Can You Freeze Canned Stewed Tomatoes?

If you have a garden, you have probably noticed that tomatoes seem to all ripen at once. Even a single plant can yield more tomatoes than you can eat fresh. Stewing the tomatoes and canning them is one way to put them away for use during the winter. Sometimes, however, you may need to freeze a can or jar of stewed tomatoes. Doing so is a good way of preserving their freshness.

Canning vs. Freezing

When you freeze food, you preserve it by starving bacteria of the water they need to multiply. When water freezes, it's no longer available to the bacteria, which need water to reproduce. Bacteria either die or go dormant. Either way, they can't break down the food and cause it to spoil. Canning, on the other hand, uses high heat to kill food-borne bacteria. Typical canning procedures call for the can to be sealed when it is hot, so no new bacteria can enter the can and cause spoilage. In other words, even if you freeze stewed tomatoes in canning jars using canning lids, they are not "canned" because canning and freezing use two different mechanisms to preserve food.

Freezing Canned Food

Sometimes when you can home-stewed tomatoes, the jar lid doesn't seal correctly. Without this airtight seal, the food inside is unprotected from bacteria. If a jar doesn't seal you have three options. One is to go through the canning procedure again to seal the jar. You can only do this within 24 hours of the initial canning procedure. The second is to treat the food as fresh and eat it within a few days. The third is to freeze the contents. You can freeze tomatoes in the canning jar, but you will have to remove some of the contents to allow for a 1 1/2-inch headspace for expansion. You must freeze the tomatoes within 24 hours of when the lid seal breaks or refuses to seal. If you aren't sure when the seal broke, treat the tomatoes as spoiled and throw them out. Don't freeze tomatoes in sealed cans or jars. doing so is not only unnecessary; it's dangerous because expansion can damage the container.

Freezing Excess Tomatoes

Sometimes you may find that you have more canned stewed tomatoes than you can use in a single use. This can be true if you home-can tomatoes in quart jars or larger or if you buy commercially canned stewed tomatoes in large, restaurant-sized cans. You can freeze the excess once the can is open. For best results, take the stewed tomatoes directly from can and put them in a clean, freezer-safe container. Freeze them immediately.

Handling Frozen Tomatoes

Once frozen, the tomatoes should be treated as frozen leftover tomatoes, not as canned tomatoes. According to the USDA Food Safety and Inspection Service, canned tomatoes can kept for up to 18 months. Frozen tomatoes should be not be kept more than eight months. Treat the frozen tomatoes as leftovers. When you use them, thaw them in the refrigerator or cook them quickly from a frozen state. They must reach a temperature of at least 165 degrees to kill any bacteria that may have accumulated when the seal broke.