One of the most critical steps in canning is sterilizing your jars. Sterilizing will help keep any unwanted bacteria from forming in your amazing homemade peach preserves. Step 1: Wash jars thoroughly in hot soapy water or boil them on the stovetop. Step 2: In a large pot, bring water to a simmer add jars, lids, and caps to the water. Bring water to a boil and boil them for 10 minutes over medium heat. Step 3: Place sterilized jars upside-down on clean towels, paper towels, or dishcloths (to prevent direct contact) while you prepare other ingredients. Now you have correctly sterilized jars for canning, make sure everybody who's home knows wot stay clear of your sterilized jars.