Thai black rice A black variety of Thai long-grain sticky rice, this rice is not milled (i.e., it is a “brown rice”). Though the rice inside the bran is a sticky rice (and white), because the outer (black) bran layers are left on the grain, the grains of rice do not stick together when cooked, but stay entirely separate. The rice turns a most beautiful, slightly purply black when cooked. Thais use this rice for desserts and other sweets. They usually mix it with an equal quantity of white sticky rice and soak them together. The black rice dyes the white and the white’s stickiness helps the blended rice to stick together when cooked. See Sweet Black Rice Treat.