Jar flipping is an age-old canning method used to extend the shelf life of foods, including jams and jellies. The process is relatively simple: once you have filled the jar with hot jam and closed the lid tightly, turn it upside down while the jam cools.
Turn a jar of homemade jam upside down to preserve it better?
Once the pot is turned upside down, the heat of the contents produces water vapor which condenses inside. As it cools, this water vapor turns into droplets that fill the air space above the jam. By turning the pot upside down, these water droplets come into contact with the lid, creating an additional seal. This air gap prevents the proliferation of microorganisms, such as mold or yeast, which need oxygen to grow. By turning the jar upside down, you will extend the shelf life of your jam.
Do you always have to turn over all the jars of homemade jam?
Jam jar turning is a commonly supported technique in food safety and cooking. We therefore find this technique in canning guides, but also in cookbooks published by great chefs. Thus, in his work My secrets & tricks: 200 recipes for jams, jellies, compotes and chutneys in 15 minutes, Francis Miot, French confectioner, recommends turning the jars with screw lids upside down until the jam has completely cooled. However, turning the pots is not suitable for all preparations. Some recipes may therefore require other canning methods to ensure long-term stability.
Read also :
⋙ How to make a perfect jam? Advice from the jam maker of the year 2022, Jean-Christophe Michelet
⋙ 5 seasonal recipes to cook delicious homemade jams
⋙ What is the French’s favorite jam? (+ the homemade recipe to enjoy it)