Guinness Goes Vegan: What You Didn't Know Was In Your Beer

Fish bladders have been used in some U.K. beers.

ByABC News
November 3, 2015, 3:54 PM

— -- Guinness beer has been iconic for centuries. But did you know that fish bladders are part of the brewing process?

This week, Guinness Brewing company announced that it will no longer use fish bladders (called isinglass) in an effort to allow vegetarians and vegans to enjoy the beer.

"Isinglass has been used widely within the brewing industry as a means of filtration for decades," officials from Guinness said in a statement. "However, because of its use we could not label Guinness as suitable for vegetarians and have been looking for an alternative solution for some time. We are now pleased to have identified a new process through investment in a state-of-the-art filtration system."

Isinglass is actually a gelatin made of fish bladders and since it's used in production, it's unlikely to leave any fishy taste behind.

Alastair Boase, owner of Macleodale Brewing Company in Van Nuys, Calif., said many of the big brewing houses have transitioned to larger filtration systems, but his company has continued to use isinglass because it's effective and low cost.

Newcastle Brown Ale also uses isinglass during the production process.