It is possible to speed up the setting of Jello by adding ice to the water specified in the preparation instructions. To help the Jello set faster, chefs can replace the recommended amount of water with an equivalent amount of ice.
In a medium-sized bowl, dissolve the mix in 3/4 cup hot water to make Jello set faster. In a glass measuring cup, pour 1/2 cup cold water. Fill the water with enough ice to make it 1 1/4 cup. Pour the mixture into the gelatin and whisk until everything is well mixed. The majority of the ice melts during this procedure, but any unmelted ice should be discarded.
To soften the Jello, place it in the refrigerator for 30 minutes. Refrigerate for up to 90 minutes if you want a soft but firm Jello.