Mung bean milk is a by-product of cellophane noodle production and is similar to soy milk, exceot it is made from mung beans. It is a gray-green color and tastes slightly sour and sweet, with an egg-like smell. Although mung bean milk does not look or smell appetizing, most Beijingers love to drink it, especially in spring and winter. It is a very healthy food, with lots of protein, Vitamin C, fiber and sugar.