I really wanted to make glow-in-the-dark oysters. More accurately, I wanted to make oysters fluoresce under ultraviolet light (sometimes called “black light”). Why? Because it’s cool, of course. [If you were hoping for a more noble, practical reason, you’re probably reading this blog by mistake.]
I knew two things before beginning this experiment: 1) the quinine in tonic water fluoresces under UV light, and 2) oysters are “filter feeders,” meaning they trap particles from the water as a means of taking in nutrients. Modernist Cuisine includes a recipe, which is an adaptation from Dave Arnold and Nils Noren, for Beet Juice-Fed Oysters (book 3, page 206). The recipe calls for submerging live oysters in beet juice strained through a 500 micron sieve and letting them feed for 48 hours. The flesh of the oyster turns pink and red as it takes on the microscopic particles of beet juice.
Following this example, I thought there was a good chance that the oysters might filter the quinine out of tonic water in the same way, leading to slightly sweetened oysters that would glow iridescent blue under a black light. In my experiment, however, they did not. The picture you see above is one of my test oysters under a fluorescent UV bulb. Although it looks cool in the photo, it is very much not fluorescing. If I put a white cloth next to the oyster, the cloth lit up like a warehouse rave, but the oyster was only reflecting the bluish hue of the visible light from the UV blub. Interestingly, a portion of the shell just at the hinge is fluorescing (it’s a brighter blue-green in the picture) but I did not achieve my intended result of an iridescent mollusk.
Why didn’t it work? I have a few theories:
- Perhaps the oysters were DOA. Shamefully, I purchased the oysters at the type of grocery store that also sells name-brand cola and US Weekly. I should have known better, and I’ll never do it again, but it’s quite possible that these fugly-ass oysters were dead before I got them home.
- Salt problem? The Modernist Cuisine recipe calls for 2.6% aquarium salt. I’m not sure what that is, so I used regular table salt. Perhaps that’s an important difference.
- Is tonic water lethal to oysters? The shells were still tightly closed when I removed them. I did notice that, for about 30 minutes after I covered the oysters in tonic water, they were releasing a constant stream of very small bubbles from the edges of their shells. I assume this was a result of them circulating the water through their muscular little bodies. But perhaps the fact that the bubbles stopped after 30 minutes is evidence that they didn’t survive the pre-cocktail environment of a bottle of Canada Dry.
- The quinine in tonic water might be inaccessible to the oyster’s filtration system. Either the quinine particles are too large, too small, or for some other reason can’t be filtered by the oysters.
- Not enough quinine? Perhaps everything did work as I anticipated, but the concentration of the quinine was just to weak to show up in the oyster bodies.
I may repeat this experiment with higher-quality oysters and additional quinine. Alternately, if any geneticists out there want to grab the fluorescence gene from a modified zebrafish and put it into a Samish Sweet or a Blue Pool, I’ll gladly shuck and slurp with you!