November 6, 2015 – A lot of strange things go into our food and drink behind the scenes. Who knew that the venerable Guinness has been using fish bladders for over 250 years to settle the yeast in its famous porters and stouts. This puts the lovely beverage out of bounds for committed vegetarians and vegans.
The technical name is isinglass, a product made of the dried air bladders of freshwater fish, which probably won’t make you feel any better. But ignorance was bliss so just keep repeating isinglass, isinglass, isinglass. It is also called a “fining” ingredient allowing brewers to clarify beer quickly. (Fining agents are also used in wine making.) The yeast will clarify on its own but it takes time so isinglass is used to speed up the process of flocculation, a fancy way of describing yeast forming blobs, which settle at the bottom of the barrel. It doesn’t change the flavor or the texture but tiny fragments of fish could remain in the brew and vegans find this offensive.
Vegans have been petitioning Guinness to change its ways. Whether the company has succumbed to the pressure or whether they have found “a new filtrations asset” as company spokesman recently described, no one will know the difference. It will taste exactly the same and fish bladder producers will be looking for a new market.