Definition: Collage

Traditionally, red wines were fined using fresh beaten egg white (at least four eggs per 225-litre barrel), but this process is now rarely used, although some large châteaux still advertise it. Bordeaux has taken advantage of egg yolks to create a famous little cake called a cannelé. White wines are more commonly fined with fish glue or bentonite (clay from Wyoming). The casein used comes from milk. The use of fresh blood is now prohibited, so only dried animal blood is used. In recent years, glues based on bovine or porcine gelatin have also been used. These are produced using bone carcasses from slaughterhouses and hides from tanneries, which are treated with acid and lime. This treatment eliminates the risk of Creutzfeldt-Jakob disease contamination in wine.