Set a kettle of water over high heat and bring to a boil.
Pour the powdered jello packet out into a medium mixing bowl. Once the water is boiling, measure out one cup of hot water and pour into the bowl. Whisk until smooth.
Whisk in the cold water to lower the temperature. Then whisk in the liquor.
Pour the liquid jello shot mix into 12 to 16 (1.5-2 ounce) disposable cups. Place the cups on a rimmed baking sheet (or in a baking dish) and move to the refrigerator. Chill for 90 minutes, or until solid.
If making multiple flavors of jello shots, pour the powdered jello packets into separate bowls to keep the colors separated.
Jello Shot Cubes:
If you’d like to make jello shots without the disposable cups, you can use an ice cube tray as a mold. Or you can pour the jello mixture into a small baking dish, then cut it into squares once it has set.
In ice cube trays, let the jello shots set in the refrigerator, then place the trays in a pan of warm water for 1-3 minutes to loosen the shots, so they slide out. (Think old-school jello molds.) If your ice cube trays are thick and the jello shots won't come out, run warm the water over the top of each jello shot until it flips in the tray.
Rainbow Jello Shots:
You can also make rainbow jello shots by making 5-6 flavors and layering them all in each cup. Each batch must be made and chilled separately to keep the layers/lines crisp.
Wait at least 30-60 minutes before adding the next layer. Every time you add a flavor you multiply the batch by at least 12. Therefore, making jello shots with 5 colors would create 60+ jello shots!
Jello Shot Recipe Variations: Try making basic jello shots with intriguing flavor combinations… Mango Jello + Coconut Rum. Black Cherry Jello + Whiskey, Pineapple Jello + Passion Fruit Vodka, Watermelon Jello + Tequila.You can also swap the ½ cup of cold water for something else like coconut milk, lime juice, orange juice, or coffee. Be creative!