Thickeners and Gums

The dividing line is whether a hydrocolloid thickens or sets. Xanthan Gum and Sodium Carboxymethyl Cellulose thicken without gelling, and xanthan is strongly shear thinning, which is why it holds a suspension at rest yet still pours. Carrageenan, Agar Agar, Gellan Gum, Sodium Alginate, Konjac Gum and Edible Gelatin all gel, but differently: agar is brittle and sets high, gelatin melts near body temperature, low acyl gellan is firm and clear, high acyl gellan soft and elastic.

Solubility and ions then decide the process. Xanthan and sodium alginate hydrate in cold water, while carrageenan, agar and gellan need heat. Kappa carrageenan requires potassium to gel, alginate sets with calcium and can do so without heating, and konjac gum gels only under alkali, although it thickens strongly alone and reinforces xanthan. Viscosity grade, gel strength and mesh are the numbers on which offers compare.