syrup remaining after sugar (sugar beet) is crystallized out of cane or beet juice. Molasses syrup is separated from sugar crystals by means of centrifuging. Molasses is separated from the sugar crystals repeatedly during the manufacturing process, resulting in several different grades of molasses; that obtained from the first extraction contains more sugar, tastes sweeter, and is lighter in colour than molasses obtained at the second or third extractions. The third and final extraction yields blackstrap molasses, a heavy, viscous, dark-coloured product that has had all the sugar removed from it that can be separated practically by ordinary crystallization.

The lighter grades of molasses made from sugarcane are edible and are used in baking and candy-making and to make rum. Blackstrap and other low grades of cane molasses are used in mixed animal feed and in the industrial production of vinegar, citric acid, and other products. The molasses obtained from sugar beets has a very low sugar content and is generally inedible. Before 1948 molasses was fermented to make industrial ethyl alcohol, which is now made principally from ethylene, thus decreasing the demand for molasses.

Blackstrap molasses from cane is composed of roughly 55 percent sucrose and other sugars, 20 percent water, 15 percent organic nonsugars, and 10 percent ash.