After an enlightening Smoke & Mirrors cooking course with James Viles at Signorelli Gastronomia, Angry and I decided to attempt spherification of liqueurs. Shots without the need for a shot glass. It came off really well. We made spheres of Southern Comfort and Coke, and of straight Frangelico.
Here’s how we did it.
- Dissolve 30g of Calcium Chloride (CaCl2) in a 2L bath of cold water. We used tap water with about 2 cups of ice. The Calcium Chloride warms up the water as it dissolves, so the ice is mainly to keep it at room temperature. Be aware that Calcium Chloride is mildly toxic and may irritate or burn: don’t ingest it, and wash your hands after touching.
- Fill another shallow bowl to about 10cm deep with tap water. This is for rinsing the Calcium Chloride off later.
- Measure 500g of spirit into a jug or cup with a spout (note: 500g is not the same as 500ml). Slowly and carefully dissolve 2.5g of Sodium Alginate (NaC6H7O6) in the spirit, stirring constantly. It won’t dissolve fully right away, so warm the liquid in a microwave in 10 second bursts, stirring in between, until it’s warm to touch.
- Bring the liquid back down to room temperature in the freezer. Alternatively, do step 2 ahead of time to avoid this delay. By now we were drawing a crowd, but if you’re prepared earlier it will look less like chemistry (but correspondingly more like magic).
- Fill a tablespoon with spirit, pouring into the spoon. Rest the back of the spoon on the surface of the Calcium Chloride bath, then the slowly but smoothly twist the spoon over, pouring out the liquid. The surface of the spirit will gel immediately as the Alginate reacts with the Calcium Chloride and the blob will draw itself into an approximate sphere.
- Leave the sphere in the bath for about 5 minutes, then spoon it out, draining excess Calcium Chloride solution, and drop it in the rinsing bowl. Ready to serve!
You can pick up a sphere from the water bath with your fingers, carefully, and pop it in your mouth. Then squeeze until it bursts with a shock of flavour and alcohol. Unlike a traditional shot, this one will cover your tongue so you’ll really taste it.
The pouring technique can take a little practice in order to avoid odd shapes and “tails”. The quantities above are the result of some experimentation. Too much Alginate and the spirit won’t pull itself into a sphere before gelling, too little and it won’t hold together at all. Use a digital scale to measure, preferably with 1/10 gram precision. We also tried straight Tequila, without practicing beforehand, only to discover that it didn’t hold together at all. Possibly it’s too acidic.