Twentythree

With just four quick steps and a very special ingredient, anyone can make this spectacular fluorescent jelly!

Over the past year, Japanese Twitter users have been trying their hand at a luminescent dessert they’re calling “Cherenkov Jelly“. Underwater nuclear reactors give off a blue glow due to Cherenkov radiation, and this sweet does exactly the same thing, only using a different ingredient to bring out its fluorescence under the glow of a backlight.

Using just a few simple ingredients, you too can create the mysterious looking sweet at home. The one secret ingredient you can’t do without, however, is tonic water, as the presence of quinine in the drink makes it glow under ultraviolet light.

▼ If you hold a black light over any bottle of tonic water, you’ll be able to see that it glows on its own.

As jelly crystals aren’t easy to find in Japan, we made the jelly from scratch, using the following ingredients.

Gelatin leaves
Tonic water
Mint leaves
Curaçao liqueur
Sugar or Japanese gum syrup

If you’re able to use jelly crystals, then the recipe becomes a whole lot easier, as you already have all the gelatin, sugar and flavour you need. Simply make the jelly as usual, preferably using a blue-coloured mix for a brighter glow, and use tonic water instead of regular water to obtain the fluorescent result.

Method:

1. Soak 10 gelatin leaves in water for 3 minutes until soft.

2. Bring 300 millilitres (10 ounces) of tonic water to the boil and add 1/4 cup sugar and 1/2 cup of mint leaves.

3. On a low heat, add the softened gelatin leaves until dissolved.

4. Turn off the heat and add another 200 millilitres (6.8 ounces) of tonic water. Remove the mint leaves and stir in 1/2 cup of Curaçao liqueur.

5. Stir and let stand for 15 minutes until cool.

Then all you have to do is pour the cooled mixture into little cups, moulds or glasses and leave them in the refrigerator for about four hours until set.

We used several types of glasses to make our jellies, so we could see how the different shapes would glow in the dark. Under natural light, they all looked like ordinary desserts.

▼ But under ultraviolet light, they shone brightly with a beautifully eerie glow.

While the glow-in-the-dark treats are perfect for Halloween, they can be used year-round as a fun way to surprise friends and guests at all types of parties and get-togethers. Fluorescent jellies are a memorable way to end any meal!