September is a perfect month to devote yourself to summer preserves, and try to enclose in a jar the summer that is about to end. But in addition to being good, it is important to prepare safe preserves to avoid even serious risks to your health.
As already explained in the article dedicated to the importance of sterilizing cans for preserves, the greatest danger is botulinum, a bacterium that produces the most powerful toxin known.
Botulinum toxin is produced only when the bacterium finds fertile ground for its activation and proliferation, and this happens in some conditions:- l
ack of oxygen – low
acidity or salinity- d
Therefore, foods in oil, non-acid vegetables in oil or water, soups and soups that are not properly refrigerated and home-made vacuum foods are to be considered potentially contaminated.
Tips for safe preserves even at home
To minimize the risks, even at home we can produce safe preserves with a few small precautions.
First of all, we need to follow basic personal and cooking hygiene standards, which can be the first source of contamination. Wash your hands well with soap, change towels often and use clean tools avoids most microorganisms.
The choice of ingredients is also important: always prefer seasonal products, because they are richer in nutrients, and organic foods so as to avoid the risk that plants may contain pesticide residues and pesticides. Fruits and vegetables should be washed well under running water in order to eliminate soil and other residues, and it is useful to soak them for a few minutes in water and baking soda for greater cleaning.
For this reason it is even more important to have quality ingredients, and thanks to the service of Cortilia you can choose from a wide selection of fresh and genuine products, grown with love and delivered directly to the house, in a few hours.
Check the jars
Jars, bottles and lids must be properly prepared: read as methods used to sterilize and sanctify cans for preserves.
The jars should never be filled to the brink: it is important to leave an empty space that is called "head space". In the case of jams and jams, the filling should be done hot leaving a head space of one centimeter.
The other preserves such as tomato puree and pickles need further treatment, called pasteurization, which consists of boiling the filled and well-closed jars to create the vacuum. You can do pasteurization by completely immersing the pots in a very high pot, filled with water. The water level must exceed the cap of containers by at least 3-4 centimeters. Put the lid on the pot, bring to the boil and allow to boil continuously, evenly and without interruption.
Before consuming the preserve, check the jars: the metal lids should not have bulges, there must be no bubbles or gas or liquid leakage. If the presence of botulinum toxin often occurs with the bulge of the lid and with a smell of rancid, the opposite is also true. The extreme danger of this bacterium in fact comes from the ability to proliferate while maintaining the sensory characteristics of the product itself.
If in doubt, before the consumption of a preserve you can repress the closed jar (80 degrees C for at least 20/30 minutes) or boil the contents before consuming it, so as to make harmless the possible botulinum toxin.
One of the most popular home preparations is tomato sauce, or past, which is one of those to be considered at risk for the proliferation of the botulinum bacterium. For the preparation of the past it is preferable to use more acidic tomato varieties (with a pH< 4,3).></ 4,3).>
If the tomatoes were not acidic enough, you can intervene by adding lemon juice (15 ml per 500 ml of finished product) or food-based citric acid (1/4 teaspoon per 500 ml of finished product).
Jams and jams
They are sufficiently acidic, thanks to the fruit and sugar used, provided that the amount of sugar is adequate (at least 50% of the weight of the fruit).
After filling the jar with the hot jam, hermetically close the jars and flip them over by placing them on a cold surface, letting them cool to room temperature. When the containers are well cooled, they must be thoroughly inspected to assess the vacuum attainment.
The metal caps or capsules should appear slightly concave (curved inwards of the container) and should not do "click-clack".
Preserves in oil
Carefully select the vegetables, wash them and cut them into pieces. Blanch for a few minutes in a solution of water and vinegar in equal parts. This also applies to ingredients to be used to prepare flavored oils (garlic, chilli, herbs). After the rather short cooking phase, the ingredients should be dried on a cloth and inserted into the containers, taking care to fill all the spaces. In the jar, they must be covered completely with oil.