Cane molasses
Sulfured molasses is made from young green sugar cane and is treated with sulfur dioxide, which acts as a preservative, during the sugar extraction process. Unsulfured molasses is made from mature sugar cane and does not require treatment with sulfur during the extraction process. There are three grades of molasses, Mild or first molasses, Dark or second molasses, and Black strap. These grades may be sulfured or unsulfured.
To make molasses, which is pure sugar cane juice, the sugar cane plant is harvested and stripped of its leaves. Its juice is extracted from the canes, usually by crushing or mashing. The juice is boiled to concentrate which promotes the crystallization of the sugar. The results of this first boiling and removal of sugar crystal is first molasses, which has the highest sugar content because comparatively little sugar has been extracted from the juice. Second molasses is created from a second boiling and sugar extraction, and has a slight bitter tinge to its taste.
The third boiling of the sugar syrup gives black strap molasses. The majority of sucrose from the original juice has been crystallized but black strap molasses is still mostly sugar by calories; however, unlike refined sugars, it contains significant amounts of vitamins and minerals. Black strap molasses is a source of calcium, magnesium, potassium and iron. One tablespoon provides up to 20 percent of the daily value of each of those nutrients. Black strap is often sold as a health supplement, as well as being used in the manufacture of cattle feed, and for other industrial uses.
Sugar beet molasses
Molasses that comes from the sugar beet is different from cane molasses. Only the syrup left from the final crystallization stage is called molasses; intermediate syrups are referred to as high green and low green and these are recycled within the crystallization plant to maximize extraction. Beet molasses is about 50% sugar by dry weight, predominantly sucrose but also containing significant amounts of glucose and fructose. Beet molasses is limited in biotin (Vitamin H or B7) for cell growth, hence it may need to be supplemented with a biotin source. The non-sugar content includes many salts such as calcium, potassium, oxalate, and chloride. These are either as a result of concentration from the original plant material or as a result of chemicals used in the processing. As such, it is unpalatable and is mainly used as an additive to animal feed (called "molassed sugar beet feed") or as a fermentation feedstock.
It is possible to extract additional sugar from beet molasses through a process known as molasses desugarisation. This technique exploits industrial scale chromatography to separate sucrose from non-sugar components. The technique is economically viable in trade protected areas where the price of sugar is supported above the world market price. As such it is practiced in the U.S. and parts of Europe. Molasses is used for yeast production.
