Tomatoes Are Ripe for Home Canning

When canning tomatoes, consumers are advised by the U.S. Department of Agriculture to increase both the acidity and processing time formerly recommended. Today’s fleshier fruit requires these changes to ensure a safe end product.

Begin the canning process by filling a boiling water bath canner half full of water. Place it on the stove top and begin heating. Assemble enough quart-size canning jars to fill the canner rack and wash them with hot, soapy water. Rinse well and place in the canner until needed.

Also wash the canning jar lids and bands and rinse well. Place these closures in a saucepan, add water and bring to a simmer. Remove the pan from the heat, leaving the closures in the hot water.

It’s important to choose firm, red-ripe tomatoes free of blemishes. Wash and drain. Place the tomatoes in a wire basket and lower it into a large sauce pot of boiling water (Step 1). Blanch 30 seconds or until the skins begin to crack. Remove and plunge the tomatoes into cold water.

Core the tomatoes (Step 2), then peel (Step 3) and trim away any green spots. Leave the tomatoes whole or cut in half and place in large sauce pot with water to cover. Bring the water to a boil, then reduce the heat and boil gently for five minutes.

Remove one jar at a time from the canner. Place two tablespoons lemon juice (Step 4) or 1/2 teaspoon citric acid in the jar (sugar may be added to offset the acid taste, if desired).

Using a canning funnel, add hot tomatoes (Step 5), leaving 1/2-inch head space. Ladle hot cooking liquid over tomatoes (Step 6), again leaving the 1/2-inch head space. One teaspoon of canning salt may be added, if desired.

Run a non-metallic spatula between the tomatoes and jar (Step 7) to release any trapped air bubbles. Wipe the jar threads with a clean, damp cloth (Step 8).

Using tongs, remove a lid from the saucepan and place it flat on top, with the sealing compound against the jar. Add the band (Step 9) and screw it down firmly.

Stand the filled jars back in the canner (Step 10). When all the jars are filled, check that there are two inches of water over the jars and at least two more inches of head space in the canner above the water level. Cover the canner and bring the water to a boil.

Begin counting the processing time when the water boils. Process 45 minutes at a gentle, but steady boil.

Remove jars from the canner and place on a wooden or cloth surface, several inches apart and away from drafts. Allow to cool 12 hours, then remove bands and test seals. Properly sealed jars should be stored in a dry, dark, cool place and used within one year.

If jars do not seal properly, reprocess using new seals or refrigerate and use within a few days.