Around Christmastime, thoughts of molasses are generally tied to holiday cookies. I know I made my annual batch last week! All through the year, molasses is also a widely used feed ingredient. But despite the long history and broad applications of molasses in livestock nutrition, it seems to be a feedstuff that doesn’t receive much discussion.
When someone says “molasses,” they are probably talking about the common co-product of the sugar cane industry. Molasses can also be produced from sugar beets, citrus, and wood, albeit with some differences in composition and characteristics.
This simplified schematic illustrates the key steps in the production of sugar and molasses from sugarcane. The molasses is typically re-boiled and centrifuged three times to ensure extraction of as much sugar as can be recovered economically. Molasses left at the end of these intermediate processes is termed A, first, or mild molasses (after the first boil) or B, second, or dark (after the second). The final, or “C” molasses, is also known as blackstrap molasses, or in some countries, treacle. It will contain roughly 50 to 60% sugar; 35 – 40% as sucrose, and the remainder as glucose and fructose. Blackstrap may be diluted with water to a set concentration to facilitate handling and standardize trade.
Talk the Talk
The following terms are the basis for defining and discussing molasses:
Brix. Degrees Brix (often labeled °Bx) is based on a relative density scale, and represents % of sugar (sucrose) by weight (g/100 ml). While it is actually indicative of specific gravity, it is used to approximate solids content. Brix readings are temperature dependent. In practice, the term brix is used in calculations as a measure of substance, i.e., ‘tons brix.’
Hydrometer. Tool used to measure specific gravity (that is, the ratio of the density of a liquid to the density of water), which can be expressed as Brix. The molasses is put in a narrow container that is then placed in another container of water. Obviously, more dense (higher sugar) samples will sink lower in the water. Hydrometers are scaled to equate this level with the correlating °Bx.
Refractometer. Another tool used to estimate Brix. A small amount of solution (molasses) is placed on a pane, and the angle of light shining through it is measured. Since light will bend differently (and predictably) as the amount of sugar in solution increases, refractometer readings can be correlated to a refractive index scale of Brix values.