Canning tuna requires 10 to 15 pounds of pressure.
Tuna must first be cleaned well, deboned and sliced before canning. Then it can be placed in small sterilized canning jars with a little salt and olive oil. A pressure cooker is also needed to can tuna. The canning jars are cooked in the pressure cooker for just over an hour and a half. All jars that have not been sealed properly should be eaten immediately or refrigerated.
Fresh tuna should be used when canning tuna. The viscera, head, skin and bones must be removed. Skinless and boneless tuna can also be purchased at a local fish market. Some individuals also prefer to remove the dark lineage from the fish.
Tuna – fresh or canned – can contain relatively high levels of mercury.
The tuna must be cut into pieces after it has been cleaned well. Pieces that are one to two inches in size should be enough for canning tuna, as pieces that size fit easily in canning jars. Small 240-milliliter (8-ounce) canning jars should be used for canning tuna. Larger jars can promote bacterial growth, resulting in a spoiled product. All jars, lids and rings must be sterilized before canning tuna.
Some species of tuna – which provide the popular fresh and canned fish – can grow to over six feet in length and weigh hundreds of pounds.
New canning jars should be washed with soap and hot water before being sterilized. Immersing jars, lids and rings in boiling water is a method of sterilization. The pot can be removed from the heat after a few minutes and the jars can remain in the water until they are ready to be used. A person can also put all the parts of canning jars in a dishwasher with the hottest water possible.
Olive oil should be added when canning tuna.
The tuna chunks can then be added to the jar. When canning tuna, it is important to make sure that there are practically no air bubbles between the pieces. If necessary, smaller pieces of fish can be used to fill in the gaps between the larger pieces. Also, a 2.5 cm (1 inch) gap should be left between the top of the fish and the edge of the jar.
A generous amount of salt should be sprinkled on top of the fish. Other seasonings can also be used to infuse the fish with flavor. Garlic, rosemary and jalepeño peppers are some examples. Olive oil should be added to jars when canning tuna. Again, a space of about 1 inch should be left between the top of the fish and the oil and the rim of the jar.
When all the fish, spices and oil have been added, the lids can be placed on the jar. Metal rings should also be screwed on lightly. A few inches of water and a spacer should be added to the bottom of the pressure cooker, and it should be placed on the stove over high heat.
Tuna filled jars can be placed in the pressure cooker. They should be placed on the bottom of the pressure cooker in a circle. If there is enough space, another layer of canning jars can be placed on top of the first layer.
The pressure cooker lid should be closed tightly and locked in place. Canning tuna usually requires 10 to 15 pounds of pressure. Pressure can usually be regulated by increasing or decreasing heating. Tuna pots should be cooked for 90 to 100 minutes before removing the pressure cooker from the heat.
The pressure cooker lid should not be removed until the pressure gauge reads zero. This can take anywhere from 15 minutes to an hour. The vials can then be removed and placed on a towel to cool before storage. All jars that have not been sealed properly should be consumed immediately or stored in a refrigerator and consumed within a few days.