Agar-Agar is a substance obtained from several varieties of seaweed that grows off the East Indian coast. Agar consists of a mixture of agarose and agaropectin. Agarose, the predominant component of agar, is a linear polymer, made up of the repeating monomeric unit of agarobiose. Agarobiose is a disaccharide made up of D-galactose and 3,6-anhydro-L-galactopyranose. Agaropectin is a heterogeneous mixture of smaller molecules that occur in lesser amounts, and is made up of alternating units of D-galactose and L-galactose heavily modified with acidic side-groups, such as sulfate and pyruvate. Agar was discovered around 1658 by Minoya Tarozaemon in Japan, an innkeeper who was said to have discarded some surplus seaweed soup and noticed that it gelled later after a winter night's freezing.