If there ever was a day to eat green candy, St. Patrick's Day would be it. But is there something better than the banality of green candy swarming the streets on St. Patty's Day? Yes—glowing green candy, and Instructables user BrittLiv wants us to show you how it's done.
She puts her chemical engineering smarts to work for you with her glowing green candy, aptly named "kryptonite candy." If you're a Superman fan, you'll instantly recognize the resemblance to the fictitious glowing green mineral—Superman's own Achilles' heel. But one superhero's weakness is easily one leprechaun's strength, making this the perfect treat for any Irish party. I'm sure it would go nicely with your green Guinness. Slainte!
She first experimented with fluorescein, a dark red fluorescence powder which is soluble in water and alcohol, but points out that it can have adverse reactions like nausea and vomiting, which is obviously something you shouldn't be putting in your food.
Next idea would be quinine, a bitter crystalline compound used in tonic water. If you've seen glow-in-the-dark foods before, this is probably the phosphorescent substance being used. But for making homemade candy—it's not the right choice due to its melting point, which is too close to the temperature needed to make the candy. Therefore, the best food-grade chemical to use would be riboflavin, because of its high melting point.
Riboflavin is non-toxic (a plus) and easily found in drugstores and supermarkets, under the name vitamin B2 or additive E101. Why riboflavin? Besides the high melting point, it fluorescents yellow under ultraviolet (UV) light, and even under direct light. It is destroyed by light exposure, but the process is slow, so it doesn't really matter for this kryptonite candy.
- Sugar (250 grams)
- Vitamin B2 pills
- Green food coloring
- Mint oil (or any other tasty oil)
- Aluminum foil or powered sugar
- Quartz crystals (for molds)
- UV light
- Small pot
- Candy thermometer
- Only use vitamins labeled as B2. Do not use B or any mixed vitamins, and especially avoid B3 (niacin).
- Half of a vitamin B2 pill will be fine, but if you choose to use more, don't exceed 45 mg. It won't enhance the glowing effect anyway.
First up is making the molds, for which there are two methods. You can use either, or a combined version of the following:
- Pour powdered sugar (or cornstarch) into a casserole dish. (Brown sugar also works well.)
- Carefully flatten it with a spoon.
* Try using quartz crystals to make the mold, by pressing them into the powder sugar.
This is an easier method, where you simply crumple, then fold the foil to form, as shown in the following picture.
Firstly, mix the vitamin B2 pill with 150 ml of water.
Then, place on the stove and add the sugar.
Slowly heat the mixture to a boil, while stirring.
Let it cook until it reaches 300°F, then add the mint oil and food coloring, then proceed immediately to Step 3.
- Cook the mixture in as little light as possible for a better glow effect. Remember, riboflavin is slowly destroyed by light, so the less you have the better, but with the amount you're working with, it won't make too big a difference.
Now for the fun part—pour the sugar into the mold and let it harden.
Before serving, make sure to get rid of all the sharp corners, because you can actually cut yourself pretty badly. BrittLiv states that she cut her thumb severely on it. Maybe it is really kryptonite!