In a very large pot combine beer and lemon with 3 cups water. In a coffee grinder or spice mill, grind spices to a coarse powder; add to pot. Bring to a boil over medium-high heat, reduce heat to medium and simmer vigorously, 10 minutes. Add crabs and cover pot tightly. Bring to a boil and simmer 8 minutes. Serve on lots of newspapers with a small hammer, picks and lemon.;