By Harold McGee
Among sugar-giving trees, certain tropical palms are by far the most generous. The Asian sugar palm (Borassus flabellifer) can be tapped for up to half the year, and yields 15–25 quarts/liters per day of a sap that may be 12% sucrose! Individual trees can give 10–80 pounds of raw sugar every year. Coconut, date, sago, and oil palms are less productive, but still far more so than maples and birches. The sap is collected either from the flowering stalks at the top of the tree, or from taps in the trunk, and then is boiled down either to a syrup called palm honey, or to a crystallized mass, which in India is known as gur (Hindi) or jaggery (English, via Portuguese from the Sanskrit sharkara). These same words are also used for unrefined cane sugars. Unrefined palm sugar has a distinctive, winey aroma that contributes to the flavor of Indian, Thai, Burmese, and other South Asian and African cuisines. Some palm sugar is refined to make more neutral white sugar.