This process seals the jars, protecting the jam from mold or bacteria. Here’s what you need to know (and what you need to have) to get started. The 15 Best Canning Tools, According to an Expert ...

Jam is nothing more than a balance of pectin, sugar, and acid. No wonder Marie Curie loved making it so much. All preserved fruit—whether jam, jelly, or marmalade—depends on the same chemistry.