Open cans of cherries and drain the juice into a measuring cup. Add cold water so that you have a total of 2 cups of liquid. Stick the juice/water in the fridge to chill for a few minutes.
Bring 2 cups of water to a boil. Add water into a microwave-safe bowl.
Add 2 packages of black cherry jello. Whisk for 2 minutes. Make sure that the jello has completely dissolved in the water.
Add the two cups of chilled water and juice into the bowl, along with the black cherries.
Cover and let the jello set in the fridge for 6-8 hours or overnight.