If shrimp is frozen, thaw in a bowl of cold water for 20 minutes. Drain and set aside.
If fresh, rinse in cold water. Drain and pick out any shell pieces. Set aside.
Place water, beer, vinegar, lemon juice and Old Bay Seasoning in medium stock pot (4-6 quarts). Whisk together and bring to boil over medium-high heat.
Add shrimp to pot and cook for 2-3 minutes, just until shrimp curls up and turns pink.
Drain and serve immediately or refrigerate until ready to use.
Serve with cocktail sauce and lemon wedges. Shell before eating!