Why Not Rye?


David Kovacic, Director of Technical Service

Rye breads have always played second fiddle to wheat breads in America.  This is not the case in many European countries where rye bread has been very popular for ages.  The rye grain is extremely hardy, able to grow and thrive in some very harsh climates and soil conditions. It eventually found its way to this country with the early settlers and is grown in regions normally not suited for wheat.  The upper Midwest and Canada are the primary producing regions.  Winter rye, like winter wheat, is planted in the fall, lies dormant during the winter and is harvested in early summer.

The opportunity to increase sales of rye breads and other rye containing bakery products is greater than ever given the evidence of its nutritional value.  Rye is very high in dietary fiber, the highest among the cereal grains.  Diets rich in dietary fiber may help reduce the risk of heart disease, diabetes, obesity and even some cancers.  As consumers strive to increase their intake of fiber, now is the time to promote the health benefits of rye in bakery products.

After wheat flour, rye is the second most utilized cereal grain purchased by bakers.  Rye breads and rolls are the predominant product produced, but rye also finds application in crackers, bars and cereals.  It can be incorporated into muffins, biscuits, sweet goods, bagels and even pizza dough.  The profit and marketing potential of rye should not be ignored.

Rye flours, due to the differences in milling refinement, vary in color, flavor intensity, and baking quality.  As the percentage of the rye grain converted to flour increases (extraction rate), the flour color becomes darker, the rye flavor intensifies, but the baking quality diminishes.  It is the type and amount of rye flour used, as well as the use of rye sours or preferments, that give rye breads their distinctive flavor.  The darker the rye flour, or the greater the quantity used, the greater the rye flavor.

Little attention is given to the protein percent of rye flour.  Rye has less gluten forming ability and thus does not develop the elastic and extensible dough structure that wheat flour does.   Because of this weak gluten, rye breads rely on the quantity and quality of the starch fraction for much of its structure. Without a strong gluten network, dough made with rye flour will not have adequate gas retention if used alone.  Thus, breads made with 100% rye will have low volume and a coarse, dense crumb.

There are higher levels of pentosans in rye than in wheat.  It is believed that these pentosans (gums) found in rye inhibit the hydration and development of the gluten proteins during mixing.  They also contribute to the inherent stickiness of rye dough.  On the plus side, rye breads often have excellent shelf life due to the moisture-carrying capacity of these gums.

Rye also contains an increased level of amylase enzymes. It is these enzymes that convert damaged starch (created during the milling process) into simple, fermentable sugars – sugars capable of being metabolized by yeast.  These sugars are necessary for yeast fermentation, resulting in the production of carbon dioxide gas, ethanol, acids and many flavor compounds unique to yeast leavened baked goods.  Rye amylases are more heat stable, and, gone unchecked, a rye dough can become extremely sticky and difficult to work.  For this reason, rye doughs are often produced at lower pH levels (acidic) through the use of natural or artificial sours.

Rye Flours

Bakers have access to several different types of rye flours.  They are classified according to their color: white, medium and dark.  It is also available as a whole grain product, referred to as rye meal.  Unlike wheat flours, the protein content of rye flour isn’t used to define its baking quality.  However, we can use wheat milling terminology to help describe the different rye flours.

For example, white rye flour is milled from the center of the rye kernel and corresponds to a patent grade.  It is the whitest in color and will contain the least amount of bran.  Medium rye flour is a straight grade and has a darker grey color.  Straight grade flour is the flour produced when the majority of the bran and germ have been removed during the milling process and contains the entire starchy endosperm.  Dark rye flour is comparable to a clear flour grade which is the fraction of flour that was removed from the straight grade to produce patent flour.  Dark rye flour is darker in color and higher in enzymatic activity because these flour streams originate closer to the outer bran layer.

It should also be noted that there are no legal definitions for the terms white, medium or dark rye flour.  Bakers should be mindful when making comparisons between brands or suppliers.

Rye Meal

Rye meal is whole grain rye.  It is the ‘whole wheat flour’ in the rye family.  The extraction rate of rye meal is 100%, since the entire rye kernel has been reduced to flour (meal) – nothing has been added, nothing has been taken away.  The proportions of the natural constituents (protein, carbohydrates, fiber, fat, vitamins, minerals, etc.) of the rye remain unchanged.  Since the bran and germ are partially removed during the milling process, rye flours lack the full fiber and nutritional benefits of rye meals.

Rye meal is available in various granulations, including extra fine, fine, medium and coarse.  The finer the granulation, the less impact it has on the overall loaf volume. The most popular use of rye meal is in the production of pumpernickel bread.  In fact, rye meal is often called “pumpernickel.”  Rye meal is also used as dusting flour instead of cornmeal for rye bread baking.

Other Rye Products

Rye flour and rye meal are the most common form of the rye grain used in baking, but other products are available and offer unique product quality attributes.  Rye flakes are produced by flattening whole rye kernels that have been softened by tempering to a higher moisture content.  Rye chops are whole grain rye that has been cut or broken into irregular shaped pieces.  It is often available in different granulations.  These products are often used in multi-grain products where a nutty, crunchy texture is desired, or as a topical application.  Often these items are soaked prior to use to make them softer and more palatable.

Usage Levels

Traditionally (in this country), wheat flour is used in combination with rye flour to provide the necessary gas retention properties.  A strong first clear flour, high gluten flour or strong spring patent flour is often used.  This results in loaves with acceptable loaf volume and crumb texture.  The stronger the wheat flour, the higher the percentage of rye flour it will tolerate.  Because of their different extraction rates, there is a limit to the type and amount of rye flour that can be used in bread production without appreciable loss in perceived bread quality.  As a rule of thumb, white rye flours can be used in amounts up to 40%, the balance of the flour coming from wheat flour.  Medium rye flours can be used up to 30% and dark rye flours up to 20%.  These ranges should be used as guidelines only, since formulation and process play a significant role in determining the acceptable level of rye flour.

   Protein Range      Ash Range   Approx. Grade   Usage Level
White Rye Flour 7.0 – 9.0 0.65 – 0.80  Patent 0 – 40%
Medium Rye Flour 8.5 – 10.5 1.20 – 1.40  Straight 0 – 30%
Dark Rye Flour 13.0 – 15.0 2.25 – 2.55  Clear 0 – 20%
Rye Meal 9.0 – 11.0 1.35 – 1.75  Whole Grain 0 – 50%

Because baking is both a science and an art, incorporating rye flour or rye meal into your bakery products will require knowledge and experimentation.  There are no concrete rules, but hopefully this information and guideline will point you in the right direction.  For additional assistance, contact your local flour sales or technical service representative.  And the next time your waitress asks you if you want wheat or white toast, tell her, “Make mine rye.”

“Why Not Rye?” by David Kovacic first appeared as an article in Baking Buyer, September, 2011.

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