Home-Canned Tomatoes
Safely preserve the bounty of summer with this essential recipe for home-canned tomatoes, ensuring a delicious and versatile ingredient for your pantry all year round. The addition of citric acid is a critical safety step, lowering the pH to prevent spoilage and bacterial growth.
For 16 servings
Wash tomatoes thoroughly under cool running water. Score a small 'X' on the bottom of each tomato. Bring a large pot of water to a rolling boil. Prepare a large bowl of ice water.
Blanch tomatoes in boiling water for 30-60 seconds, or until skins begin to crack. Immediately transfer them to the ice bath to stop cooking. Once cool enough to handle, peel the skins, remove the cores, and chop or crush the tomatoes as desired (whole, halved, or diced).
Sterilize your canning jars, lids, and bands according to manufacturer instructions. Keep jars hot in a pot of simmering water or a warm oven until ready to fill. This prevents thermal shock when adding hot tomatoes.
For each hot quart jar, add 1/2 teaspoon of citric acid (and 1 teaspoon of canning salt, if using) to the bottom. Tightly pack the prepared tomatoes into the jars, pressing down to remove air bubbles and release juices. If needed, add boiling water or tomato juice to cover the tomatoes, leaving 1/2-inch headspace from the rim.
Remove any trapped air bubbles by sliding a non-metallic utensil (like a plastic knife or chopstick) around the inside of the jar. Wipe the jar rims clean with a damp cloth to ensure a proper seal. Center a clean, hot lid on each jar and screw on the band finger-tight.
Place the filled jars onto the rack in your water bath canner, ensuring they are not touching each other. Add hot water to the canner until the water level is at least 1 inch above the jar tops. Cover the canner and bring the water to a rolling boil.
Once boiling, process quart jars for 45 minutes (for altitudes 0-1,000 feet). Adjust processing time for higher altitudes (e.g., 50 minutes for 1,001-3,000 ft; 55 minutes for 3,001-6,000 ft; 60 minutes for 6,001-8,000 ft).
After processing, turn off the heat and carefully remove the canner lid. Let the jars sit in the hot water for 5 minutes before carefully lifting them out with a jar lifter. Place jars on a wire rack or towel-lined surface, ensuring they are not touching, and allow them to cool undisturbed for 12-24 hours.
After cooling, check seals by pressing the center of each lid; it should be concave and not flex. If a lid does not seal, refrigerate and use within a week, or reprocess with a new lid. Remove bands, wipe jars clean, label with contents and date, and store in a cool, dark place for up to 18 months.
What to keep in mind.
4 tips from the recipe — small details that make a real difference to the final dish.
- 1Always use a reliable, up-to-date canning guide (like those from USDA or university extensions) for precise processing times based on your altitude and jar size.
- 2Ensure proper headspace (1/2 inch for tomatoes) is maintained to allow for expansion during processing and to create a strong vacuum seal.
- 3Use only canning-specific salt (without anti-caking agents) if adding salt, as regular table salt can make the canning liquid cloudy.
- 4For best results, choose firm, ripe paste tomatoes (like Roma or San Marzano) as they have less water content and more flesh, resulting in a thicker, richer product.
Adapt it for your goals.
Crushed Tomatoes
After peeling and coring, simply crush the tomatoes by hand or with a potato masher before packing into jars. This yields a rustic, chunky sauce base.
Diced TomatoesDiced Tomatoes
For a more uniform texture, dice the peeled and cored tomatoes into small pieces before packing. This is great for recipes where you want distinct tomato chunks.
Herbed TomatoesHerbed Tomatoes
Add 1/2 teaspoon of dried Italian seasoning, a fresh basil leaf, or a sprig of fresh oregano to each jar along with the citric acid for infused flavor.
Why this is on our healthy list.
Rich in Lycopene
Tomatoes are an excellent source of lycopene, a powerful antioxidant that may help protect against certain chronic diseases, and its bioavailability is enhanced by cooking.
Vitamin C Boost
These home-canned tomatoes provide a good amount of Vitamin C, essential for immune function, skin health, and acting as an antioxidant.
No Unwanted Additives
Canning your own tomatoes allows you to control the ingredients, avoiding artificial preservatives, excessive sodium, or added sugars often found in commercial products.
Frequently asked questions
Citric acid or bottled lemon juice is crucial because tomatoes can vary in acidity. Adding it ensures the pH is consistently below 4.6, which is necessary to prevent the growth of Clostridium botulinum, a bacterium that produces a deadly toxin in low-acid, oxygen-free environments.
