What You Need to Know
The process relies on ionic cross‑linking between the carboxyl groups of sodium alginate and divalent calcium ions, forming a viscoelastic network that traps the liquid core. The gelation is rapid and exothermic, but at culinary temperatures the heat released is negligible. By adjusting alginate and calcium concentrations, immersion time, and temperature, chefs control shell thickness, translucency, and buoyancy.
The Science
Primary Reaction
Ionic cross‑linking of sodium alginate with calcium ions to form a viscoelastic gel network.