Wait to wash fresh fruit until you are ready to use it. Fruit has a natural preservative (that dusty look that you’ll see most noticeably on grapes. Rinsing and then refrigerating can spur mold growth or other bacteria to grow on the fruit. Fresh peaches that are picked ripe will last in the fridge for about 3-5 days. Peaches won’t ripen further after refrigeration though, so be sure they are ripened first on the countertop by placing them in a brown paper sack (like the kind of paper sack you might pack your lunch in.) Refrigerate once ripe, then wash prior to eating.