Molasses is what is left once sugar refiners have taken the sugar
Boil sugarcane juice once and you get sweet cane syrup; boil it twice and a slightly bitter second molasses; a third time yields thick, dark blackstrap, stripped of most of its sucrose. The leftovers of refining ended up sweetening colonial beer, fuelling rum stills and even strengthening brick mortar.
Molasses is the sticky residue of turning sugarcane or sugar beet juice into crystalline sugar. Cane is cut, stripped of leaves and crushed or mashed for juice, which is boiled to concentrate it and coax sugar crystals out. The first round leaves 'A' molasses, richest in sugar and usually called cane syrup in the American South. A second boil gives 'B' molasses; a third leaves 'C', or blackstrap, far more bitter because most sucrose has been crystallised away. The word traces back to the Portuguese melaço, from mel, honey, and the strap in blackstrap may come from stroop, a Dutch word for syrup.
Before the 20th century molasses was a cheap, plentiful sweetener across the Americas and went into colonial beer; one of George Washington's notebooks includes a molasses beer recipe. It still matters in Southern and Caribbean cooking and on Madeira, where it is called mel-de-cana and dates from the islands' era of sugar wealth. Beet molasses is a different matter: about half sugar by dry weight, it carries salts and compounds people find unpleasant, so it mostly becomes animal feed or fermentation stock.
Unlike refined sugar, cane molasses keeps minerals. A tablespoon can supply up to a fifth of the daily value of vitamin B6, calcium, magnesium, iron and manganese. By weight it is roughly 22 percent water and 75 percent carbohydrate, with no protein. Blackstrap's supposed miracle powers were overblown enough to inspire a 1951 novelty song recorded by Groucho Marx and Danny Kaye, among others.
Its uses spread well beyond the kitchen. It is the main raw material for rum, a flavour in gingerbread and some stouts, and the source of colour in certain brown sugars made by blending it back into white. Builders have added it to mortar, early printers mixed it into ink rollers, and gardeners spread it on soil to feed microbes whose by-products may help suppress plant disease. Most brands now skip the sulfur dioxide once used to preserve and lighten it.
Source: Molasses
