Good Morning @vcelier. Even as a child, I could experience with my grandparents as in the summer fruits and vegetables were cooked. This gave you the possibility to use fruit and vegetables from the garden in the winter for cooking. And today, where everything can be bought at any time of the year, the preservation of food has been somewhat in the background. However, my wife and I still use this method to continue using our garden. For example, sour cucumbers and sour beans, besides jam always enjoy. Thanks to your informative contribution, I now know who invented this method. Thank you for sharing my friend.