Grand River Beer - Cask Conditioned is Not Vegan Friendly

Company email:
"Our beer is 'primarily' barley malt (we use 7 different varieties), water, yeast (a live micro-organism that grows on sugar with the by-product of alcohol and CO2 and then is filtered out of our beer) and hops. The sole exception we have to this point is our Highballer Pumpkin Ale which has pumpkin in both the mash and the boil and also cinnamon, vanilla, cloves, ginger and allspice in the beer. Your one product to watch out for in all craft beers is cask ale or 'real ale' which is served out of bunged firkins (40.9 litre kegs) through hand pull beer engines. All cask ale is likely to be fined with isinglass finings (made from the swim bladder of sub-tropical fish) as ours is as well."