In my opinion, the interesting news from last week wasn't so much the announcement that Guinness will soon be vegan, but all the reactions I saw on Facebook and Twitter from people surprised to learn that it wasn't vegan already. Just what has been lurking in your black pint of Guinness all these years?
Don't worry — Guinness hasn't been slipping beef steaks into their secret formula. Rather, the culprit is an ingredient called isinglass, which is made from dried swim bladders from fish. Isinglass is a clarifying agent (not a flavoring ingredient) used to remove leftover bits of protein and yeast that would otherwise affect the appearance of the beer when served. Very little to no isinglass actually remains in the beer after it has done its job, but even so — definitely not vegan.
So now Guinness is joining the 21st century and switching over to mechanical filtration processes that will no longer rely on fish bladders. Guinness for all! But will it taste the same? Only time will tell.