The history is murky, but legend has it that brewers in Victorian England discovered that the calcium carbonate in oyster shells made for a great clarifying agent in beer. Why anyone would be so pre-occupied with clarifying a pitch black brew is anyone's guess. Over time, brewers began adding the actual oysters to their beers with the logic that the bivalves would add a subtle brininess and make the roasty flavors pop. In Flying Dog's Pearl Necklace, the addition of oysters from the Rappahannock River lends a subtle note of maritime. Bonus: Proceeds from the beer benefit oyster recovery efforts in the Chesapeake Bay. []