Canning previously frozen tomatoes is not safe in all situations
When your vines are producing tomatoes like crazy (or the farmers markets have end-of-season bargains that are simply too good to pass up), keeping up with canning them before the fruits become overripe or spoil can be a challenge. Freezing tomatoes – whether whole, sliced, or puréed – is a great way to preserve them for cooking with later. But is it possible to freeze tomatoes now and then can them later? That depends.
Tomato canning recipes are based on using fresh tomatoes. Because tomatoes turn mushy after freezing, they can pack too densely into jars, leading to problems with heat penetration (and thus potential spoilage or safety issues). Quality can also be a concern. This makes previously frozen tomatoes inappropriate for canning tomato products such as whole or quartered tomatoes or salsa.
Recipes best suited for canning using previously frozen tomatoes include well-cooked products such as juices and sauces, or perhaps stewed or crushed tomatoes. If you choose to can previously frozen tomatoes, once thawed be sure to use the entire tomato, including all of the thawed juices.
Exceptions to canning previously frozen tomatoes include those that have frozen on the vine. These tomatoes are lower in acidity and are unsafe for canning. Never can tomatoes that have frozen on the vine. Additionally, do not can overripe tomatoes, including those that have been previously frozen.
For further information on canning visit the National Center for Home Food Preservation (NCHFP) at nchfp.uga.edu or contact your local Cooperative Extension office.
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Brought to you by the UCCE Master Food Preservers of El Dorado County
Last updated: July 2025