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 Although originally made exclusively from sturgeon, especially beluga, in 1795 an invention by William Murdoch facilitated a cheap substitute using cod.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
Yeast in winemaking and amino acids or YAN) but also minerals (such as magnesium) and vitamins (such as thiamin and riboflavin) that serve as important growth and survival factors. Among the other nutritional needs of wine yeast: Many of these nutrients are available in the must and skins of the grapes themselves but sometimes are supplemented by winemakers with additions such as diammonium phosphate (DAP), freeze-dried micro-nutrients (such as "Go-Ferm" and "Ferm-K") and even the remnant of dead or extracted yeast cells such that the fermenting yeast can break down to mine for available nitrogen and nutrients. One historical winemaking tradition that is