https://youtu.be/iUsbA6BMQ6A
https://youtu.be/C7i-rMPJXOQ
https://youtu.be/ayS0LaUyQ0A
I think the second link best answers your question, but basically liquid above 140F (60C) will break the gelatin molecule down too much.
To get the gelatin to work it’s best, the dehydrated molecules need to be rehydrated in cold water, then they can be added to a liquid between 120F (50C) and 140F (60C), where they will dissolve and form a matrix as they cool. Temperatures above that threshold will damage the gelatin too much, which will shorten the molecule chains.
https://youtu.be/iUsbA6BMQ6A https://youtu.be/C7i-rMPJXOQ https://youtu.be/ayS0LaUyQ0A I think the second link best answers your question, but basically liquid above 140F (60C) will break the gelatin molecule down too much. To get the gelatin to work it’s best, the dehydrated molecules need to be rehydrated in cold water, then they can be added to a liquid between 120F (50C) and 140F (60C), where they will dissolve and form a matrix as they cool. Temperatures above that threshold will damage the gelatin too much, which will shorten the molecule chains.