Molasses  or black treacle (British English) is a viscous substance resulting from refining sugarcane or sugar beets into sugar. Molasses varies by the amount of sugar, method of extraction, and age of plant. Sugarcane molasses is primarily used for sweetening and flavoring foods in the United States, Canada, and elsewhere. Molasses is a defining component of fine commercial brown sugar. It is also one of the primary ingredients used for distilling rum.
The word molasses comes from melaço in Portuguese, a derivative (intensifier) of mel (honey) with Latinate roots. Cognates include Ancient Greek ? (méli) (honey), Latin mel, Spanish melaza (molasses), Romanian "miere" or "melas?", and French miel (honey).
Cane molasses is an ingredient used in baking and cooking. It was popular in the Americas prior to the 20th century, when it was plentiful and commonly used as a sweetener in foods and an ingredient for brewing beer during colonial times; even George Washington published a molasses beer recipe.
To make molasses, sugar cane is harvested and stripped of leaves. Its juice is extracted, usually by cutting, crushing, or mashing. The juice is boiled to concentrate it, promoting sugar crystallization. The result of this first boiling is called first syrup ('A' Molasses), and it has the highest sugar content. First syrup is usually referred to in the Southern states of the United States as cane syrup, as opposed to molasses. Second molasses ('B' Molasses) is created from a second boiling and sugar extraction, and has a slightly bitter taste.
The third boiling of the sugar syrup yields dark, viscous blackstrap molasses ('C' Molasses), known for its robust flavor. The majority of sucrose from the original juice has crystallized and has been removed. The caloric content of blackstrap molasses is mostly due to the small remaining sugar content.
Unlike highly refined sugars, it contains significant amounts of vitamin B6 and minerals, including calcium, magnesium, iron, and manganese; one tablespoon provides up to 20% of the recommended daily value of each of those nutrients. Blackstrap is also a good source of potassium. Blackstrap molasses has long been sold as a dietary supplement.
The exaggerated health benefits sometimes claimed for blackstrap molasses was the topic of a 1951 novelty song, "Black Strap Molasses", recorded by Groucho Marx, Jimmy Durante, Jane Wyman, and Danny Kaye.
Molasses made from sugar beets differs from sugarcane molasses. Only the syrup left from the final crystallization stage is called molasses. Intermediate syrups are called high green and low green, and these are recycled within the crystallization plant to maximize extraction. Beet molasses is 50% sugar by dry weight, predominantly sucrose, but contains significant amounts of glucose and fructose. Beet molasses is limited in biotin (vitamin H or B7) for cell growth; hence, it may be supplemented with a biotin source. The non-sugar content includes many salts, such as calcium, potassium, oxalate, and chloride. It contains betaine and the trisaccharide raffinose. These are a result of concentration from the original plant material or chemicals in processing, and make it unpalatable to humans. So, it is mainly used as an additive to animal feed (called "molassed sugar beet feed") or as a fermentation feedstock.
Extracting additional sugar from beet molasses is possible through molasses desugarization. This 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 market price. As such, it is practiced in the U.S. and parts of Europe. Sugar beet molasses is widely consumed in Europe (for example Germany, where it is known as Zuckerrübensirup). Molasses is also used for yeast production.
Pomegranate molasses is a traditional ingredient in Middle Eastern cooking. It is made from pomegranate juice by adding sugar and lemon juice to it and simmering and reducing the mixture for about an hour until the syrupy consistency is achieved.
Many kinds of molasses on the market come branded as "unsulfured". Many foods, including molasses, were once treated with sulfur dioxide as a preservative, helping to kill off molds and bacteria. Sulfur dioxide is also used as a bleaching agent, as it helps lighten the color of molasses. Most brands have moved away from using sulfured molasses due to both the relatively stable natural shelf life of untreated molasses, and the 'off' flavor and trace toxicity of low doses of sulfur dioxide.
Molasses is composed of 22% water, 75% carbohydrates, no protein and very small amounts (0.1%) of fat (table). In a 100 gram reference amount, molasses is a rich source (20% or more of the Daily Value, DV) of vitamin B6 and several dietary minerals, including manganese, magnesium, iron, potassium, and calcium (table).
The sugars in molasses are sucrose (29% of total carbohydrates), glucose (12%) and fructose (13%) (data from USDA nutrition table).
Molasses can be used:
Mixing tobacco with molasses is a very ancient habit. A WHO report dates back "the addition of molasses to burley tobacco in the nineteenth century to create 'American' blended tobacco". [E]arly health-oriented anthropological research on hookah smoking showed that it [...] can be traced back [to] the 17th century.
Hookah users inhale smoke, which is generated by heating hookah tobacco that is fermented with molasses and fruits and combined with burning charcoal.