I can take some of the crap that goes into beer but i didnt know the average pint has mustard and sulphur dioxide in it! 
I drank 'goon' in australia (stanley wines etc) which said may contain eggs and fish but when i buy beer it doesnt say that on the box anywhere.
In fact, there is nothing on a can of beer regarding contents or nutritional information (calories etc)
www.glutenfreebeers.co.uk
Green’s beers DO NOT contain any of the following allergens or products thereof: Gluten, Crustaceans, Eggs, Fish, Peanuts, Soya beans, Milk, Lactose, Nuts, Celery, Mustard, Sesame seeds, Sulphur dioxide and sulphites.

I drank 'goon' in australia (stanley wines etc) which said may contain eggs and fish but when i buy beer it doesnt say that on the box anywhere.
In fact, there is nothing on a can of beer regarding contents or nutritional information (calories etc)
www.glutenfreebeers.co.uk
Green’s beers DO NOT contain any of the following allergens or products thereof: Gluten, Crustaceans, Eggs, Fish, Peanuts, Soya beans, Milk, Lactose, Nuts, Celery, Mustard, Sesame seeds, Sulphur dioxide and sulphites.