Gin Shots With Glowing Tonic Cubes + Tesseract Centerpiece

If you ever ordered a gin and tonic in a dodgy club you might be aware of the fact that tonic glows under blacklight (due to the quinine). After reading this post on Io9 I knew I wanted to make tonic jelly. But instead of making gin and tonic jelly shots I made tonic cubes floating in an ice cold shot of gin. But what I really wanted to accompany this drink was a jelly Tesseract centerpiece. Unfortunately my first (and my second actually) attempt using only agar agar failed and I ended up with a coarse gel and nowhere near a stable jelly. Here is how I finally created the tonic cubes, big and small.


  • 3 liters of tonic (cheap apparently has just as much quinine as expensive, I checked)
  • 6 packets of agar agar (this should set 6 liters of fluid on its own, but with tonic it doesn't)
  • 6 packets of gelatin sheets (this should set 3 liters)
  • 750 grams of sugar
  • 1 bottle of ice cold gin

 Square Mould

Scandalously I am not currently in the possession of a square pudding mold. So instead I made my own using 5 tiles I stole from my gran's cellar, a very generous amount of ducttape (truly a girls best friend) and some quick dry silicone.

Stupid Stupid Agar Agar

Agar does not set tonic into a proper jelly. Not even if you use twice the flipping amount needed. Why? I don't really know but I think it might have something to do with the quinine being somewhat similar to tannins. Tannins can prevent agar to set and I guess quinine is the same. So  you can make your tonic using only gelatin but I think the agar does add a firmness to the final jelly (so you can play with it, which is always fun)


Defizz your tonic a bit before adding the agar. Please... do it. Mentos have nothing on agar powder.


Determine the amount of tonic needed by filling up your mould and measuring it, (make sure to make some extra for the actual small cubes), put it in a big pan. If you want to counteract the bitterness you can also add some sugar. I used 250 grams per litre as per the instructions on the agar packet.


Now add the agar and hope and prey it doesn't explode in your face.


Agar needs to properly boil for about 5 minutes to activate. Once it has boiled let it cool down to 80 Celsius before adding the gelatin. Once it is dissolved pour into your mould. I used a simple microwave container as the mould for the small cubes.

Now wait

Agar sets at room temperature within a couple of hours but gelatin can use a night in the fridge. Dip into some hot water to get it out of the mould. Because I also used agar, this jelly is quite easy to cut. Add some cubes to a shotglass and pour over some ice cold gin. 


Under the blacklight it becomes glowy bouncy magic.


Unfortunately the tesseract jelly doesn't keep its transparency under blacklight but it still looks quite impressive. Plus because it is quite sturdy it is hard to stop slapping it around.

The Tesseract is MINE!!!

So, after a lot of frustration trying to take a passable photograph under blacklight, this happened. I may or may not have sampled a little bit of the glowy stuff.

I´m still picking bits of jelly out of my hair. Avengers rewatch party anyone?


  1. You're a genius Tess ! Ellis

  2. I find it impossible to set anything with agar without that stupid sandy texture. I even tried using filtered water in case hard water was the problem.

  3. Hey, thanks for this! Great stuff. Important question though- how many Litres total did the recipe make up?

    6L total (with both agar and gelatin mixed in) or 9L with agar mixed to 6 litres, then 3 litres of gelatin added?

    Thanks! Neeeeed to make this at home :P