Isinglass Isinglass Isinglass () is a substance obtained from the dried swim bladders of fish. It is a form of collagen used mainly for the clarification or fining of some beer and wine. It can also be cooked into a paste for specialised gluing purposes. Its origin is from the obsolete Dutch "huizenblaas" – "huizen" is a kind of sturgeon, and "blaas" is a bladder, or German "hausen blas", meaning essentially the same. Although originally made exclusively from sturgeon, especially beluga, in 1795 an invention by William Murdoch facilitated a cheap substitute using cod. This was extensively used in Britain in
Dried and salted cod Other names include "ráktoguolli/goikeguolli" (Sami), "klipfisk/klippfisk/clipfish" (Scandinavian), "stokvis/klipvis" (Dutch), "saltfiskur" (Icelandic), "morue" (French), "saltfish" (Anglophone Caribbean), "bakaljaw" (Maltese), "labardan" (Russian). The fish is beheaded and eviscerated, often on board the boat or ship. (This is feasible with whitefish, whereas it would not be with oily fish.) It is then salted and dried ashore. Traditionally the fish was sun-dried on rocks or wooden frames, but modern commercial production is mainly dried indoors with electrical heating. It is sold whole or in portions, with or without bones. Prior to the collapse of the Grand Banks (and other) stocks due to overfishing, salt