A few years ago, a gene-editing laboratory went viral for creating a Belle Saison yeast that glowed in the dark. The claim was that, with this specially modified yeast, brewers could make beer that glowed fluorescent under black light. We were fascinated by this concept – and skeptical of the potential.
So we put it to the test ourselves. And no matter how hard we tried, we couldn’t get a glowing brew on the other end of it.
We changed directions, did some exploring around the web, and found two potential solutions: tonic water and vitamin B2 (riboflavin). So, we jumped back in and started brewing with both!
How does tonic water glow in the dark?
Tonic water includes a compound called quinine. The synthesized version in tonic water glows blue under blacklight. The mechanism for this is due to quinine’s ability to absorb ultraviolet light and then emit a blue glow in response. Used in the right proportions, this can make for an eerie blue beverage!
What makes riboflavin glow in the dark?
Vitamin B2, riboflavin, glows in a slightly different way from quinine. When UV light hits riboflavin molecules, they become “excited” and in response emit their own bright yellow light! This can be seen in drinks that contain B2, like some Monster Energy drinks.
When riboflavin and quinine are present in the proper proportions, they can be combined to achieve a slime-green ectoplasm glow!
For homebrewed drinks, we would recommend using part tonic water for the brewing liquid – up to entirely tonic water if you want to lean into the “gin and tonic” vibe. Maybe toss in some juniper berries, spruce tips, and coriander to go all-in! The riboflavin should be dosed at approximately 400mg per US gallon AT BOTTLING. Riboflavin eventually breaks down under UV light, just like hops, so it must be stored in dark bottles.
Simple glow-in-the-dark mead recipe
Want to try something simple and tested? Here’s our final recipe from our video on this project1
- 1.25# honey
- 0.2g citric acid
- 0.6g malic acid
- Top up to 1 gallon with tonic water, degas
- EC-1118 yeast
Bottle in pet-nat style at 1.005 after a clean rack onto:
- 400mg vitamin B2
- 1/3 cup erythritol