Isinglass

The English word origin is from the obsolete Dutch huizenblaas – huizen is a kind of sturgeon, and blaas is a bladder,[1] or German Hausenblase, 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Although originally made exclusively from sturgeon, especially beluga, in 1795 an invention by William Murdoch facilitated a cheap substitute using cod.

In modern British brewing all commercial isinglass products are blends of material from a limited range of tropical fish.

[7] A beer-fining agent that is suitable for vegetarians is Irish moss, a type of red algae containing the polymer chemical carrageenan.

Eggs were submerged in solutions of waterglass, and a gel of silicic acid formed, also sealing the pores of the eggshell.

A small amount of gum tragacanth dissolved in water is added to the strained isinglass solution to act as an emulsifier.

When repairing paint that is flaking from parchment, isinglass can be applied directly to an area which has been soaked with a small amount of ethanol.

Here, isinglass is similar to parchment size and other forms of gelatin, but it is unique in that as a dried film the adhesive can be reactivated with moisture.

This adhesive is advantageous in situations where minimal use of water is desired for the parchment as the isinglass can be reactivated with an ethanol-water mixture.