Water-Bath Crushed Tomatoes

From the garden

• 12 lb ripe tomatoes, washed · paste types give a thicker pack; any ripe, unblemished tomato works

From the pantry

• 2 tsp citric acid · 1/2 teaspoon per quart jar, or swap in 2 tablespoons bottled lemon juice per quart
• 4 tsp canning salt (optional) · 1 teaspoon per quart, for flavor only; safe to omit

1. Fill a boiling-water canner and bring it to a simmer. Wash 4 quart jars and keep them hot in simmering water until filling time; prepare the lids according to the manufacturer's directions.
2. Peel the tomatoes: dip them in boiling water 30–60 seconds until the skins split, plunge into ice water, then slip off the skins. Cut out the cores, trim any blemishes, and quarter.
3. Put a sixth of the quarters in a large pot and crush them with a potato masher as they heat, so they release juice. Bring to a boil, then gradually add the remaining quarters, stirring constantly. The later additions don't need crushing. Boil gently 5 minutes.
4. Add 1/2 teaspoon citric acid (or 2 tablespoons bottled lemon juice) and 1 teaspoon salt, if using, to each hot jar. Ladle in the hot tomatoes, leaving 1/2 inch of headspace. Run a thin spatula around the inside to free air bubbles, wipe the rims clean, and screw on the lids to fingertip-tight.
5. Lower the jars into the canner so boiling water covers them by 1–2 inches. Process quarts 45 minutes (pints 35) at a steady boil. Altitude adjustment: add 5 minutes at 1,001–3,000 feet, 10 minutes at 3,001–6,000 feet, 15 minutes above 6,000 feet.
6. Lift the jars out and cool undisturbed 12–24 hours. Check the seals: lids should be concave and not flex when pressed. Remove the bands, label and date, and refrigerate any jar that didn't seal.