Canning a Big Tomato Harvest: Passata, Sugo & Tomato Sauce

Canning a Big Tomato Harvest

High summer always brings the same problem: too many tomatoes at once. The solution: canning. One busy Saturday afternoon yields enough of a stock to last the whole year.

Passata – the Most Versatile Tomato Base

Passata is puréed, strained tomato juice – the foundation of all tomato sauces.

Ingredients (makes about 6 liters):

• 8–10 kg ripe beefsteak or vine tomatoes
• 2 tsp salt
• 1 tbsp lemon juice or ¼ tsp citric acid per litre of passata
• Optional: fresh basil

Steps:

1. Wash the tomatoes, remove the stem end, and roughly dice.
2. Cook soft in a large pot without water (20–30 min.).
3. Push through a food mill or fine sieve – the skins and seeds stay behind.
4. Bring back to a boil, season with salt.
5. Acidify: stir in 1 tbsp lemon juice or ¼ tsp citric acid per litre of passata. This is not a matter of taste but the safety step – without added acid tomatoes sit right at the pH threshold and are not considered safely canned (see "Safe Canning: Avoiding Botulism").
6. Fill boiling hot into sterilized bottles/jars, seal immediately.
7. Process in a water bath 30 min. at 100 °C.

Shelf life: 1–2 years, stored dark and cool.

Sugo – Ready-Made Tomato Sauce

Sugo is more richly seasoned than passata – ready to use straight as a pasta sauce.

In addition to the passata base:

• 4 garlic cloves (sautéed in olive oil)
• 2 onions (diced, cooked until translucent)
• 1 bunch fresh basil
• 2 tbsp olive oil, salt, pepper, a pinch of sugar
• Optional: chili, oregano, rosemary

Add everything to the finished passata, simmer 20 min., adjust seasoning, acidify, and can it just like the passata. Onion, garlic and oil push the pH up further – so the added acid matters here even more.

Oven-Dried Tomatoes

For an intense flavor all winter long:

1. Halve or quarter the tomatoes, remove the seeds
2. Place on a baking sheet, cut side up
3. Dry at 90–100 °C fan/convection for 4–6 hours
4. Store dry and airtight – that way they keep right through the winter
5. If you would rather preserve them in olive oil (with garlic and herbs): keep the jar in the fridge only and use it up within a few weeks. Oil excludes oxygen, and the BfR advises against storing vegetables and garlic in oil at room temperature – more on this in "Safe Canning: Avoiding Botulism"

Frozen Tomato Cubes

The fastest method – no cooking required:

• Peel the tomatoes (briefly in boiling water, then ice water), dice
• Freeze in portioned bags → add straight to sauces, soups, and stews

Yield & Planning

• 1 kg of tomatoes yields about 600–700 ml of passata
• For a year's supply (family of 4): can 15–20 kg of tomatoes
• Good varieties for canning: San Marzano, Ochsenherz (oxheart), Moneymaker