---------- Recipe via Meal-Master (tm) v8.02
       Title: Testing Jar Seals
  Categories: Canning, Information
       Yield: 1 guide
   After cooling jars for 12 to 24 hours, remove the screw bands and test
   seals with one of the following options:
   Option 1. Press the middle of the lid with a finger or thumb. If the lid
   springs up when you release your finger the lid is unsealed.
   Option 2. Tap the lid with the bottom of a teaspoon. If it makes a dull
   sound, the lid is not sealed. If food is in contact with the underside
   of the lid, it will also cause a dull sound. If the jar is sealed
   correctly, it will make a ringing, high-pitched sound.
   Option 3. Hold the jar at eye level and look across the lid. The lid
   should be concave (curved down slightly in the center). If center of the
   lid is either flat or bulging, it may not be sealed.
   * USDA Agriculture Information Bulletin No. 539 (rev. 1994)
   * Meal-Master format courtesy of Karen Mintzias