If you're a vegan, and drink Guinness,....you may not want to read this!
As St. Patrick's Day creeps closer, so does the promise of corned beef and cabbage, green beer and, of course, Guinness. But some vegetarian and vegan revelers might want to reconsider that thick, creamy Irish stout -- it could contain trace amounts of fish bladders.
Smithsonian.com's Food&Think blog published on Wednesday an in-depth explanation of isinglass, a form of collagen culled from a dried swim bladder, an internal fish organ that helps regulate buoyancy in water. It's used in a process called fining -- when unwanted leftovers, like solid particles and degenerated yeast cells, are removed from the brewing process. These elements settle on their own to the bottom of a cask in a jelly-like clump, but isinglass quickens the process and makes them easier to remove.
The use of isinglass as a fining agent isn't exactly new, and it's not exactly news. While many beers and wines use gelatin instead of isinglass these days (those beverages aren't vegan, either), Guinness still uses it in much the same way it has since the mid- to late-19th century. And publications and blogs have been taking note of it for some time now.
Still, it remains largely unknown to the greater public, likely because Guinness doesn't publicize it. Isinglass is not listed as an ingredient on Guinness' website, nor is it listed on the bottle. (In the U.S., alcoholic beverages are not required to list ingredients on labels.)
Link:http://www.huffingtonpost.com/2013/03/14/guinness-fish-bladder_n_2878165.html?utm_hp_ref=mostpopulary 
= new reply since forum marked as read
indeed
I've got to have my Guinness! It is one of my guilty pleasures.
My Husband brews a few stout recipes and one of them (I believe) is as good as Guinness, we even have the same sort of tap used to pour it.
That said, I know he does use chitosan (which uses things like shrimp and crustacean shells) as a clarifier, and has used isinglass -- that is fairly common when making beer. It's essentially a natural clarifier.
I can see I can understand vegans not wanted to drink this, but as far a vegitarians, the isinglass as well as the Chitosan do not stay in the beer when the final product is done. It acts like a magnet, as the article mentions for the unwanted blerg. It does indeed settle to the bottom and -- if one is brewing properly, it never enters the final product.
Something else interesting -- Most ciders are advertised as vegetarian -- they use these products to give a nice clear look to the final product. He makes a wonderful cider too -- We just finished a corny keg of a nice dry cider made from Maryland apples.
I think a lot of people would be surprised to find how many breweries use either isinglass or chitosan.
Alternatively -- Chitosan has been used as a rapid blood clotter. It is also known to be used as a way to block fat in the intestine.
As far as the fish bladder, On days like today, I agree, I can use all the bladder I can get!
Sláinte! 
Raine
I don't care for green beer.[img]
[/img]
It isn't a day for champagne. [img]
[/img]
What I really want is a scotch mist.
She would hate to read ohiosmith's OP. 
Maybe I should send her a link by email. 
I also like to drink it "Old World Style"
And it sure beats eating pig anus "squid" (#8). "Is it just me, Marge, or does this calamari taste like pigshit to you, too?"
