Combine vinegar, water, 1/3 cup Old Bay, garlic and peppercorns in a large soup pot. Bring to a boil over medium high heat.
When water is rapidly boiling, add shrimp, cover and cook 2 to 4 minutes (until shrimp are just pink).
Immediately drain shrimp, place uncovered in a bowl and refrigerate (at least 30 minutes) until ready to serve.