What is the best way to check and see if a jar is completely air tight before storing any food in it?
Canning jars generally have metal lids. "Airtight" for this purpose is just airtight as much as possible. It doesn't mean the jar has to have a vacuum seal like you'd need if you were actually canning something. If you are concerned about the jar, make sure it's dry on the outside, put some water in it, put the lid on, and then turn it over and see if your hand gets wet. If not, then it's airtight enough for purposes of storing dried fruit.
