This is my favorite ice cream...even better if you can pick your own peaches Both the cooked peaches and the custard mixture must be cooled to 40 degrees before you churn them, so plan to prepare the custard the night before and refrigerator overnight. Of course fresh peaches are preferred but you can subsitute 2 cups frozen sliced peaches (defrosted) and replace the vodka with peach-flavored liqueur. The ice cream is at its peak when eaten within four hours of churning, although covered, it will keep in the freezer for up to two days. Cooking time indicated includes overnight cooling of the custard. Update: Was in a hurry so skipped the straining process and it was great ... we like the pieces of peach in the ice cream! Recipe from Cook's Illustrated.