For this very delicate dessert, use bottled spring water and a light, good-quality sauternes or barsac. The peaches shouldn't marinate too long, so make them in the afternoon for dinner that night.
- 1 bottle (3¼ cups) sauternes or barsac
- ½–1 cups sugar
- 4 large, ripe, unpeeled white peaches
Combine sauternes or barsac, 2 cups bottled water, and sugar in a deep saucepan and bring to a simmer over medium heat.
Lower peaches into liquid and blanch just until skins have loosened, 1–3 minutes. Remove peaches with a slotted spoon, then carefully peel and set aside in a deep bowl.
Continue to simmer poaching liquid until it has slightly thickened and has reduced by half, about 30 minutes. Remove saucepan from heat and allow syrup to cool completely. Pour syrup over peaches and set aside to marinate for 2–4 hours.