Rye flour typically comes in light, medium, and dark varieties—these refer to the relative amount of bran and germ each contains—as well as 100 percent whole-grain rye flour, also called “pumpernickel” flour.
While light, medium, and dark rye flours are sifted to remove some of the nutrient-rich bran and germ, pumpernickel flour is unsifted and should be made from the entire rye kernel. That said, we’ve found that labeling is inconsistent among flours. Many companies simply label their product “rye flour” without any mention of type. And because the U.S. Food and Drug Administration doesn’t regulate how much “whole grain” a product needs to contain to bear that label, any type of rye flour may bear this description on their label.
Fortunately, all this confusion is a moot point for our Deli Rye Bread as well as our Boston Brown Bread. When we made loaves with each type of flour, they all came out just fine, including the pumpernickel loaf. However, we did observe that the darker the flour, the more intense the rye flavor and the more dense the loaf. Some tasters said that the loaf made with light rye tasted closer to a regular wheat bread. If you have a choice, we recommend using medium or dark rye for the best balance of flavor and texture.