Agar agar is made from algae species belonging to the Gracilaria, Gelidium and Kappaphycus groups. These algae are found in waters in Southeast Asia from Indonesia to Japan and are harvested wild or cultivated in shallow coastal waters.

The red algae used are usually less than one metre in size and have bushy branches.

Many coastal dwellers in Southeast Asia, from Indonesia to Japan, have small algae fields in the tidal zone. The algae are also harvested in the wild. Wet, dried or dried, the algae are heated in water in factories or cooperatives to extract the agar agar.