thumb|Clockwise from top left: White refined, unrefined, brown, and unprocessed cane sugars
thumb|upright=1.05|Brown sugar [[crystals]]
Brown sugar is a sucrose sugar product with a distinctive brown color due to the presence of molasses. It is either an unrefined or partially refined soft sugar consisting of sugar crystals with some residual molasses content, or produced by the addition of molasses to refined white sugar. Commercial brown sugar contains from 3.5% molasses (light brown sugar) to 6.5% molasses (dark brown sugar) based on its total volume. Based on total weight, regular commercial brown sugar contains up to 10% molasses. Brown sugars are graded numerically according to how dark they are, with higher numbers correlating with darker sugars. The most common gradings are 6, 8, 10 and 13. In the 19th century United States the same meaning of the words raw sugar, brown sugar and muscovado was also noted: "Raw sugar, commonly called muscovado or brown sugar, not advanced beyond its raw state by claying, boiling, clarifying or other process".
In the mid 20th century, 'brown sugar' could refer to two products. It could be a raw sugar which had been centrifuged to a purity of about 97% pure sugar, and that was offered as brown sugar in health food shops. However, in most cases it was white sugar to which molasses had been added. For the latter, a consumer magazine said, "contrary to opinion, this brown sugar is a product of the refinery." The most important consideration is that the term 'brown sugar' now came to refer to a product for consumers, instead of referring to a type of sugar that was processed by sugar refineries.
Smear campaign
In the late 19th century, the newly consolidated refined white sugar industry, which did not have full control over brown sugar production, mounted a smear campaign against brown sugar, reproducing microscopic photographs of harmless but repulsive-looking microbes living in brown sugar. The effort was so successful that by 1900, a best-selling cookbook warned that brown sugar was of inferior quality and was susceptible to infestation by "a minute insect". This campaign of disinformation was also felt in other sectors using raw or brown sugar such as brewing;
Production
Brown sugar is typically produced by adding sugarcane molasses to completely refined white sugar crystals, with color varying by the amount of molasses used. Brown sugar prepared in this manner is often much coarser than its unrefined equivalent and its molasses may be easily separated from the crystals by simply washing to reveal the underlying white sugar crystals; in contrast, with unrefined brown sugar, washing will reveal underlying crystals which are off-white due to the inclusion of molasses. The addition of molasses, beyond changing the flavor, changes the sugar's characteristics during cooking, increasing the tendency for browning and making the sugar more hygroscopic. Natural brown sugar was "the raw sugar, not the brown sugar most easily obtained, which usually is white sugar artificially colored." The term was devised to distinguish brown sugar that still contained part of its molasses from brown sugar made by adding molasses to white sugar.
Traditional types of brown sugar
Traditional brown sugars are called by various names, such as panela, rapadura, jaggery, piloncillo, and others used regionally.
Muscovado from the Portuguese ', was the most common type of raw sugar and was also called brown sugar.
Kokuto
A similar Japanese version of uncentrifuged natural cane sugar is called kokuto () or kurozato (). This is a regional specialty of Okinawa and is often sold in the form of large lumps. It is sometimes used to make shochu. Okinawan brown sugar is sometimes referred to as "black sugar" for its darker color compared to other types of unrefined sugar, although when broken up into smaller pieces its color becomes lighter. Kokuto is commonly used as a flavoring for drinks and desserts, but can also be eaten raw as it has a taste similar to caramel. Kokuto is also an important local industry on Amami Ōshima, Kagoshima Prefecture; sugarcane cultivation and the production of brown sugar in Japan was first recorded on the island around 400 years ago, using techniques that had been developed in Fujian Province, China, and spread across the Japanese archipelago after that point. It is also the preferred type of brown sugar in Taiwan where its production formed a crucial part of the island's economy in the 19th and early 20th century under Japanese colonial rule. It is highly appreciated for its flavor in various beverages like milk tea and bubble tea.
Culinary use
Brown sugar adds flavor to desserts and baked goods. Due to its high molasses content, muscovado brown sugar contains more moisture and stronger flavor than other brown sugar types, affecting the moisture and taste of some recipes, especially in baked products.