Clarification is the name given to any process where solids are removed from wort or beer to give a clear liquid. Wort clarification is important because beer produced from clear or “bright” wort tends to be of higher quality. Wort clarification takes place in the brewhouse after it has been boiled in the wort kettle or copper. It may involve a “whirlpool” if hop extracts or pellets are used, or a “hop back” when whole leaf hops are used. Worts that have not been clarified may be slow to ferment, and the resulting beer may be difficult to filter, or may be difficult to clarify in cask using finings.
Beer clarification can involve different processes. Filtration is the most commonly used. Centrifugation is another method of clarifying beer. In this process excess quantities of yeast and protein are removed from beer in the brewery before filtration. Beers are easier to filter if excess solids are removed before final filtration. In traditional cask beer, finings agents such as isinglass are used to sediment yeast and protein during a clarification process that takes place in a cask.