1. Select fruit in its prime. Make sure not to can underripe or overripe fruit.
  2. Cook the fruit in a heavy-bottomed pan to avoid burning.
  3. Skim off the foam during cooking if you like, but you don’t have to; it won’t affect the taste.
  4. Choose easy-to-fill wide-mouth mason jars that close with flat caps and screw-on rims. Two good brands are Ball and Kerr.
  5. Buy new caps for every new sealing.
  6. Use a big pot with a fitted rack to boil the canned fruit, so the jars don’t touch the bottom.
  7. Be sure the jars fit easily in the pot. You will get better results if the rims don’t touch.
  8. Consider investing in a home pressure canner, which cuts the processing time in half. They are available at specialty kitchenware shops from about $60.
  9. Store preserves in a cool, dark place; sunlight can bleach out the color.
  10. Refrigerate canned foods after opening.