Milling specifications

by Jeff Gwirtz
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This article is a summary of a presentation titled, “Flour Specification Comparisons” presented at the First Eurasian Regional IAOM Conference, held at the Marmara Hotel Istanbul, Turkey, Nov. 10-13, 2006. The new district encompasses milling professionals from European countries, focusing on Central and Eastern Europe and the former Soviet Union.

Meeting flour specifications is a daily challenge for millers in all parts of the world. While a government standard might serve as a basis for flour milling standards, in most cases the customer’s demand and specifications dictate what a mill produces.

The following is a comparison of the diverse parameters of several government flour specifications and special emphasis on detailed specifications reflecting the end-use properties of wheat flour.


The first specifications that millers encounter are wheat standards, which are often managed through specific governmental agencies acting with or without industry or “stakeholder” inputs or comments.

These standards tend to be very generic in nature and often consider factors that are more easily managed at the grain’s point of entry into the marketing system from the producer. Changes in grading factors are not typically embraced by millers, since they often result in additional training, expense and physical delays in the unloading and binning process.

As countries develop more open grain trading and marketing systems, it becomes increasingly important to develop these standards with stakeholder  input to maintain competitiveness and viability in the marketplace.

Governmental systems may have official grading standards that can be applied in the field by relatively untrained personal. Official grades conducted by trained and licensed personnel are more costly and time consuming.

In the U.S., grain is evaluated at receipt, and if a conflict exists between the buyer and seller, the conflict is generally resolved between the disputing parties. When an agreement cannot be reached on the grain quality with respect to grading standards and the contract, the parties may request an “official grade” in order to resolve the dispute.

Table I  (page 66)   presents the Wheat Grading Standards used in the U.S. As practitioners in the grain trade, milling and processing industries will readily note, there are many other factors that influence the quality characteristics of the wheat for its end-use application. The reality is the point of entry could not afford to run a complete battery of tests. Many of the tests would be of limited or no value for specific end-product manufacture.

Table II (above) lists characteristics of the six major classes of wheat in the U.S. These classes have different milling and flour characteristics that are used for specific end products.

U.S. Wheat Associates and other wheat marketing associations recognize the importance of these milling characteristics. In addition to reporting wheat grading characteristics, as shown in Table II, other quality factors are also reported including:

• Wheat non-grade characteristics;

• Wheat flour and semolina characteristics;

• Wheat flour and semolina dough characteristics;

• Wheat flour baking or semolina processing characteristics.

It is important to understand that such information is the average of samples taken and that specific needs and requirements should be negotiated between the buyer and seller.


Once the wheat is milled, the next specifications millers must deal with are for flour. In some countries, these may be established by law. However, like wheat grading standards, they may not completely describe properties from an end-use perspective. In the U.S., there is a Code of Federal Regulations that contains some standards of identity for grain flours and related products under Title 21 — Food and Drugs, Part 137 — Cereal Flours and Related Products.

The standards generally describe the  physical nature of the product, materials that may be added at specific levels and how test evaluations are to be conducted. Table III (below) shows an example of Flour and Enriched Flour Standards of Identity.

Flour, white flour, wheat flour and plain flour are prepared by grinding and bolting cleaned wheat other than durum wheat and red durum wheat. To compensate for any natural deficiency of enzymes, malted wheat, malted wheat flour, malted barley flour or any combination of two or more of these may be used, but the quantity of malted barley flour used must not be more than 0.75%.

Harmless preparations of alpha-amylase obtained from Aspergillus oryzae, alone or in a safe and suitable carrier, also may be used.

Enriched flour conforms to the definition and standard of identity, and it is subject to the requirements for label statement of ingredients, prescribed for flour by Sec. 137.105, except that:

(a) It contains in each pound 2.9 milligrams (mg) of thiamin, 1.8 mg of riboflavin, 24 mg of niacin, 0.7 mg of folic acid, and 20 mg of iron.

(b) It may contain added calcium in such quantity that the total calcium content is 960 mg per pound. Enriched flour may be acidified with monocalcium phosphate within the limits prescribed by Sec. 137.175 for phosphated flour. But if insufficient additional calcium is present to meet the 960 milligram level, no claim may be made on the label for calcium as a nutrient.

(c) The requirement of paragraphs (a) and (b) of this section will be deemed to have been met if reasonable overages of the vitamins and minerals, within the limits of good manufacturing practice, are present to ensure that the required levels of the vitamins and minerals are maintained throughout the expected shelf life of the food under customary conditions of distribution and storage.

Besides the standard of identity, there may be other regulations or laws that are controlled by various governmental agencies involved in the food supply chain. Specifically, there is a matter of natural or unavoidable defects in food, including those that present health hazards such as pesticide residues and other production and storage related materials.

The following are examples of levels of natural or unavoidable defects in wheat flour that present no health hazards for humans:

• Insect Filth (AOAC 972.32): Average of 75 or more insect fragments per 50 grams (g).

• Rodent Filth (AOAC 972.32): Average of 1 or more rodent hairs per 50 g.

• Defect Source: Insect fragments from pre-harvest, post-harvest or processing insect infestation, and rodent hair from post-harvest or processing contamination with animal hair or excreta.

Although these levels do not present a health hazard for humans, it can present a major problem for end-users from an aesthetic standpoint.

As with the grain grading standards, flour standards developed by governmental entities, even with stakeholder input, provide general guidance for product characteristics and little in the way of identifying characteristics for end-use application. The standards  do represent a common point of entry with respect to minimum-level expectations for the product in question. Further specification refinement is still required for the system to work in respect to delivering a final product to the consumer that meets their performance expectations.

Table IV (above), developed by former Kansas State University professor Marv Willyard, shows typical standards for flours used in manufacturing of various products.


As new decentralized governments are being formed and the milling industry adapts to more of a free market orientation, a greater awareness of customer needs will be necessary to maintain viability in the marketplace.

Rather than accepting available wheat and delivering a standard flour grade once identified by the government or agency, bakers will have choices. Flour will be produced according to the demands of the customer and lack of uniformity will not be accepted.

Grain traders, millers, and bakers in these countries are becoming more stakeholder than spectator, and it is important that they become active participants in the process of learning about specific needs in their countries or marketplace. The customer will determine your success or failure in the marketplace.

Dr. Jeff Gwirtz is a tenured associate professor in the Department of Grain and Science at Kansas State University. Gwirtz is also chief executive officer of JAG Services Inc., a consulting company serving the grain and milling industries. He can be reached by e-mail at .