Alginate beads are made using the unique property of alginate, it reacts with calcium to instantaneously gel. When an aqueous solution of alginate is added dropwise into an aqueous solution (calcium chloride solution, calcium lactate solution, etc.) in which calcium is ionized, the gelation reaction occurs instantaneously at the contact surface of both solutions.
The dripped alginate solution becomes viscous so it floats without diffusing into the calcium solution and gelation proceeds while it becomes rounded by surface tension, resulting in a spherical jelly. To color this spherical jelly, dye can be added to the alginate. In addition, to gel the surface coating only and to leave the center as a solution, a special double tube is used to drip alginate and internal liquid simultaneously.
Currently, an increasing number of uses are available to encapsulate colorful foodstuffs, spices, and seasonings, which can be used as flavorings for cuisines.
Artificial caviar, which is colored black by squid ink, is also used in specialized applications.