A hydrocolloid or aqueous solution comprising a poly alpha-1,3-glucan ether compound is disclosed having a viscosity of at least about 10 centipoise (cPs). The poly alpha-1,3-glucan ether compound in these compositions has a degree of substitution of about 0.05 to about 3.0. Also disclosed is a method for increasing the viscosity of a hydrocolloid or aqueous composition using a poly alpha-1,3-glucan ether compound.