All about flour

Flour




Flour is the items we are most questioned about. We contacted General Mills and were given the following information, we hope you find it helpful. If you are a culinary student you may notice that some of the terms may be a little different from culinary text books but the overall results are the same.



When we talk flour we are talking wheat flour. Because wheat is the most commonly distributed cereal grain in the world, a reference to flour is generally a reference to wheat flour. And just as flour is not "just flour", wheat is not "just wheat". So to better understand flour, we first need to understand wheat.



Wheat Categories



Wheat can be classified by three major categories: growing season, brand color and kernel hardness.



Growing Season-Winter vs. Spring



There are two distinct growing seasons for wheat. Winter wheat is planted in the fall, lies dormant during the winter months and is harvested during late spring to early summer. Winter wheat is grown in regions where the winters are mild. Winter wheat flours range between 10 and 12% protein and have medium gluten strength.











Spring wheat is planted in the spring and harvested during late summer. The production of spring wheat is concentrated in the northern Great Plain states where the winters are too cold for winter wheat to survive. Spring wheat flours range between 12 and 14% protein and have high gluten strength.



Bran Color-Red vs. White



The next category is bran color. The bran is the outer protective coating of the wheat kernel. Wheat can be classified as either red or white.



Kernel Hardness-Hard vs. Soft



The final classification is kernel hardness. This wheat characteristic has the greatest impact of all three on baking qualities of the flour produced. Hard wheat flours have a medium to high protein content and stronger gluten-forming proteins than sift wheat. hard wheat flours are used in yeast-raised goods such as breads, bagels, and pizza crusts. Soft wheat flours are low in protein and therefore low in gluten strength. Soft wheat flours are used for chemically leavened goods, such as cakes, cookies and biscuits.



Wheat Classes and Their Uses



These three categories are used to distinguish between the major wheat classifications. In the United States, their are six main classes of wheat. The quality characteristics vary between the wheat classes and determine the end-product usage. The six wheat classes and their uses are as follows:



Hard Red Winter, Hard Red Spring, Hard White are the first three and they are used for Breads and other yeast raised products.



Soft Red Winter, Soft White are used for Cakes, crackers, cookies and pastries.



Durum is used for Macaroni, noodles and other pastas.



Flour Milling



Now that we have an understanding of the different types of wheat available, we'll start our discussion on flour. The place to begin is at the mill where the flour is produced. The goal of the milling process is to separate as fully as possible the endosperm from the bran and the germ portion of the wheat kernel. The endosperm is then further reduced into a fine powder that we call flour. The amount of flour obtained from the wheat is known as the extraction. The actual proportion of endosperm to the total wheat kernel is about 83%, but true extraction rates run between 73 and 75%. The balance of the material from the wheat kernel, called mill feed, is sold off to the feed industry.



The Milling Process



Before the milling process begins, the wheat is cleaned and then tempered. Weed seeds, dirt and other foreign materials are removed by the brain cleaning equipment. In the tempering process, the moisture content of the wheat is increased to toughen the bran coat, assisting in the separation of the endosperm. The increased moisture also mellows the endosperm allowing for more efficient reduction into flour. In the mill, the wheat is sent through a system of corrugated steel grinding rolls and sifters. This process of grinding and sifting is repeated until all of the endosperm is removed and only the bran remains. The particles of endosperm are graded through the sifting process, according to size, and are sent to the appropriate part of the system for further reduction.



The reduction system consists of smooth steel rollers and sifters that reduce the endosperm particles into finished flour. Throughout this process the miller has the ability to collect or divert specific flour streams, which differ analytically, in order to produce specific finished flour.



Flour Analysis - Ash, an index of flour extraction



Ash is a measure of the mineral content of flour. The mineral content of the wheat kernel is concentrated in the bran layer. The objective of the miller is to separate the endosperm from the bran as completely as possible. Ash is a measure of the degree of endosperm separation from the bran during milling. The closer the miller gets to the bran layer, the higher the ash level becomes. Higher extraction will result in higher ash levels.



Protein - the framework of bread



Wheat flour is unique because it in the only cereal grain that possesses gluten-forming proteins. Gluten and protein are closely related, but not synonymous. When combined with water under mixing stress, the proteins in the flour will form what is called gluten. This gluten structure is responsible for providing extensibility, elasticity and gas-retaining properties to yeast-leavened baked goods. The quantity of the gluten is proportionate to the amount of protein in the flour. The amount of gluten will increase as the protein content increases.



Protein quality vs. quantity



To buy flour purely by a protein quantity will not necessarily guarantee baking performance. Protein quality is a key component and can be affected by many agronomic factors such as the amount of rainfall, fertilizer usage, temperature stress, etc. A quality miller is going to balance protein quantity with the appropriate quality testing to prepare the best flours available for specific baking needs.



Measuring Quality



Quality of flour is defined by its ability to consistently perform in the production of a finished baked good. The ultimate quality test is completed when the baker uses the flour. Bake test are completed based on the application that best suits the particular flour. Protein quality can be measured indirectly with the dough-testing devices such as the Farinograph. The Farinograph measures the resistance of a flour and water dough to mechanical mixing. This resistance is recorded as a curve on a graph. The Farinograph curve provides the miller with the useful information regarding the dough strength, mixing tolerance, and absorption (water holding) characteristics of a flour.



Flour Treatments - Bleaching makes the flour whiter



The term "bleaching" is a traditional baking industry term that describes the process of whitening.



Technically speaking, the carotenoid (yellow) pigments in the flour are oxidized to produce white flour. Oxidization will occur naturally, over time, with the exposure of flour to air. Historically, millers would age flour for several weeks to achieve white flour. This natural oxidation, however, was an irregular process requiring considerable time and space. Today, the bleaching process is accomplished by the use of chemical bleaching agents. Flours treated with these bleaching agents must be labeled as bleached flour.



Maturing - Strengthening of the flour



For hard wheat flour, the term maturing implies the strengthening of dough-forming properties, thus improving gas retention of the gluten. Common maturing agents include potassium bromate (used mainly in the midwest and the east) and ascorbic acid (used mainly in the west). Breads treated with these agents will generally exhibit increased loaf volume, finer grain and improved external characteristics.



Malting - addition of malted barley flour



Malted barley flour is added to hard wheat flours to assist yeast fermentation. During the dough-forming stage, malted barley flour provides specific enzyme activity that converts the starches in the wheat flour into simple sugars. These sugars are then available as a food source for the yeast to maintain proper fermentation activity. Malted barley flour also aids in proper crust browning.



Enrichment - addition of nutrients to the flour



Enriching replaces the vitamins and minerals lost during the milling process. The standard flour enrichment includes iron, the B vitamins: thiamin, riboflavin and niacin, and folic acid. The enrichment of flour has no effect on the baking performance or caloric value of flour.