Spherification is the process of creating spheres of varying sizes from a viscous liquid solution. The resulting sphere ends up with a thin membrane encompassing a liquid solution that bursts in your mouth when pressure is applied. Theses spheres are sometimes called caviar, ravioli, spheres, gnocchi, or eggs. The effect was first used in a culinary sense by Ferran Adria at the famed el Bulli and has since been used in countless restaurants and soon at home by you.
Spherification is the result of a gelling that occurs when a hydrocolloid (a substance dispersed even throughout water) reacts with a calcium ion coagulant such as calcium lactate or calcium glutonate. The tension of the submerging solution forces the object into a set shape.
There are two main types of spherification: