Black Iris Brewery has some vegan options

Company email (May 2018)
"Keg remains 100% Vegan
Cask will always state on the Label
Cans - all our canned beers are unfined, but we do use lactose (Milk Sugar) in some beers. However, this will be stated in the allergens list on our ingredients. Currently only Rise and Shine and Cosmic Cream contain lactose."

Company email (January 2018)
"Its a bit hit and miss but I'll try and guide you through it.

"Our cask beer is usually fined with isinglass finings. We do, however, do some vegan cask on special request. The usual venue for this is the Angel Microbrewery on Stoney St.

"Nearly all our keg beer is vegan. This is only the exception with a couple of beers that contain lactose but all our allegens are stated on all our cask/keg labels. I know this is a bit hit and miss but as we brew many different styles, it is quite often the case that the lists are always changing."

Company Tweet (July 2015):
"In fact apart from our milk stout, all our keg beer is 100% vegan ie no isinglass finings."
https://twitter.com/BlackIrisBrewer/status/616164085944700928

Company Tweet (April 2013):
"Hi, is your Witbier vegan?
@BlackIrisBrewer: Hi, yes it is!"
https://twitter.com/BlackIrisBrewer/status/328847536133648384