Combine the wine, water, sugar, and peppercorns in a deep nonreactive saucepan. Do not use a plain aluminum or iron pan. Bring to a boil and simmer gently for 5 minutes. Add the pears and simmer for 15 minutes.
Remove the pears from the saucepan and transfer them to a bowl.
Boil down the cooking liquid until it is reduced by about half. Pour over the pears and refrigerate for at least 4 hours or overnight.
Serve the pears in deep dishes with the poaching liquid.