I am on a no-sugar diet due to food insensitivity. I crave gummies and would like to make some without adding sugar (say with coconut water) and have them survive (stay firm and not grow mold) out of the fridge for my upcoming travels. How do I do it?
If eating fruit is ok for you, you could boil fruits rich in pectin (without adding water) to a very thick jam, then spread it out thinly onto a sheet of baking paper and let it dry. If your climate doesn't allow the jam to dry in a day or two, put it into an oven on the lowest temperature and leave the oven door slightly ajar. Adding citric acid to the jam improves durability.
Cut the jam into gummy-sized strips before it's completely dry. Dust it with a little corn starch to prevent the strips sticking together. Store them in a container that keeps moisture out.
Apples are well suited for this procedure, that was used in medieval Europe to process left-over apples before they spoiled. Unfortunately, the finished product has a brown color that is not very appetizing.
I think a similar result can be obtained by preparing gelatine with only a quarter of the prescribed quantity of water / juice.