Canning tomato products - safety guidelines (2024)

FAQs

Canning tomato products - safety guidelines? ›

Add acid to all tomatoes before processing. A high acid level (pH of 4.6 or less) prevents the growth of Clostridium botulinum bacteria which causes botulism. Because many factors impact the acidity level of tomatoes, USDA recommends adding acid to all home-canned tomatoes and tomato products.

The USDA and University-based researchers have determined that to ensure a safe acid level for boiling water canning of whole, crushed, or juiced tomatoes, add 2 tablespoons of bottled lemon juice or ½ teaspoon of citric acid per quart of tomatoes.

Choose cans with the fewest ingredients: We prefer tomatoes packed with salt, but avoid sugar, garlic, or any preservatives other than calcium chloride and citric acid.

Recommended Methods

Boiling water or pressure canning are both accepted methods for canning tomatoes. Other methods such as oven canning and open-kettle canning can be hazardous and should not be used. All steps in preparing and cooking the foods need to be followed for the processing time as recommended by the USDA.

Some growing conditions may cause the tomatoes to be unsafe to can even when the tomatoes look fine. Tomatoes with blight and those from dead or frost-killed vines may be lower in acidity and are more likely to carry bacteria. Do not can using the open kettle method.

A high acid level (pH of 4.6 or less) prevents the growth of Clostridium botulinum bacteria which causes botulism. Because many factors impact the acidity level of tomatoes, USDA recommends adding acid to all home-canned tomatoes and tomato products. Treat heirloom tomato varieties the same as any other tomato.

If it smells off or has an altered color, throw it away. Be prudent. A really good looking can of tomatoes, not swollen, leaking, dented, or rusted, that is a few months past its date, is more than likely okay. But if the can is years past its date, toss it out and purchase a new one.

The short answer to the question is “Yes, to ensure safety, acid in the form of lemon juice, citric acid or vinegar must be added to tomatoes that will be processed by a pressure canning option”.

And you don't need a water bath canner either; any pot large enough to cover the jars with at least one inch of water works. Whichever canning method you choose, canning tomatoes always requires acidification to make them safe.

Yes, and it takes extra time. But it is important and time well spent for safely canned tomatoes. According to the National Center for Home Food Preservation, “Most bacteria, yeasts, and molds are difficult to remove from food surfaces.

Can you add onions to tomatoes when canning? ›

Measure ingredients accurately—don't use the extra onion to finish off what is cut up. Add no more than three cups in any combination of finely chopped celery, onions, carrots, and pepper for each 22 pounds (the amount for seven quarts) of tomatoes when making tomato-vegetable juice blends.

Tomatoes and tomato products have traditionally been canned in a boiling water bath (212 °F). However, recent research shows that for some products, pressure canning will result in a high-quality and more nutritious product. Directions for canning a variety of tomato products are given below.

Grades of Canned Tomatoes

U.S. Grade C is the quality of canned tomatoes that meets the applicable requirements of Tables I, II, III, IV, and V of §52.5170, and scores not less than 70 points. Substandard is the quality of canned tomatoes that fails the requirements for U.S. Grade C.

Tomatoes are warm- and sun-loving plants. Full sun for at least 8 hours a day is essential for growing healthy crops. They also need a warm environment; tomato growing temperatures between 71 and 84˚F (22 and 29˚C) will be ideal. Though the crops can endure cool weather, their development will be stunted.

We can only recommend the jars that have the 2 piece lids, like Ball, Kerr, or Leifheit to name the major brands. They are the only type of jars recommended by the USDA. No other jars or lids (including the Tattler lids) are approved by the USDA for canning in the US.