A form of pure gelatin, commercially prepared from fish bones. The best quality is made from the bladder of the sturgeon and other fish. It is white, iodorous and tasteless. Under the name fining, it is used clarifying wines, beers &c. It is an effective substitute for white of an egg in royal icing.
From The Baker’s ABC by John Kirkland, formerly Head Teacher of National School of Baking, published 1927 by Gresham