What You Need to Know
Agar agar is a polysaccharide composed mainly of agarose, a linear β‑(1→4)-linked galactose and 3,6‑anhydro-L-galactose. Upon heating to 85–95 °C the agarose chains disentangle and dissolve, forming a viscous solution. As the mixture cools to 32–40 °C, hydrogen bonding and van der Waals forces drive the chains to associate into a rigid, transparent network that traps water and yields a gel.
The Science
Primary Reaction
Gelation via hydrogen bonding and chain association of agarose upon cooling