Making tomato paste at home is a simple way to preserve fresh tomatoes and enjoy a richer, more natural flavour than most store-bought versions. Homemade paste contains no artificial preservatives, and you can control the salt, oil, and cooking method.
With the right process, you can make a large batch during tomato season and store it for months. This guide explains how to prepare, cook, and preserve tomato paste using basic kitchen tools.
Ingredients and equipment
Ingredients
- Fresh tomatoes (Roma or plum tomatoes work best because they have less water and more flesh).
- Salt (optional, to taste).
- Olive oil or any cooking oil (optional, for preservation).
- Citric acid or bottled lemon juice (optional, if you plan to can the paste for long-term storage).
You do not need garlic, onions, or spices for basic tomato paste. Those can be added later when you cook your meals.
Equipment
- Large pot or saucepan.
- Food mill, blender, or sieve.
- Wooden spoon or spatula.
- Baking trays (if using the oven method).
- Clean glass jars or freezer-safe containers.
- Ice cube trays (optional, for freezing small portions).
- Sterilised lids and jars (if canning).
Step-by-step method
Step 1: Choose and wash the tomatoes
Select ripe, firm tomatoes without bruises or soft spots. Wash them thoroughly under clean water to remove dirt and debris.
Remove the stems and cut out any damaged areas. You do not need to peel the tomatoes at this stage because the skins will be removed later.
Step 2: Cook the tomatoes
Place the tomatoes in a large pot. You can cut them into halves or quarters to help them soften faster.
Add a small amount of water if needed to prevent burning at the beginning. Cover the pot and cook over medium heat until the tomatoes become soft and release their juices. This usually takes 20 to 30 minutes.
Stir occasionally to prevent sticking. The tomatoes are ready when they break down easily and look pulpy.
Step 3: Remove skins and seeds
Allow the cooked tomatoes to cool slightly. Then pass them through a food mill, blender, or fine sieve to remove the skins and seeds.
If using a blender, blend the tomatoes briefly and then strain the mixture through a sieve. Press the pulp with a spoon to extract as much liquid as possible.
You should be left with a smooth tomato purée without large pieces of skin or seeds.
Step 4: Reduce the purée to a paste
Return the strained purée to the pot. Add salt if desired. Cook over low to medium heat, stirring frequently to prevent burning.
The goal is to evaporate most of the water until the mixture becomes thick and concentrated. This process can take 1 to 3 hours depending on the quantity and water content of the tomatoes.
Signs that the paste is ready:
- It becomes much thicker and darker in colour.
- It does not separate into liquid when you stir it.
- It leaves a clear trail on the bottom of the pot when you drag a spoon through it.
- The volume reduces significantly, often to about one-quarter of the original purée.
You can also use the oven method if you prefer. Spread the purée on baking trays and bake at a low temperature (around 140°C to 170°C) for 2 to 4 hours, stirring every 30 minutes until thick.
Step 5: Cool the paste
Once the paste reaches the desired consistency, remove it from heat and allow it to cool completely. Do not cover it while it is still hot because trapped steam can encourage mould growth.
Stir occasionally as it cools to prevent a skin from forming on top.
How to preserve homemade tomato paste
Tomato paste can spoil quickly if not stored properly. Choose a preservation method that matches how soon you plan to use it.
Method 1: Refrigeration with oil layer
Transfer the cooled paste into clean, dry glass jars. Smooth the surface and pour a thin layer of olive oil on top. The oil creates a barrier that reduces exposure to air and helps prevent mould.
Seal the jar tightly and store it in the refrigerator. Always use a clean spoon when removing paste to avoid contamination.
This method can keep the paste fresh for 3 to 4 weeks. If you notice any unusual smell, colour change, or mould, discard the entire jar.
Method 2: Freezing in small portions
Freezing is one of the most convenient methods for long-term storage.
Spoon the cooled paste into ice cube trays. Freeze until solid, then transfer the frozen cubes into a sealed freezer bag or container. Label with the date.
Each cube can be used as a single portion when cooking sauces, soups, or stews. Frozen tomato paste can last for 6 to 9 months.
If you do not have ice cube trays, you can spread small spoonfuls of paste on a tray lined with parchment paper. Freeze until solid, then pack the frozen portions into a bag.
Method 3: Canning for long-term storage
Canning allows you to store tomato paste at room temperature for an extended period, but it requires careful preparation to ensure safety.
Sterilise your jars and lids by boiling them in water for at least 10 minutes. Keep them hot until you are ready to fill them.
Reheat the tomato paste until it is hot but not boiling. Add a small amount of bottled lemon juice or citric acid to each jar to maintain safe acidity. This step is important for preventing bacterial growth.
Fill the jars with hot paste, leaving about 2 centimetres of space at the top. Wipe the rims clean, place the lids on, and tighten the bands.
Process the jars in a boiling water bath for about 30 to 45 minutes, depending on your altitude and jar size. Follow trusted canning guidelines for exact times.
After processing, remove the jars and allow them to cool. You should hear a popping sound as the lids seal. Check that the lids are firmly sealed before storing. Properly canned tomato paste can last for 12 months or more in a cool, dark place.
Once opened, transfer the paste to the refrigerator and use within a few weeks.
Tips for best results
- Use ripe, firm tomatoes for better flavour and colour.
- Remove as much water as possible during cooking to achieve a thick paste.
- Stir frequently to prevent burning, especially near the end.
- Do not add too much salt if you plan to can or freeze the paste, as this can affect preservation.
- Always use clean, dry utensils when handling the paste.
- Label your containers with the date so you know when they were made.
- If you notice any off smell, colour change, or mould, discard the paste immediately.
How to use homemade tomato paste
Homemade tomato paste can be used in many dishes, including:
- Stews and soups.
- Rice and pasta sauces.
- Curries and marinades.
- Casseroles and baked dishes.
- Pizza sauce.
- Bean and vegetable dishes.
Because it is concentrated, you only need a small amount to add depth and flavour to your meals.
Making and preserving homemade tomato paste is a practical way to reduce waste, save money, and enjoy better flavour. With fresh tomatoes, simple cooking, and proper storage, you can create a versatile ingredient that lasts for months.
Choose a preservation method that fits your needs: refrigeration for short-term use, freezing for convenience, or canning for long-term storage. With careful preparation and clean handling, your homemade tomato paste can become a staple in your kitchen throughout the year.