Molasses is a thick sweet syrup, often used in cooking. It is a strong smelling and flavorful additive for cookies, breads and many desserts. The difference in the molasses comes from how many times it has been boiled during the manufacturing process. In Britain it is called treacle, a common term for thick liquids and a poetic phrase, as in treacle well.
First, the cane plant is stripped of leaves and juice (usually by crushing or mashing) then the juice is boiled. The first removal of the sugar crystal is called first molasses, which has the highest sugar content. Second molasses, from second boiling, has a slight bitter tinge. The third boiling produces blackstrap, still mostly sugar despite most of the original juice being crystallized. Regular molasses comes from the first boiling, and blackstrap from the third.
Sometimes young cane plants are treated with sulphur dioxide fumes, and some people are sensitive to this. Look for unsulphured molasses.
Blackstrap molasses is very high in copper, and iron, and other minerals. One tablespoon provides up to 20 percent of the daily value of each of those nutrients. Molasses has many healthful benefits, and is full of vitamins and minerals. For this reason many healthy minded people recommended it as a sweetner, though I advise you not to include it in a diet plan until after you have tasted it. Coffee will not taste the same, though the molasses is far better than most harmful fake sweetners. It is starting to be known as a general cure all, much like the old tonics and cure alls from yesteryear. The thick syrup provides a bittersweet strong flavor in beans and ginger breads.
Better grades of molasses are lighter colored and contain more sucrose (sugar) and are most often used in desserts and for the rum. Blackstrap is the lowest grade and mainly used for cattle feed and cheap alcohol. Plants other than sugar cane often yield lower grades of molasses.
Molasses should be stored in a tightly sealed container in the refrigerator or a cool, dry place. Unopened containers should keep for about one year, while opened containers should keep for about six months.
As a side note, molasses is a chelating agent. A rusty object placed in one part molasses and nine parts water will remove rust. It is also is the base material for rum. High vitamins and a chelating agent? No wonder pirates drank so much rum.
Check out the on-line encyclopedia for more info. And a side note of a molasses flood.