Gelation
Agar gels can be formed in very dilute solutions containing a fraction of 1% agar. In fact gelation is perceptible at concentrations as low as 0.04%. These gels are rigid, brittle, have well defined shapes and sharp melting and setting points. pH noticeably affects the strength of agar gels; as the pH decreases, gel strength weakens down to a pH of 2.5.