This doesn't specify that it's "refrigerator jam" and must be kept refrigerated, not just "until it thickens," because it is not processed in a boiling water bath and in sterile jars. Also, it may be low calorie, but it is not sugar-free, since there is naturally occuring sugar in apple juice.

Hi Susan,

This recipe only makes 1-1/2 cups and says it should be refrigerated. Since this isn't enough for a canning project (it would only make a 12 oz. jar), just keep it in the refrigerator.

Sugar-free usually means "no sugar added". Sugar has not been added to most apple juice. Naturally occurring sugar in fruits is normally referred to as "fructose".

-- CM