In a large stockpot (about 12 quarts), combine the water, Old Bay seasoning, lemon halves, onion, garlic, thyme, parsley, bay leaves, peppercorns, and beer. Bring the mixture to a boil over medium-high heat over an outdoor cooker, or on the stovetop.

Add the potatoes to the pot. Cook for about 10-12 minutes or until the potatoes are just beginning to become tender.

Add the corn and sausage to the pot. Cook for another 5-7 minutes.

Add the shrimp to the pot. Cook for 2-3 minutes, or until the shrimp are pink and opaque. No need to wait for the water to come to a boil before timing the shrimp as the hot liquid will cook the shrimp.

Drain the boil, discarding the liquid. Transfer the shrimp, potatoes, corn, and sausage to a large serving platter or spread them out on a newspaper-lined table for a more casual presentation. Pour melted butter over the shrimp mixture and stir to evenly coat.

Garnish with chopped fresh parsley. Sprinkle additional Old Bay seasoning to taste or season with salt, to taste.

Serve immediately with melted butter and lemon wedges on the side.