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 Although originally made exclusively from sturgeon, especially beluga, in 1795 an invention by William Murdoch facilitated a cheap substitute using cod.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 fish the codfish tastier. The Portuguese tried to use this method of drying and salting on several varieties of fish from their waters, but the ideal fish came from much further north. With the "discovery" of Newfoundland in 1497, long after the Basque whalers arrived in Channel-Port aux Basques, they started fishing its cod-rich Grand Banks. Thus, ' became a staple of the Portuguese cuisine, nicknamed ' (faithful friend). From the 18th century, the town of Kristiansund in Norway became an important place of purchasing "bacalhau" or "klippfisk" (literally "cliff fish", since the fish was dried on stone cliffs by the