Canning Tomato Sauce: Summer in a Jar
A shelf lined with jars of homemade tomato sauce is one of the most satisfying sights for any home grower. The process is straightforward, the results are delicious, and one big batch can supply your kitchen for months.
Choosing Tomatoes
Paste tomatoes (Roma, San Marzano, Amish Paste) are ideal — they have more flesh, less juice, and fewer seeds than slicing tomatoes. You need roughly 20 pounds of tomatoes for 7 quarts of sauce. Use only ripe, unblemished fruit.
Basic Tomato Sauce Recipe
- 20 pounds paste tomatoes, cored and quartered
- 2 large onions, diced
- 6 garlic cloves, minced
- 2 tablespoons olive oil
- Fresh basil, oregano, and thyme to taste
- 2 tablespoons bottled lemon juice per quart jar (for safe acidity)
- Salt to taste
Preparation
Blanch tomatoes for 60 seconds, then plunge into ice water. The skins slip right off. Core and quarter. Cook in a large pot until soft, then run through a food mill or blend. Simmer with sauteed onions, garlic, and herbs until thickened — this takes 1-3 hours depending on desired consistency.
Safe Canning Process
Tomato sauce must be processed in a boiling water bath canner. Add 2 tablespoons of bottled lemon juice to each quart jar — this is not optional; it ensures safe acidity. Fill hot jars leaving 1/2-inch headspace. Wipe rims, apply lids, and process quarts for 35 minutes (pints for 30 minutes) at a rolling boil.
Storage
Check seals after 24 hours — the lid should not flex when pressed. Label with date and contents. Store in a cool, dark place. Properly canned tomato sauce keeps for 12-18 months. Any jars that did not seal should be refrigerated and used within 2 weeks.
Log your canning batches in Seedtojar — track quantities, recipes, and use-by dates so nothing goes to waste.