Canning Tomatoes
Marilyn Herman
Tomatoes must be canned carefully to avoid spoilage and food poisoning. Some tomato varieties, even high-acid varieties produce lower-acid fruits under some conditions. Therefore, always add bottled lemon juice or citric acid to avoid the risk of botulism.
- Control spoilage by heat processing filled jars in a boiling water canner or a pressure canner. Researchers at Pennsylvania State University have recalculated processing times. They differ from recommendations prior to 1990.
- Select only disease-free, vine-ripened firm tomatoes. Do not can overripe, damaged or frosted tomatoes, or ones from dead vines. They're lower in acid. Freeze them.
- Pretreat new lids in a saucepan of simmering water, or follow manufacturer's instructions.
YOU CAN USE THREE PACKING METHODS:
Crushed tomatoes by hot pack method:
- Peel, remove cores and quarter them.
- Heat rapidly in a large kettle and simmer gently for 5 minutes. Crush with wooden spoon.
- Add two tablespoons bottled lemon juice to each clean quart canning jar, then fill with hot tomatoes.
- Add one teaspoon canning salt if desired.
- Seal with two-piece canning lids; process quarts 50 minutes in a boiling water bath canner.
- If you use a dial gauge pressure canner, process for 20 minutes at 6 pounds pressure, or 15 minutes at 11 pounds pressure.
- With a weighted gauge canner, process 20 minutes at 10 pounds pressure, or 15 minutes at 15 pounds pressure.
Whole or halved raw tomatoes packed in water:
- Add two tablespoons bottled lemon juice to each clean quart and fill with raw whole or halved tomatoes.
- Cover tomatoes in jar with hot water, and wipe off jar lip with damp paper towel.
- Adjust pretreated lids and screw ring onto jar.
- Process quarts 50 minutes in a boiling water bath.
- If you use a dial-gauge pressure canner, process for 15 minutes at 6 pounds pressure or 10 minutes at 11 pounds pressure.
- With weighted gauge canner, process 15 minutes at 10 pounds pressure or 10 minutes at 15 pounds pressure.
Raw whole or halved tomatoes packed in juice:
(Tomatoes packed in juice need a much longer processing time to prevent spoilage.)
- To each quart add two tablespoons lemon juice and one teaspoon salt.
- Fill with peeled raw tomatoes.
- Press to make enough juice to cover, or add previously strained hot juice.
- Wipe off jar lip with damp paper towel.
- Adjust pretreated lids and screw rings onto jars.
- Process for 90 minutes in boiling water bath canner.
- In a dial gauge canner, process 40 minutes at 6 pounds pressure, or 25 minutes at 11 pounds.
- In a weighted gauge canner, process 40 minutes at 10 pounds pressure, or 25 minutes at 15 pounds pressure.
