In 1795, Nicolas Appert discovered canning or sterilisation through heat: a genuine revolution! Because up until his discovery, we kept food thanks to ancestral techniques such as salting, drying, smoking, fermenting or candying in sugar or fat. The canning technique – simple and efficient – has since been used by generation of cooks and in a large scale by specialised companies such as Bonduelle. Healthy and safe as long as you abide by the rules, here is how to proceed to make your own canned vegetables.
Material Preparation
To avoid any contamination or the development of undesirable bacteria, the hygiene rules must be strictly followed from the preparation of glass jars, whether they are hinge- or screw-top glass jars: they must be in a perfect state, not chipped nor cracked. Wash them cautiously with washing-up liquid and a non-abrasive sponge, rinse them thoroughly with warm water then let them dry without wiping them. Boil the rubber or tops. Clean your hands as well as your kitchen counter.
The ingredients
While the vegetable garden is plentiful, make sure only to harvest and can good quality, fresh vegetables, especially not damaged. Do not use frozen vegetables either. Wash them and prepare them (peel, hull, cut...), always respecting strict hygiene rules. Most vegetables are better when pre-cooked for 2 minutes in boiling water then drained. Place them in jars still very hot by filling them up to 2cm of the top, then pour a liquid if required by the recipe.
Closing and sterilising jars
Finally, proceed with sterilisation which is warming the jars at or above 100 °C. Place the rubber slices or tops and close the jars cautiously then proceed to the heat treatment either in an electric steriliser, a large pot or a pressure cooker with a cloth at the bottom to avoid the jars clashing with one another. Bring to boil and respect the duration specified in the recipes which guarantees optimal conservation. Once the water has cooled down, you can take your jars out. Let them cool down and don’t forget to label them: Bonduelle factories follow the same steps on a larger scale of course!