Using a sharp paring knife, cut out and discard the core from the cabbage, including about 1 inch around it. Remove and discard any bruised outer leaves. Place a wire rack in rimmed baking sheet. In a large pot over high, boil 3 quarts water, the vinegar, bay, peppercorns and 3 tablespoons salt. Add the head of cabbage, submerging it so water flows into the hollow. Cover and cook until the outer leaves float free and the thickest part of their ribs begin to soften, about 8 minutes. Use tongs to transfer the leaves to the rack to drain. Continue to cook the cabbage, transferring leaves to the rack as they separate, until most of the head has been used and only the very center remains; discard the unused portion. Cool the leaves completely.