need to drip through the filter. If the spirit still smells after being put though the filter put it through again. The smell of alcohol is not the smell I am talking about here.