A variety of bread made from grains of rye grass that have been ground into fine flour providing a slightly sweet-sour flavor. The rye flour does not contain enough protein to develop the gluten necessary for the bread to rise sufficiently without combining it with wheat flour. The wheat flour contains the protein necessary for gluten development, allowing the bread to rise. Rye flour produces a denser and darker loaf of bread. The darkness and flavor of the loaf will depend on the darkness of the rye flour and the amount of rye flour used. Just a small amount of rye flour combined with wheat flour will add a distinctive flavor to the loaf.
As an alternative to the heavy rye flavor, many bakers prepare a rye bread that combines white flour with rye flour to create a "marbled" Rye Bread. Marble or Marbled Rye Bread has the distinctive rye taste but more subtle in flavor than the all rye or rye and wheat combination.