Palm sugar was originally made from the sap of the Palmyra palm, the date palm or the sugar date palm. Now it is also made from the sap of the Arenga pinnata (sugar palm) and the nipa palm, and may therefore also be sold as "arenga sugar". Palm sugar is made by making several slits into the stem of a palm tree and collecting the sap. The sap is then boiled until it thickens.