What You Need to Know
The process relies on ionic cross‑linking of sodium alginate chains by divalent calcium ions, forming a thin, flexible gel network that encapsulates the liquid. Alginate concentrations of 1–2 % (w/v) and calcium chloride solutions of 0.1–0.5 % (w/v) are typical, with the bath temperature maintained at 18–25 °C to preserve viscosity and prevent premature gelation. Immersion times of 30 s to 5 min control shell thickness and integrity, while the acidity and sugar content of alternative liquids such as coffee, wine, soy sauce, and fruit juices influence the required calcium concentration and time.
The Science
Primary Reaction
Cross‑linking of sodium alginate chains by divalent calcium ions forming a gel network