16/03/2026
It began with something that was surprising and somewhat surreal.
During a laboratory visit, I came across a bottle filled with what appeared to be frogspawn. It was in fact a Thai drink made with sweet basil seeds suspended in gel. Strange to look at, but striking too.
Back at The Fat Duck, we had been working extensively with fluid gels made using gellan. I love them because the process creates something that looks like a liquid, but has a viscous thickness to it.
One day in the development kitchen, I doodled a glass divided in two, which set me thinking: could a glass hold two elements side by side? Two liquids, for example, one hot and one cold?
In theory, of course, separating liquids is more or less impossible. In practice, with fluid gels fashioned to exactly the right viscosity, you can create the illusion. They had to be thin enough to sip, yet structured enough not to collapse into each other.
Even then, temperature proved a challenge. Hot feels more fluid in the mouth. Cold feels thicker. The answer was adding more acidity on the cold side, encouraging salivation so that both felt equally fluid.
I developed Hot & Iced Tea back in 2005, and it still surprises guests at The Fat Duck today.