2 pounds ice
1/2 ounce bay leaves (about 48 leaves)
1 cup paprika
1 cup celery salt
2 tablespoons cayenne
Two 12-ounce bottles of lager beer
3 cups apple cider vinegar
Rinse the crabs with cool water and transfer them to a large cooler. Top with ice and let sit until the crabs are still about 1 hour.
Meanwhile, to make the seafood seasoning, grind the bay leaves in a spice grinder until finely ground. Transfer to a bowl and stir in the paprika, celery salt, and cayenne.
Pour the beer into a 36-quart stockpot with a basket insert and add the vinegar, 2 tablespoons of the seafood seasoning, and 6 cups water. Stir to combine. Add the steamer basket (the liquid should be below the basket), cover, and bring to a boil over high heat.
Put 12 crabs in a single layer, shell-side up, on the steamer rack. Sprinkle liberally with about 1/4 cup seafood seasoning. Repeat the process, layering, and sprinkling, with the remaining crabs and seasoning. Cover and steam until the crabs are bright orange all over (there should be no traces of blue or green), 20 to 25 minutes.
Transfer the crabs to a large platter or rimmed baking sheet–or spread them out directly on a table covered with butcher paper — and serve with crab mallets for cracking the shells.