Complex sentence: Modern oyster stouts may be made with a handful of oysters in the barrel, hence the claim of one Dublin establishment the Porterhouse Brewery that their award winning Oyster Stout was not suitable for vegetarians.
Split into simpler sentences: Modern oyster stouts may be made with a handful of oysters in the barrel. Hence the claim of one Dublin establishment the Porterhouse Brewery that their award winning Oyster Stout was not suitable for vegetarians.