mother liquor

Mother liquor, also known as mother water or mother liquid, is the residual liquid left after crystallization has occurred and the readily crystallizable substances have been removed. In sugar processing, this liquid is called molasses.12

Molasses is a syrup that remains after sugar crystals are separated from cane or beet juice through centrifuging. This separation happens multiple times during manufacturing, yielding different grades of molasses. The first extraction produces a lighter, sweeter molasses, while subsequent extractions result in darker, heavier molasses. The final extraction yields blackstrap molasses, a thick, dark product from which practically all crystallizable sugar has been removed.2

Molasses is a significant by-product of sugar production. Lighter grades are edible and used in baking and candy-making, and for producing rum. Lower grades, like blackstrap molasses, are used in animal feed and for industrial production of products such as vinegar and citric acid. Additionally, molasses can be fermented to produce ethanol. Modern sugar factories may also practice molasses desugarization using processes like ion exclusion to recover more sugar and increase overall yield.23