Step 1

Combine the beer and vinegar with 1 cup of water in a very large pot. Add a steamer insert and bring the liquid to a boil over high heat. Add the crabs and 1/4 cup of the Old Bay and cook, covered, until the crabs are bright red, 20 to 30 minutes, depending on the size. Transfer the crabs to a large platter and sprinkle with the remaining 1/4 cup Old Bay.

Step 2

Serve the hot crabs with the Spicy Butter and lemon wedges on the side.

Step 3

Make the butter while the crabs cook: combine the butter, Old Bay, cayenne and garlic in a small saucepan over medium heat. Melt the butter, skimming off any foam that rises to the surface. Pour the melted butter into a small ramekin, leaving the milk solids in the saucepan.