The tomato is a vegetable native to Central America, known already to the Aztecs who attributed to it an aphrodisiac connotation and used its sauce in their dietary habits. It was introduced to Europe in the 16th century under the name "pomo d'amore," which in Italy became "pomo d'oro."
In times when there were neither supermarkets nor industrial production, the population fed itself following the natural seasonality of products and resorted to various ways to preserve some foods throughout the year.
The tomato is one of the most used foods in cooking and ripens during the summer months, during which preserves are prepared to be consumed in the winter. Even today, homemade tomato preserves are far preferable to those of industrial processing because they are definitely more genuine, especially if organic tomatoes are used.
Tomato preserves can be of different types and range from pureed tomatoes to whole or chopped tomatoes.
How to prepare tomato puree
Making tomato puree is not just about following a mere procedure, but it is a true ritual passed down from generation to generation. Here's how to prepare it:
- Gather a certain amount of ripe tomatoes and wash them thoroughly under running water. Typically, from every Kg of tomatoes, you can obtain half a liter (500 ml) of puree. The tomatoes for the sauce can be all of the same variety (for example, San Marzano) or you can also opt for a mix of different tomato varieties (San Marzano, Sorrento tomatoes, datterini, cherry tomatoes, etc.);
- Cut the tomatoes into pieces and place them in a pot, preferably non-stick, removing the stalk, the inner white part, and any damaged areas beforehand. It is important to ensure that there are no spoiled tomatoes or parts, as they can ferment and spoil the entire sauce;
- Add salt, the amount generally varies between 5 and 7 grams per Kg of tomatoes. At this stage, according to personal preference, you can also add fresh basil leaves, the quantity of which varies according to taste;
- Turn on the heat making sure that the flame is as low as possible to prevent the tomatoes from burning and then cover the pot with a lid;
- Stir the tomatoes occasionally with a wooden spoon and increase the heat when water starts to appear at the bottom of the pot;
- Then remove the lid when the tomatoes are completely submerged in water and continue cooking;
- When the tomatoes are well cooked, separate the watery part in a different pan (which can be used in the kitchen for other preparations) and process the tomatoes using a manual or electric food mill choosing the appropriate filter for the desired granularity.
How to store tomato puree
Fresh tomato puree can be stored in the refrigerator for 2 or 3 days and in the freezer for about 4 months.
To store the puree in the pantry, however, it is necessary to pasteurize it to sterilize it from the contamination of dangerous bacteria for our health such as botulism:
- Transfer the tomato sauce into jars (or bottles) that are dry and clean, making sure not to fill up to the rim of the jar and to tighten the lids well;
- Place the jars in a pot of strictly cold water, trying to keep the water level as high as possible;
- Place some crumpled newspaper sheets (or kitchen towels) between the jars to prevent them from breaking during boiling by hitting each other, and in the case of bottles, also cover these ensuring that the cover extends halfway into the water;
- Boil for about an hour on very low heat and upon turning off the heat, let cool completely without moving the pot. It is normal to find the lids swollen after turning off the heat, as it is normal after a few hours to hear small pops coming from the lids;
- Before storing the jars of sauce in the pantry, it is advisable to keep them for a couple of months in a cellar closed, for example, in a plastic bag because it may happen that some of them could ferment and break.