If you want to know how to make food glow in the dark this Halloween, we’re going to let you in on a spooky secret: You can use tonic water to give your ghoulish goodies a glow. Yes, you read that right. The bubbly drink you use as a Halloween cocktail mixer contains a secret ingredient that will make your food fluorescent.
Tonic water contains quinine, which is derived from tree bark and used to treat malaria. Quinine is also the chemical responsible for tonic water’s bitter taste. When held under an ultraviolet light (aka a black light), the quinine will cause the tonic water to appear a bright blue — which is the perfect twist for an eerie Halloween party dessert spread.
Ready to try it? Give your cupcakes a frightening glow this Halloween with a simple two-part process: First, add 1/4 cup of tonic water to your favorite traditional buttercream frosting recipe. Next, while you let the frosted baked goods cool in the freezer, get to work on a batch of any flavor Jell-O but replace the still water in the instructions with tonic water. You want to make sure the Jell-O doesn’t set so you can use it to glaze the hardened frosting. Then, either dip your frosted cupcakes into the liquid Jell-O or lightly brush the Jell-O mixture directly on the frosting. Repeating the Jell-O glazing process a few times will ensure the frosting really pops under a black light.
One look at your Halloween dessert spread, and your party guests’ face will immediately light up in amazement. The only downside to using tonic water to create glow-in-the-dark treats is that quinine’s bitter taste will make your goodies taste, well, not so good. Freezing your cakes may affect the texture, leaving it dry and crumbly instead of moist. Plus, glazing your frosting with gelatin creates a hard exterior, which means you won’t be biting into soft, fluffy buttercream.
The simple solution in this case would be to use your cupcakes solely as Halloween decorations. If you’d rather not let good Halloween cakes go to waste, you can just leave out glasses of tonic water. This way, the only thing you’re losing is some tonic water — which saves you from having to figure out what to do with the tonic water that’s inevitably left over at every party.