Canning Tomatoes

Traditionally, canning tomatoes has usually been done by using the hot water bath canner method. Recently, however, more people are finding that canning tomatoes in a pressure canner will result in higher quality and give you a more nutritious product.Pressure canning is also required for many canned tomato combination products because the pH value is above 4.6 which is a low acidic food. Tomatoes themselves fall close to the low acid level, just slightly above 4.6 and when mixed with meat for sauces or with vegetables like peppers or zucchini, which are a low acidic food it raises the pH value above 4.6 and must be processed by pressure canning to insure food safety. Foods that have a pH value of 4.6, or lower, may be processed in a boiling water bath canner.When canning tomatoes by themselves, it is recommended that acid should be added to lower the pH level. This can be done by adding 1 tablespoon of lemon juice or 1/4 teaspoon citric acid per pint of product. For quarts, add 2 tablespoons of lemon juice or 1/2 teaspoon citric acid. This may be done by adding directly to jars before filling.

To RecipesWhole Tomatoes Crushed Without Liquid With ZucchiniStewed Tomatoes Seasoned Mexican Chile Pepper SauceChile Salsa Chili Sauce Spaghetti Sauce

Jars and LidsLidsPlace jar lids in a small sauce pan filled with water and boil gently for 10 minutes before using. Do this before you need to place them on jars.

Leave in hot water and remove as needed. Sometimes recipes will say that it is not necessary to sterilize jars if they are to be packed with hot food. However, to be safe it is always a good idea. For preparing jars, wash them in hot soapy water and rinse well.

Place in a large pot of water or water bath canner, and boil gently for 10 minutes. Leave in hot water until needed. Then remove a few jars at a time and place upside down to drain. They are ready to use in less than a minute.

Processing Methods Boiling Water Bath Canner Fill the kettle with the appropriate amount of hot water and begin heating it on the range. The water bath canner requires 1 to 2 inches of water above the tops of jars. This can be difficult to determine before the filled jars are in place but after a batch or two you will learn how much water you you have to add. It is always a good idea to have an extra small pot of water heating just in case.

Place jars on rack immediately after packing.

Lower filled rack into canner. Jars should be covered by 1 to 2 inches of water. Add additional boiling water if needed. If you add more water, pour between jars and not directly on them (this is where the extra pot of heated water comes in handy).

Cover pot with lid. When the water comes to a rolling boil, start to count the processing time. Reduce heat slightly and boil gently for the time recommended for the food being processed.

When the cooking time is up, remove jars at once and place on a rack or on towels away from heat and away from any draft. Keep jars separated to allow for air space.

After jars have cooled, test for seal. To do this press down on the center of the lid. The lid should be con-caved and not move when pressed. Another method is to tap the lid with the bottom of a teaspoon. If the jar is sealed correctly, it will make a high-pitched sound. If it makes a dull sound it means the lid is not sealed or possibly that food is in contact with the underside of the lid.When completely cool, the screw bands may be removed if desired but not necessary.

Be sure to label canned jars with content and processing date. Store jars in a cool dark, dry place. If there is a possibility of freezing temperatures during storage, cover with a blanket or heavy cloth. Jars may also be placed in a box and stuffed with newspaper.

Pressure CannerFollow manufactures instructions for opening and closing the pressure canner.

Have 2 to 3 inches of hot water in pressure canner and stand the jars on the rack insert so they are not touching each other or the sides of the pot.

Fasten lid and turn on heat. Steam, mixed with air, will start to flow from the vent and then This is about 8 to 10 minutes after the first sign of steam. As the air is driven out from the canner the steam will change from a white vapor or cloud to nearly invisible.

Start processing time when pressure has been reached or when weighted gauge begins to rock. It is then time to close the the pet-cock or regulator. Maintain a steady pressure during processing.

When processing time is up, remove the canner from heat and let the pressure return to zero without assistance. Standard heavy-walled canners take about 30 minutes when loaded with pints and about 45 minutes when loaded with quarts. Do not attempt to cool pot with cold water. This can cause liquid to escape from jars and keep lids from properly sealing. It can also cause pot warpage.

After pressure reaches zero, wait 2 minutes longer and then slowly open or remove the pet-cock or regulator. Unfasten cover and tilt the far side up so any steam remaining will escape away from you. Using a jar lifter, remove each jar and place on a dry, non-metallic surface or towel. Leave space between jars for air circulation.

After jars have cooled, test for seal and the screw bands may be removed if desired. Be sure to label canned jars with content and processing date. Store jars in a cool dark, dry place.


Processing TimesProcessing, or canning times, are usually for an altitude of 0 to 1000 feet. If you are canning at a higher altitude, the times will need to be increased. This is because water has a lower boiling point at higher altitudes. Because of the lower boiling temperature the processing time is increased to insure that the harmful bacteria is destroyed.Water Bath CannerFor the Boiling Water Bath method, process an additional minute for each 1000 feet in elevation. (i.e.) 5000 feet=5 additional minutes of processing time.Dial Gauge Pressure CannerFor pressure canning at higher altitudes the time remains the same but the pressure needs to be increased.2000 to 4000 feet, 12 pounds pressure.4000 to 6000 feet, 13 pounds pressure.6000 to 8000 feet, 14 pounds pressure.