Processed sugar comes from two main agricultural crops in several stages of refinement toward purity of a chemical compound called sucrose. Choosing the best package of sugar at your local market is, first, a preference for one crop or the other, and second, the degree of refinement you may prefer. Fully refined sugar is additionally processed into several different sizes of crystals. Your choice of which size is a very important one based on your intended use.
Most sugar sold at markets worldwide is sucrose. It is a chemical compound called a carbohydrate, which are the sources of energy for nearly all living things on earth. Over 20% of the entire world’s agricultural output is sugar cane — a thick, tall and fast-growing grass. Sugar beet, an underground root tuber, is a secondary but significant source for the world’s sugar demand. The process of extracting and refining the sucrose from these two plants are fairly similar.
The final refined sugar from canes and beets is practically indistinguishable. Nevertheless, you might prefer processed sugar that is labeled “pure cane sugar.” The plants are pressed, to squeeze out most of their juice. After filtering and treating it for impurities, the juice is boiled to evaporate water and other unwanted liquids. When the thickened juice is allowed to cool, it naturally commences to crystallize into sugar.
Any uncrystallized syrup remaining in this mixture is separated by a spinning centrifuge. This syrup is called molasses, and is your choice of processed sugar when a liquid sweetener is required, such as in some pie recipes. The separated crystals, which typically have a dark, cooked color, is raw sugar. Still somewhat moist, they are often molded and sold as soft, crumbly bricks. Also called jaggery or demerara, raw sugar is readily available in sugar-producing countries but may be hard to find elsewhere.
The majority of raw sugar production undergoes further processing to either extract more of its impurities or bleach its dark color. Mill white sugar, also not widely available, is raw sugar that has been bleached white. A cane sugar called blanco directo, popular throughout south Asia, is additionally treated chemically to extract impurities. An organization called the International Commission for Uniform Methods of Sugar Analysis has established standards for measuring and grading sugar quality.
White refined sugar is the most widely distributed and purchased processed sugar in the world, at 99.5% pure sucrose. Trace elements include calcium, iron and potassium. Brown sugar, made by re-mixing refined sugar with varying amounts of molasses, is the second most popular sugar. You should choose brown sugar when its color is preferred, and when the earthier taste of molasses is desirable.
The finished sugar is thoroughly dried, and then passed through sieves to progressively separate the crystal granules by size. The largest is called sanding sugar and is often sprinkled decoratively on baked cookies. Other similarly coarse-grained sugars will not melt from heat alone. The majority of sugar crystals are about 0.02 inches (0.5mm) in size, and is commonly labeled “granulated sugar.” This should be your choice, if but only one is to be made.
Slightly finer than the standard size is baker’s sugar, used almost exclusively for cakes. Close in size and in application, is superfine sugar, also called castor sugar. Their smaller grains dissolve more quickly in liquids, and are therefore preferred for flavoring drinks and making fluffy meringues or mousses. You can make these yourself by grinding regular granulated sugar in an electric appliance.
Powdered sugar is industrially ground to the consistency of dust. In order of progressively smaller particles are: 10X sugar, confectioner’s sugar and icing sugar. All are quick to dissolve at the slightest exposure to heat or liquid. To prevent this happening from ambient moisture in the air, powdered sugar is usually mixed with a small amount of absorbent cornstarch. These are your best choices for a processed sugar incorporated into viscous mixtures like cream frostings which are not meant to melt or liquefy.