In the interest of honest and complete coverage of the topic, I’d like to clarify and expand upon the comments made by a contributor about the "brown sugar" typically marketed in the United States and Canada.
Brown Sugar is indeed just white sugar with molasses added to it. But what is not clear to most people is that molasses is what is left over when you refine sugar cane or sugar beets into white sugar.
Some sugars labeled “turbinado” or “demerara” sugars are made from partially refined sugar-juice that have had some of the water driven off by a centrifugal process. The darkest brown sugar, “muscovado” is not centrifuged, but pan dried and pounded to a thick paste like consistency.
Brown sugar and molasses were once demonized by the white sugar processors in the early 1900s as being “impure” – pictures of the molasses and brown sugar were taken with a microscope to show the microscopic organisms that were processed with the cane or beet that made people think that brown sugar and molasses was contaminated. It worked, people stopped buying partially processed sugar, and insisted on the highly processed white form.
Molasses, as a source of carbohydrate, is low on the glycemic index – while there is still some sucrose bound up in the matrix, it is slow to release and doesn’t give you a sugar buzz if consumed. Beet sugar molasses is more deficient in micro-nutrients, like biotin. Sugar cane, however, can have a root system that reaches up to 12 feet underground, which gives it a wider area to acquire nutrient minerals like zinc. Sugar beet roots reach about five feet into the ground and are much less sectionally dense(thick) and are thought to be less efficient that sugar cane roots.
A tablespoon of molasses has about 20 percent of the minerals needed by an adult on a daily basis. It is theorized that the uptake of minerals from molasses may, in fact, yield a higher percentage of usage minerals versus a vitamin pill as the molasses is slower to digest and releases it’s contents more gradually – and thus may not contribute much of it’s mineral content to elimination. Gardeners use molasses to encourage friendly bacterial growth in their gardens. Sugar beet as silage is almost as nutrient dense as corn, and is a major crop export for sugar producing countries (the bulk materials that are left over after sugar production) to countries that produce cattle. Cows love sugar beets, but can choke on them, so grind em up or chop them if you’re using them as feed supplement, after having about 20 percent molasses added back into the mix for lactobacillus growth encouragement. Point is, molasses is GOOD on many levels.
How to make brown sugar from white...
By weight, molasses is about 10 percent of light brown sugar, by volume just slightly more than 6 percent. A good measure is one tablespoon of molasses to one cup of sugar for a light brown equivalent. Another two teaspoons will yield the equivalent of dark brown sugar. If this is how you made your brown sugar, you will need to blend the sugar and molasses in a food processor if you intend to bake with it (cookies), if the sugar/molasses is going into something that’s melted (like caramel) then you do not need to blend it. Brown sugar is soft because molasses is hydroscopic, that is it attracts water molecules – yes regular sugar has water in it from the sucrose, but it’s bound up chemically and not attached in a non-bonded chemical form to the molecule.
To revitalize hardened brown sugar you can either heat it (be careful you don’t melt it) or put a slice of two of bread in the container and come back in a day – the water will have been slowly absorbed and spread into the hardened brown sugar, making it soft again. We typically buy something called “blackstrap molasses” an American coined word, which is simply a made-up, meaningless name – it indicates that the molasses was derived from the third boiling (processing) of the sugar cane or sugar beet. 1st and 2nd boiling molasses (sometimes called green molasses) still has a lot high of sucrose in it and is sold commercially to large food processors, but is not generally available to the public.
Unsulphured molasses means that the sugar cane was mature when processed and did not need the addition of sulphur to help break down the immature sugar cane for processing. Sulfured molasses was made from less mature plants and is more common, most store brand molasses are of the unsulphured variety – where does the other stuff go? Into the baking industry! There is a difference between the molasses from sugar cane and sugar beet, ultimately most sugar beet molasses ends up as feed for animals or for use in making yeast or other things like stout beer – there is a bitter taste to beet molasses and considerable more indigestible bio-mass in the mix.
I hope this information helps! - J.M. in Colorado