Reverse Spherification

Reverse spherification is a refined variety of the technique for creating liquid spheres that removes the main limitations of the classic (direct) method. Here the gelling agent and the calcium source swap places: sodium alginate is dissolved in the bath, while the liquid from which the sphere is formed is enriched with calcium (calcium lactate is added).

When a spoonful of such calcium-rich liquid is dipped into the alginate bath, gelling proceeds from the outside inward — a thin skin forms around the drop. The key advantage is that the skin stops thickening as soon as the sphere is removed and rinsed, so a liquid remains inside forever: such “yolks” can be kept for hours and will not turn into a solid jelly. More important still, the reverse method works with products inaccessible to direct spherification: acidic ones (citrus juice), alcoholic ones, and calcium-rich dairy liquids (yoghurt, cream), which do not gel in the direct method. Reverse spherification gives larger, more stable “ravioli” spheres with a thin skin and a clean liquid flavour within. It is a refined tool of modern gastronomy.