What is the difference between "stone ground wheat flour" and "whole wheat flour"?
Several kinds of wheat flour are available for sale, with the most popular being enriched and bleached all-purpose flour. The differences between flours come down to the type of wheat, the parts of wheat included, the processing of the wheat, and any additives made to the flour.
Whole-wheat flour contains the germ (the embryo of the wheat kernel) and is more flavorful than regular all-purpose flour which does not include the germ. Because whole-wheat flour contains the germ and bran, it contains more nutrients and fiber as compared to enriched flour. Whole-wheat flour should be stored in the refrigerator to prevent the germ oils from becoming rancid.
Almost all the flour sold is steel ground, meaning a large machine with steel hammers or rollers crushes and grinds the wheat kernels down. This is a very efficient means of producing flour, but the steel surfaces heat up with the high speed and volume of wheat being ground. This heat causes some of the vitamins in steel-ground flour to be destroyed during the grinding process.
Alternatively, stone-ground flour is produced by the relatively slow grinding of large stones together (with the wheat in the middle). This type of flour is harder to find and almost always leaves the germ intact when producing whole-wheat flour. There is no heat buildup, so all the nutrients stay intact as the flour is made.
Look for the words "Stone Ground Whole Wheat" on the front of the package, and the very first ingredient on the back should read "whole-wheat flour."