Straight Grade Flour
What is Straight Grade Flour?
After wheat is milled, all the flour streams minus the bran and germ are used to compose straight grade flour. It is mainly milled from the endosperm of wheat, with some particles of bran and germ that cling too tightly to the endosperm and cannot be removed during milling.
Straight grade flour is used to make patent and clear flour in the United States.
Straight grade flour has 12.9% protein, 1.17% oil, 0.4% ash, trace fiber, 70.9% starch, 0.7 ug/g thiamin, 0.7 ug/g riboflavin, 8.5 ug/g niacin, 1.42 mg/g iron, 2.2 mg/g sodium, 83 mg/g potassium, 12.9 mg/g calcium, 27.2 mg/g magnesium, 0.18 mg/g copper, 1.17 mg/g zinc, 98 mg/g total phosphorus, 30.4 mg/g phytate phosphorus, 48.4 mg/g chlorine.1
The American Association of Cereal Chemists International (AACC International) has the standard method for producing straight grade flour, the approved method 26-21.02, 26-31.01 or 26-50.01.2 Figure 1 shows the relation between whole wheat flour, straight grade flour, patent flour and clear flour (low grade flour). Straight grade flour is the whole wheat flour minus bran and germ. It is around 70 to 75 percent of whole wheat flour.1 French bakers use straight grade flour in their bread making while North Americans and the British generally don’t.3
Straight grade flour is sifted into other grades of flour. The straight grade flour is passed along a roller over different sieves. Different grades fall through the appropriate sieve along the roller. United States Department of Agriculture (USDA) listed the milling formulas, including the flour yield and baking quality score for soft wheat.4
Patent flour is classified into five categories, depending on the amount of straight grade flour it obtains:
- Extra short or fancy patent flour contains 40 to 60 percent straight grade flour. It is made from soft wheat and it is used for cake flours.
- First patent flour contains 60 to 70 percent straight grade flour. It is also made from soft wheat and it is used for cake flours.
- Short patent flour contains 70 to 80 percent straight grade flour. It is made from hard wheat. It is the most highly recommended commercially milled for bread baking.
- Medium patent flour contains 80 to 90 percent straight grade flour. It is also excellent for bread baking.
- Long patent flour contains 90 to 95 percent straight grade flour and it is good for bread baking.
Clear flour is graded into three categories:
- Fancy clear flour is milled from soft wheat. It is used to make pastry flour.
- First clear flour is milled from hard wheat. It is often blended by the baker with low-gluten flours to lighten the texture of breads such as rye or whole-wheat yet maintain the deep color desirable in such breads
- Second clear flour has a very high ash content and it is very dark. It is not generally used for food.
- Hoseney, R. Carl., and Jan A. Delcour. “Chapter 8: Dry Milling.” Principles of Cereal Science and Technology. St. Paul, MN, USA: American Association of Cereal Chemists, 2010. 129-30. Print.
- AACC International. “AACC International Approved Methods – Experimental Milling.” AACC International Approved Methods – Table of Contents. N.p., 2013.
- “Flour Grades.” CooksInfo.com. N.p., 12 Jan. 2010.
- USDA Agricultural Research Service. “Milling Formulas.” Milling Formulas: USDA ARS. N.p., 9 Sept. 2016.