RYE BREAD INGREDIENTS A. Rye Flour

It is generally known that rye flour does not contain the type of protein system, characteristic of wheat flour, that leads to gluten formation during mixing. However, this does not mean, that the differences between various types of rye flour are without significance.

Rye flours may be classified into four general types: (1) white or patent grade; (2) medium or straight grade; (3) dark grade; and (4) meal or whole grain.

White or patent rye flour is a product that is essentially white and relatively bland. It is composed almost entirely of the endosperm portion of the rye grain, i.e., mainly starch, which exerts a minimal loaf volume depressing effect. It finds extensive use in the production of Jewish-type rye bread. When used in rye bread production, it can exceed 40% in the total flour blend without noticeably reducing the loaf volume.

Medium or straight grade rye flour comprises all flour that can be milled from the rye kernel, excluding, of course, the bran and germ portions, and corresponds in grade to the straight flour of wheat milling. It possesses a somewhat distinctive and characteristic rye flavor. It can be used in relatively large proportions in rye bread production and gives good results.

Up to 30% of the total lbs of flour may be used to produce an excellent and flavorful loaf of rye bread with a highly acceptable volume.

Dark grade rye flour represents the coarser portion of a straight rye flour that remains after the white or patent flour has been removed. It is distinctly a lower grade flour, relatively dark and with a pronounced rye flavor. It is well suited for the production of Pumpernickel-type rye breads, imparting to them their dense grain and full flavor, but when used in rye bread its proportion must be held to below 15% in the total flour blend;

otherwise loaf volume will suffer excessively. In general, the dark flours possess higher absorption and moisture retention capacities than do the light grades of rye flour.

Rye meal, also known as Pumpernickel flour, is obtained by grinding of whole rye kernel. It is available in a range of granulations, depending on the degree of grinding. The more finely ground grades are readily adapted to rye bread production, with the proportions used corresponding essentially to those of the dark rye flour.

By judiciously blending various proportions of these different rye flours, the baker is able to produce rye breads of distinctive and unique taste appeal (Meyer, 1965; Lorenz, 1982, 1987). Product specifications of rye flours are given inTable 1.

Some mills will produce other grades intermediate between the three grades given above. An extra dark rye is sometimes made that will have an ash content as high as 3.0%. Most of the major mills market rye blends that are made from a mixture of strong spring wheat clears and rye. These will roughly follow a pattern of 70% clear and 30% medium rye, 80% clear and 20% dark rye, and 50% clear and 50% white rye. Other blends may also be custom blended to suit a customer’s own market need and the rye bread he or she desires. The characteristic rye flavor increases as the ash increases and

the color deepens; therefore, if one wishes to impart a greater rye flavor to a product, the darker rye flours should be used (Schmalz, 1970).

Entire rye grain products consist of rye meals (sometimes referred to as rye chops and sometimes as Pumpernickel), flattened rye grain (referred to as flaked rye), and sharply cut rye (called steel cut cracked rye). There is no standardization either in the terminology or the granulation of these above products, and a great deal of confusion exists in the trade in communicating between buyer and seller for the correct designation of the desired product.

Usually, the buyer submits a sample to the miller for matching to get the desired product. A great service could be rendered to the rye milling industry if the manufacturers would agree on standards of granulation and nomenclature.

In the area of rye meals, which are analogous to whole wheat, granulations from extrafine to extracoarse and rye flakes from thick to thin are available. The meals are produced on a very short system mill similar to a whole wheat mill (Schmalz, 1970). Uses of the different rye flours in various rye breads are indicated inTable 2.

While differences in color, in dependence on extraction rates, are readily apparent in rye flours, a property of equal importance to ultimate bread quality, but one that is less easily detected and evaluated, is freshness.

It is axiomatic of rye flour that for any given grade the best product is the freshest, in contrast to white wheat flour where extended aging is frequently desirable and even necessary for optimum baking performance. Thus, Table 1 Basic Grades and Product Specification of Rye Flours

Moisture (%) Ash (%) Protein (%) Color White or light rye

flour 14.5 maximum 0.58–0.78 7.0–9.1 White

Dark rye flour 14.5 maximum 2.05–2.83 13.7–16.2 Dark Medium rye flour

(blends of above

2 grades) 14.5 maximum 1.11–1.39 10.1–12.8 Medium white Rye meals (may be

flaky, coarse, medium, fine,

extrafine) n.s. n.s. n.s. n.s.

Source: From Lorenz (1982, 1987).

n.s.—no specification.

regardless of the grades of rye flour a baker elects to use, he must make certain that the flour is fresh if he is to obtain a baked loaf of the desired flavor and keeping quality (Meyer, 1965).

B. Wheat Flour

As far as the wheat flour in rye bread production is concerned, a strong first clear is generally recommended. The blending of wheat and rye flours is necessary to produce a loaf of the desired volume since rye flour lacks the gluten capable of retaining the gases formed during fermentation. Strong patent and second clear flours can be used successfully in a blend. The stronger the wheat flour, the greater the percentage of rye flour that can be used without a reduction in loaf volume.

Table 2 Basic Rye Flours: Types and Uses

Rye flour type Suggested uses

White rye Jewish and other rye breads Dusting flour (bench type) Light Swedish rye bread

Medium rye Bohemian, Polish, and Russian rye breads For blending with other rye flours In American-type rye breads Medium Swedish rye breads Base for rye sours

Dark rye American rye breads (lower levels than medium rye flour)

Dark, heavy German rye breads

Pumpernickel breads—for flavor and color Swedish rye bread

Base for stronger rye sours

Rye meal In various types of pumpernickel bread (various granulations) For dusting in hearth rye breads

Cracked rye Used in either white bread dough or rye to make a specialty cracked rye bread (should be soaked before adding to dough)

Rye flakes

(flat, rolled whole rye)

For blending with meal and rye flour in pumpernickel bread

In crisp, flat Swedish rye bread In rye crisp wafers

Source: From Gordon (1970) and Lorenz (1987).

C. Various Other Ingredients

The typical rye dough contains, in addition to blends of wheat and rye flours, a number of other ingredients in smaller amount (Meyer, 1965;

Lorenz, 1987).

1. Salt

Salt is used at slightly higher levels in most rye breads than normally used for white bread. Rye flour is more fermentable than wheat flour. Therefore, salt, plays a more significant role as a fermentation regulator. Salt also greatly enhances the true rye flavor of rye breads.

2. Malt

Malt is an optional ingredient. It stimulates fermentation and imparts a desirable color and a good sheen to the crust. If excessive amounts are used, very sticky doughs may result and the bread could have a dense, gummy crumb.

3. Shortening

Shortening plays an important role in rye bread production, especially if all of the makeup is done mechanically. It also helps to improve keeping quality, crust tenderness, and slicing operation. Excessive gumming and smearing of slicer blades can be minimized by an adequate level of fat in the formulation.

4. Yeast Food

Requirements for yeast food in rye doughs are somewhat lower than in white bread doughs, since one of its principle functions is to stimulate fermentation activity and this is already adequate in rye doughs.

5. Sugar

Sugar is used to impart sweetness and improve crust color. Sucrose, brown sugar, or molasses may be used.

6. Milk

Nonfat dry milk or buttermilk solids may be used to improve texture, crust and crumb color, slicing performance, and nutritional value (Silva, 1956).

7. Yeast

Yeast is the primary leavening agent in mixed wheat–rye breads. The percentage used will depend on the amount of rye flour in the formulation and the desired duration of fermentation.