The procedure I followed this time:
I started using the microwave to heat up the water. Then I pour both cold and hot water in a bowl, then the package of jello.

Previously I always cooked on the stove. After boil I would pour the jello in the pan, then to a bowl and then the cup of cold water. Never had a problem with that.

With the new method my jello is not getting firm in the refrigerator. Why (not)?

  • 1
    What temperature do you end up with when doing the hot and cold water mix? It may just have been too cold... also, you sent me on a search for how gelatine reacts to being treated too cold instead of too hot!
    – Layna
    Commented Sep 13, 2017 at 7:10
  • 4
    Why did you mix the hot and cold water?
    – Catija
    Commented Sep 13, 2017 at 15:47
  • I suspect that this could be saved if you heat it up, then let it cool again. Stove would be better, but if you're careful, you could do it in the microwave. (you need to pull it when it's hot, but below the boil ... and I'd stir fairly frequently)
    – Joe
    Commented Sep 15, 2017 at 21:04
  • The procedure using the microwave should be no different from the stove procedure; all the stove does is boil the water (and thats what the microwave should do too).
    – Batman
    Commented Sep 16, 2017 at 0:44

3 Answers 3


It's not working because you're trying to set jello to lukewarm water - from mixing the hot and cold and then adding the jello.

The hot water needs to be added first, then the jello, then the cold water, then refrigerate, in that order.

  • 2
    And make sure to stir well after the jello is added, and before the cold water.
    – Joe
    Commented Sep 15, 2017 at 21:02
  • Gelatin takes a few minutes to dissolve with stirring even in just boiled water. Commented Sep 26, 2018 at 23:35

After some reading: are you sure your water-temperature is not tool cold at the start?

This page says the following about gelatin:

But gelatin proteins don’t readily form bonds with one another. Heat causes them to initially unravel and disperse just like any protein. They never form new bonds, though, so the liquid in which they’re dispersed stays fluid.

So, if not heated enough, the unravelling may not have happened properly, and the process fails.


Correct Procedure for Jello:

  1. Heat water (boil)
  2. Dissolve the Jello powder in the heated water
  3. Add cold water
  4. Refrigerate to set

from http://www.molecularrecipes.com

Temperature (gels and melts): Will hydrate at 50°C/122°F, but it's pretty standard to just boil it. Sets at 15°C/60°F, but sets much faster chilled, around 1°C/34°F. Melts between 25°C-40°C/77°F-104°F, depending on concentration.


You can just heat the water above 50°C/122°F and dissolve the Jello powders, and let it cool to set.

But is much faster to dissolve in boiling water and then add cold water and refrigerate to set.

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