Kitchen bench with jars of preserved tomatoes and passata

Preserving Tomatoes at Home

Q: How do you preserve tomatoes at home?

Four main methods: passata (cooked, pureed, bottled), oven-roasted sauce (roasted, frozen), sun/dehydrator dried (stored in oil), and freezing whole or chopped.

Q: How many tomatoes do I need for passata?

5 kg of fresh tomatoes produces 2-2.5 litres. For a year's supply, aim for 20-30 kg, about 10 Roma plants.

Q: Can you freeze fresh tomatoes?

Yes. Wash, core, freeze on a tray. Best for cooking as texture changes. Skin slips off easily under warm water after freezing.

Q: How long does homemade passata last?

Properly bottled and water-bath processed: 12-18 months in a cool, dark pantry. Frozen: 12 months.

Turn a summer glut into a year's supply of passata, sauce, dried tomatoes, and frozen bases.

If you grow tomatoes, you know the pattern: nothing for months, then suddenly every plant delivers at once. You're eating them fresh, giving them away, and still can't keep up. This guide covers four reliable methods for preserving your tomato harvest so nothing goes to waste and you have homegrown tomato flavour in the kitchen year-round.

Method 1: Passata (Tomato Puree)

Passata is the foundation. It's smooth, pourable tomato puree that you use as a base for pasta sauce, soup, stews, and pizza. A batch of passata in the pantry replaces every tin of crushed tomatoes you'd buy from the supermarket.

How to make passata

Wash and core tomatoes. No need to peel. Roma varieties are ideal because they have thick flesh and low water content. Any ripe tomato works, but watery varieties produce thinner passata.
Cook down. Roughly chop tomatoes and cook in a large pot over medium heat for 20 to 30 minutes, stirring occasionally, until soft and broken down. No water needed. Tomatoes release plenty of liquid.
Pass through a food mill or sieve. This removes seeds and skin, giving you a smooth puree. A food mill (mouli) is the traditional tool and works fast. A fine sieve and wooden spoon works too.
Bottle hot. Pour hot passata into sterilised glass bottles or jars, leaving 1 cm headspace. Seal immediately. Process in a boiling water bath for 35 to 40 minutes for long-term shelf stability.

Yield: 5 kg of fresh tomatoes produces roughly 2 to 2.5 litres of passata.

Tip: Add a fresh basil leaf to each jar before sealing. It infuses subtly during storage and looks beautiful when you open the jar months later.

Method 2: Oven-Roasted Tomato Sauce

This is the lazy method and it produces the richest, most concentrated sauce. No stirring, no watching the pot.

Halve tomatoes and place cut-side up on lined baking trays. Drizzle with olive oil, scatter with garlic cloves and fresh herbs (basil, oregano, thyme).
Roast at 160 degrees for 2 to 3 hours until tomatoes are collapsed, caramelised, and reduced by half.
Blend. Transfer everything (including the garlic and herbs) to a blender and process until smooth. Season with salt.
Freeze in portions. Pour into labelled zip-lock bags or containers. Freeze flat for easy stacking. Keeps for 12 months.

Method 3: Sun-Dried (or Dehydrator-Dried) Tomatoes

Sun-dried tomatoes concentrate flavour dramatically. They're chewy, intensely savoury, and last months stored in oil.

Halve small tomatoes (Roma, Principe Borghese, or cherry varieties work best). Place cut-side up on wire racks.
Sprinkle with salt. This draws out moisture and acts as a preservative.
Dry in sun for 2 to 4 days (bring racks inside at night). Or use a dehydrator at 60 degrees for 8 to 12 hours. Tomatoes are done when leathery but still slightly pliable.
Store in olive oil. Pack dried tomatoes into clean jars, cover completely with olive oil, and refrigerate. Add garlic, herbs, or chilli flakes for extra flavour. Keeps for 3 to 6 months in the fridge.

Method 4: Freezing

The fastest preservation method. No cooking, no bottling, no special equipment.

Wash and core tomatoes. Leave whole (for small tomatoes) or roughly chop (for large ones).
Freeze on a tray in a single layer until solid. Then transfer to zip-lock bags or containers. Removes air and prevents a frozen block.
Use from frozen. The skin slips off easily under warm water once frozen. Add directly to soups, stews, and sauces. Texture changes during freezing, so frozen tomatoes are best for cooking, not salads.

Keeps for: 12 months in a chest freezer, 6 months in a standard fridge freezer.

Which Method for Which Tomato?

Roma and paste tomatoes: Best for passata and oven-roasted sauce (thick flesh, low water).

Cherry and grape tomatoes: Best for drying and freezing whole.

Large slicers (Grosse Lisse, Beefsteak): Best for oven-roasted sauce and freezing. Too watery for good passata.

Grow Your Own Sauce Tomatoes

Plant Roma, San Marzano, or Principe Borghese in the Planting Season app and get harvest reminders for sauce day.

Open the App →

Frequently Asked Questions

How do you preserve tomatoes at home?

The four main methods are passata (cooked, pureed, and bottled), oven-roasted sauce (roasted and frozen), sun-dried or dehydrator-dried (stored in oil), and freezing whole or chopped. Passata gives the longest shelf life without freezing.

How many tomatoes do I need for passata?

Roughly 5 kg of fresh tomatoes produces 2 to 2.5 litres of passata. For a year's supply (replacing tinned tomatoes), aim for 20 to 30 kg of fresh tomatoes, which is about 10 Roma plants.

Can you freeze fresh tomatoes?

Yes. Wash, core, and freeze on a tray before transferring to bags. Frozen tomatoes are best for cooking (the texture changes). The skin slips off easily under warm water after freezing.

How long does homemade passata last?

Properly bottled and water-bath processed passata keeps for 12 to 18 months in a cool, dark pantry. Once opened, refrigerate and use within a week. Frozen passata keeps for 12 months.