The substance is added to some beers during the brewing process to make them beautifully clear. In England, a lot of beer used to be clarified in this way. Even today, the ‘real ales’ are still clarified with Isinglass. But also the most important Belgian lager brewers used the process with fish glue until 2009. Vegetarians naturally object to the use of fish glue in beer. That is why brewers nowadays use other substances, such as gelatine. Colla Piscium can also be used to clarify wine.