How Long Can Cooked Jello Last In The Refrigerator?

If it's real jelly and not dietetic or something believe it or not but
it has natural preservatives. Mostly sugar. You see the sugar is at
such a high concentration that the water is not accessible to bacteria
and usually not yeast. About the only thing that can grow on jelly is
mold and if you don't see any mold the jelly is still good. Keeping it
in the refer helps a lot since mold only grows slowly in cold temps