Title: Tuna
 Categories: Fish, Canning
      Yield: 1 Text
 
 
  Tuna may be canned either precooked or raw. Preooking removes most of
  the strong-flavored oils. The strong flavor of dark tuna flesh
  affects the delicate flavor of white flesh. Many people prefer not to
  can dark flesh. It may be used as pet food.
  
  Note: Glass-like crystals of magnesium ammonium phosphate sometimes
  form in canned tuna. There is no way for the home canner to prevent
  these crystals from forming, but they usually dissolve when heated
  and are safe to eat.
  
  Procedure: Keep tuna on ice until ready to can. Remove viscera and
  wash fish well in cold water. Allow blood to drain from stomach
  cavity. Place fish belly down on a rack or metal tray in the bottom
  of a large baking pan. Cut tuna in half crosswise, if necessary.
  Precook fish by baking at 250 degrees F for 2-1/2 to 4 hours
  (depending on size) or at 350 degrees F for 1 hour. The fish may also
  be cooked in a steamer for 2 to 4 hours. If a thermometer is used,
  cook to a 165 to 175 degree F internal temperature. Refrigerate
  cooked fish overnight to firm the meat. Peel off the skin with a
  knife, removing blood vessels and any discolored flesh. Cut meat away
  from bones; cut out and discard all bones, fin bases, and dark flesh.
  Quarter. Cut quarters crosswise into lengths suitable for half-pint
  or pint jars. Fill into jars, pressing down gently to make a solid
  pack. Tuna may be packed in water or oil, whichever is preferred. Add
  water or oil to jars, leaving 1-inch headspace. Add 1/2 teaspoon of
  salt per half-pint or 1 teaspoon of salt per pint, if desired.
  
  Adjust lids and process following the recommendations in Table 1 or
  Table 2 according to the canning method used.
  
  Table 1. Recommended process time for Tuna in a dial-gauge pressure
  canner.
  
  Jar Size: Pints and Half-pints. Process Time: 100 minutes. Canner
  Pressure (PSI) at Altitudes of 0 - 2,000 ft: 11 lb.
                                  2,001 - 4,000 ft: 12 lb.
                                  4,001 - 6,000 ft: 13 lb.
                                  6,001 - 8,000 ft: 14 lb.
  
  Table 2. Recommended process time for Tuna in a weighted-gauge
  pressure canner.
  
  Jar Size: Pints and Half-pints. Process Time: 100 minutes. Canner
  Pressure (PSI) at Altitudes of 0 - 1,000 ft: 10 lb.
                                    Above 1,000 ft: 15 lb.
  
  ======================================================= === * USDA
  Agriculture Information Bulletin No. 539 (rev. 1994) * Meal-Master
  format courtesy of Karen Mintzias