Producing Raw Sugar from Sugarcane-The juice is extracted from sugarcane by passing the stalks between a series of rollers under heavy pressure. A large part of the non-sugar solids dissolved in the juice is removed by "clarification," which consists of treating the juice with lime and sometimes other substances, and heat. Then, most of the water, the largest constituent of the clarified juice, is evaporated, reducing the thin juice to a relatively thick sirup. Evaporation of the sirup is continued until as much of the sugar as possible is crystallized.

The cane juice, now reduced to a mixture of sugar crystals and molasses, is passed through a centrifugal which separates the molasses from the sugar. The resulting products are raw sugar and blackstrap molasses.

Raw sugar as now produced averages about 97 per cent sucrose, although the standard for price quotations is 96 per cent; it is usually of a light brown color largely because all the molasses has not been removed.

Blackstrap molasses is a heavy, viscous liquid, containing about 52 per cent total sugars, dextrose and sucrose. It is used mainly in the manufacture of industrial alcohol and for livestock feed.

Other by-products include bagasse, the crushed fiber of the cane, and "mud" or filter press cake obtained from clarification.

Making raw sugar efficiently requires a large investment in plant and machinery and is much more complex than indicated in this simplified outline.

Some mills process sugarcane into sugar for direct consumption in the form of refined or partly refined sugar. The most common type of partly refined direct-consumption sugar used in the United States is "turbinado," sold mainly to industrial users. Turbinado sugar contains a higher percentage of sucrose than does raw sugar but less than refined.

Refining Raw Sugar-Most of the raw sugar produced in Cuba and other "offshore" areas is further refined in separate plants—the refineries —until it is virtually 100 per cent pure sugar or sucrose.

Nearly all the sugar supplied by offshore areas to the continental United States is shipped in raw form for further processing in refineries here. These refineries, with minor exceptions, are located in or near coastal cities where raw sugar can be received by relatively cheap ocean transportation.

Some sugar is refined before shipment, but since 1934, when the United States first adopted its sugar quota system, which restricted marketings of sugar from all producing areas, the volume of refined sugar entering the United States has also been limited.

In the refining process, the small amount of non-sugars in the raw sugar is removed. This is done by washing with water in a centrifugal,