Stored 6 pints of prepared jelly in frig overnight. Can I now place jelly into canning jars and follow water bath processing? Or, do I need to eat it quickly? 🤣
No, from the point of view of food safety, you can't.
"The complete book on small-batch preserving" by Ellie Topp and Margaret Howard has a chapter describing the water bath canning process. It says:
It is important that the jars be processed immediately following the cooking stage.
Canning processes have to be extensively tested to guarantee safety. Deviations mean that your canned goods are no longer safe.
As an aside, your jelly can be frozen, so you don't have to eat it at once. The canning jars work fine for freezing too, but leave more headspace than for canning.