Spherification

Spherification is a landmark technique of molecular cuisine that turns an aromatic liquid into tender spheres with a thin gel skin and a wholly liquid centre. When such a sphere bursts in the mouth, it explodes with clean flavour — an effect reminiscent of caviar or “liquid pearls”. The method, documented by Unilever in the 1950s, was brought into avant-garde cuisine and made famous by the Catalan chefs Ferran and Albert Adrià at elBulli.

At the heart of the process is a chemical reaction between sodium alginate (a thickener from brown seaweed) and calcium ions. In classic (direct) spherification, liquid with alginate is dripped into a bath of a calcium solution: the moment a drop touches the solution, its surface instantly gels, forming a thin film, while inside a liquid remains. The size of the spheres is varied from fine “caviar” to large “ravioli”. The reaction can be stopped by rinsing the spheres in water so the skin does not thicken. Spherification allows juice, stock, a cocktail, or purée to be served in an unexpected form that surprises with texture and gives a vivid burst of flavour. It is one of the most recognisable signs of modern avant-garde gastronomy.