All you vegans out there, beware:
Guiness says that “minute quantities” of an animal product called isinglass could be in its beer.
Isinglass, a gelatine-like substance made from the air-bladders or sounds of fish like the sturgeon is added to cask beers like Guinness to help any remaining yeast and solid particles settle out of the final product.As the finings pass through the beer, they attract themselves to particles in the fermented beer that create an unwanted “haziness” in the final product and form into a jelly-like mass that settles to the bottom of the cask. While beer left untouched will clear on it’s own, isinglass speeds up the process and doesn’t affect the final flavor of the beer once removed.
[Happy St. Patrick’s Day! 😛 ]