Can you use natural Dutch Jell for thickening fruit pie fillings?

Yes you can no problem. Bake from Frozen for an hour at 350'F.

Better if the crust is all butter! Freeze if and grate it into the flour, add water and cut in with a knife.

Chef Andrew

What sort of pies? Meat? fruit?
What temperature?
These can alter the answer, but if being kept at a temperature at which bacteria cannot grow, (i.e. HOT) then from a health risk point of view, reasonably long, however, the actual pie will deteriorate due to desiccation - the liquid will dry out and the pie go hard and unpleasant.

If being kept at a warm temperature, the risk to health can increase quite quickly, as bacteria start to multiply and cause serious problems. The pie however, will stay apparently edible for longer.

I would not leave anything in a warm place for more than 4 hours and the hot place, whilst not getting full of bugs, a similar time as it will be drying out by then.

I've had the same problem and was able to get rid of the fruit flies using the following method.

First, sprinkle diatomaceous earth on the dirt in the plant pots. Diatomaceous earth is all natural and non-toxic, but it will kill the fruit flies.

Here's a link for killing bugs naturally with diatomaceous earth:
How to Get Rid of Spiders Naturally with Diatomaceous Earth

Next, make a mild soap and water solution, pour it in a spray bottle and spray the plants. Make sure the solution is mild because if it's too strong it will affect the plants.

Here's a link for the homemade insecticide soap recipe:
How to Make Homemade Insecticidal Soap for Plants Today Homeowner

The combination of the diatomaceous earth and insecticide soap will take care of your fruit fly problem. It will probably take about a week or so for all of the fruit flies to die, but if you're vigilant you'll take care of the problem.

Bottling is easier just put your apples in bottles leaving a small air gap at the top, put lids on then boil for about 20 minutes then allow to cool standing in the boiling water. Done.

Preheat your oven to 25 degrees lower than the package says. Then take a long strip of foil and cover just the edges of the pie( like a halo). The thawed edges will bake so much faster than the rest of the pie. Then bake it as usual. Just check it every 20 minutes or so. Everyone's oven is different.

I'm not sure. In all my days I've never heard of anybody needing to do this. I do know if you leave a small bowl of jello hidden in the back of a large fridge it will be greatly shrunken, much darker and deformed. It makes sense that with a slow heat and some extra water that it would melt, but.... I think I would just start over with fresh jello, fruit and remember to add all the needed liquids. I've been a chef for 43 yes.