Earlier quoted context omitted.
Jam is generally shelf stable. The sugar is really good at killing bacteria (deprives them of water iirc).
Huh! If "shelf-stable" means "refrigerate after opening" then yeah. But I'm confused whether it's "refrigerate optional" like ketchup https://www.marthastewart.com/8269604/should-you-refrigerate... > You can technically store opened jams and jellies at room temperature—but only in a cool, dark place and for about a week after opening, says Lee. Here's why: Jams and jellies have high sugar and acid levels, which prote…
Same thing with jars of Mayonnaise - that one gets you strange looks.