Summer preserves

Each kind of fruit or vegetable has its season, when it is plentiful. What you don’t use now can be useful later. How do you preserve them?

The best time to eat fruit and vegetables is when they are harvested naturally. This is when they are healthiest and most plentiful. However, this is not the only time you can eat them. Tomatoes arrive in summer and autumn but are still used to prepare meals in winter.

In shops you can find out-of-season food products which come from glasshouses and cold stores or are imported from abroad. But the fruit and vegetables that are available in the largest quantities are the season’s produce, whose quality (and price) will be the best.

One of the principles of smart consumption is not to waste any of the resources we have. Preserving is a great way to take advantage of abundant supplies.[1] The preserving industry does this on a large scale, and we can do it ourselves on a small scale at home. Fresh fruit and vegetables that are in season can be bought cheaply if they are purchased in large quantities. This is also the case if they are fairly ripe, as shops cannot sell them so easily.

It is easy to find recipes, as they are part of our traditional culture.

What can be preserved?

To preserve food you have to put it in a medium where microbes cannot develop: very hot, very cold, acid, salty, with no air, etc.

You can preserve fruit, vegetables, meat and fish: each type of food has its own recipe. In this section we explain how to preserve tomatoes and other summer fruit (plums, pears, grapes, peaches, etc.), which all have a certain level of acidity, because they are easy to preserve and are widely used in our cuisine. The recipe is not recommended for strawberries or blackberries because they are more fragile.

If you have small amounts of food which are likely to go off, a quick way to preserve it is to freeze it. If you buy preserves, choose homemade, local, ecological products.

Things to remember

It’s very important to keep your hands clean and use clean utensils. If you need extra-clean containers and lids (e.g. for babies or people with poor immunity), boil them for a few minutes. You’ll save energy if you keep the pots warm while you put food into them.

It is important for the lids to close tightly. They must not be chipped or rusty or have any mould on them. Replace them if necessary (you can buy them separately).

Set aside a whole morning or afternoon to get the fruit and preserve it. It will take you a few hours but the preserve will last for months.

When you open a preserve, check that the lid is not bulging out (a sign of bacteriological activity) and that the contents are not mouldy or spoilt. Once open, it can be kept in the fridge for 3 or 4 days.

How to make your preserves

Tomatoes and other summer fruit can be preserved cooked or raw.

Select the pieces (they should be as ripe as each other), clean them and remove stems and any bruised parts. If you want to peel them (this is advisable if the fruit is not ecological) it is easier if you put them in boiling water for 1 minute and then place them in cold water. You can cut the fruit into slices and remove stones, if any, or leave the fruit intact.

If you are using raw fruit, pack it closely in the container. Optionally add boiling water to 1.5 cm below the lid. A few spoonfuls of sugar (in the case of fruit) or salt (for the tomatoes) can be added to the water.

If you use partly cooked food, put the pieces in water and heat it until it boils (salt or sugar can be added for tomatoes and fruit respectively). You can also stir-fry tomato. Put the food in the jar, ensuring that the pieces are packed closely together (to help them settle put a cloth on the table and bang the jar down on it gently a few times) and fill with liquid to 1.5 cm below the lid. You can add a little oil to tomato to create a protective film.

Put the lids on, do them up tightly and turn the jar over to check that it does not leak. Put the jars in a pressure cooker, using cloths to separate them from each other and the bottom of the pan. Add water to slightly more than halfway up the jars, close the pressure cooker and boil on medium heat. The boiling time varies according to the size of the jars and the type of food. The average time for a jar of tomato sauce or plums is 15 to 20 minutes if they have been cooked previously. A few minutes more will be needed if the fruit is raw.

Turn off the heat, pour off some of the water and remove the jars. Use gloves if necessary. Place them on cloths and allow them to cool to room temperature. They should be kept out of draughts. You can cover them with another cloth to slow down the cooling process. Check that the jars are tightly closed, label them with the date and store them in a cool, dark place.


For the stir-fry: There is no need to heat the jars in the pressure cooker if you fill them with tomato which is freshly fried and very hot. (The jars must also be hot.) Close the lids tightly and turn the jars upside down to cool. You can stir-fry only the flesh of the tomatoes, keeping the juice to drink.

If you use a saucepan instead of a pressure cooker, double the times and add more water (it should cover the jars).

Is it very difficult?

  • You will need to spend a whole morning or afternoon getting the food and making the preserve.
  • If you are not meticulous, you may find it difficult the first time and it could even go wrong but you will learn from experience.
  • The more preserve you make the more useful the energy saving will be.

What do you gain?

  • Preserving makes you aware of seasonal foodstuffs and how you can use them out of season.
  • You take advantage of fruit and vegetables in season when quality is good and they are plentiful and cheap.
  • You keep food in good condition without needing chemical preservatives.
  • You can enjoy cooking, experimenting and eating your own preserves.
  • You will have a readily available, healthy food resource in your pantry.

[1] Agricultural surplus is also exported, used as raw material for the food industry (and others) and sometimes it is dumped.