There are several kinds of wheat flour available for sale with the most popular being enriched and bleached all-purpose flour. The differences between the flours comes down to the type of wheat, the parts of wheat included, the processing of the wheat, and any additives added to the flour. In this article, I'll examine each of these characteristics:
Protein content A certain type of protein called gluten (glutenin) is responsible for wheat flour's elastic properties. The more gluten in a flour makes it easier for the flour to build up a tough structure able to trap the waste gases of yeast during kneading as well as rise effectively during baking. Less gluten in a flour produces a lighter, less chewier texture such as those found in cakes. The exact amount of gluten in your flour depends on where it was milled and the variations in growth of the wheat crop.
The main wheat varieties grown in the United States are, in order of quantity grown and sold, hard red wheat, soft red wheat, durum and white. Hard red wheat is used to produce flour high in gluten content, while soft red wheat is used for flour low in gluten. Durum is milled to produce semolina flour used mainly for macaroni pastas. Semolina flour has the highest gluten content of all mass produced wheat flours. White wheat is produced in smaller quantities in the U.S. and makes low gluten flour.
High gluten flour and bread flour is produced from hard wheat. High gluten flour has a gluten percentage of about 12-14% while bread flour contains about 10-13% gluten. Both flours are almost completely made of hard wheat, but some high gluten flours are treated to reduce starch content, raising the gluten content to around 14%. These flours are generally used for making breads. High gluten flour is reserved for breads that are extra elastic such as bagels and pizza.
Cake flour is produced from soft wheat and is low in gluten content (8-10%). This flour is used for making delicate cakes. Baked goods made with cake flour has a tendency to crumble because of the low gluten content.
All purpose flour is made from a mixture of hard and soft wheats. The gluten content ranges from 9-12%. This is the most versatile flour because it can be used to make both cakes and breads. However, breads won't be as chewy and cakes won't be as tender as if you used bread or cake flour.
Pastry flour is also a mix of hard and soft wheat flours with an emphasis on soft. Generally, the gluten content is 9-10% and is often recommended for pie crusts.
Germ Whole wheat flour contains the germ (the embryo of the wheat kernel) and is more flavorful than regular all-purpose flour which does not include the germ. Because the germ is included, there are more nutrients as well as fiber and fat content in whole wheat flour. However, the flour should be stored in the refrigerator to prevent the germ oils from becoming rancid.
Processing Almost all the flour sold is steel ground meaning a large machine with steel hammers or rollers crushes and grinds the wheat kernels down. This is a very efficient means of producing flour, but the steel surfaces heat up with the high speed and volume of wheat being ground. This heat causes some of the vitamins in steel ground flour to be destroyed during the grinding process.
Alternatively, stone ground flour is produced by the relatively slow grinding of large stones together (with the wheat in the middle). This type of flour is harder to find and almost always leaves the germ intact producing whole wheat flour. There is no heat build up, so all the nutrients stay intact as the four is made.
Bleaching or aging is another process that differentiates flours. Bleached flours produce doughs that are less sticky and rise better than unbleached flours. Bleaching can be accomplished by aging the flour over time (the oxidation of the flour causes the yellow pigments to fade) or through a chemical means (usually using chlorine dioxide and potassium bromade to age the flour). The aging process removes some of the naturally occurring vitamin E present in wheat. The flour ends up uniformly white and has (generally) better baking properties.
The texture of the flour is determined by how much sifting (or bolting) is performed at the mill. The degree of sifting will result in a powdery flour or a coarse flour. Prior to packaging, most flours in the United States are also presifted. Presifted flour can be measured directly from the bag by stirring, measuring with a dry measuring cup, and leveled with a straight edge. Unsifted flour needs to be sifted prior to measuring (by volume). If unsifted flour is measured by weight, it should still be sifted prior to use in a recipe requiring sifted flour (assume all recipes require sifted flour).
Additives Enriched flour contain vitamins and nutrients that have been added to offset the loss from the grinding and aging of flour. Usually, niacin, riboflavin, thiamin and iron are added to flours that do not contain wheat germ. In addition vitamin E is often added to bleached wheat. Some brands will also contain additional vitamin A, C, and D.
Some bread flours will have a little bit of malted barley flour added to help yeast growth. In addition, potassium bromate may be included to lend strength and help the dough maintain the yeast gases.
The addition of baking powder and salt produces self-rising flour or leavened flour. When using self-rising flour, simply omit the baking powder and salt from the recipe (leave in any baking soda a recipe calls for).
Other names? Outside of the United States, different types of flour may have different names. For example, plain flour is often similar to all purpose flour. However, the regional differences that cause all-purpose flours to vary from U.S. state to state, also cause similar flours from other nations to differ slightly in property from those in the United States.
My mom has celiac disease, an allergy to gluten that she contracted while she was pregnant with my little brother. If she eats anything with gluten in it (wheat, barley, rye, or oats), the villi in her small intestine shrivel up and die, and she has gastrointestinal distress.
So I grew up in a house without much bread, cake, cookies, or pretty much anything else with wheat in it. We ate lots of rice and potatoes, and sometimes had interesting things like buckwheat or Pai Mai Fun rice noodles. It really broadened my food horizons, something I took for granted until I got to college and found out that most people would never try things that I found delicious because they hadn't been exposed to it.
Celiac disease affects about 1 in 133 people in the US. For more information, check out http://www.celiac.com/
Excellent article, I just had one thing to add. I mill my own grain at home and we also can get hard white wheat. I haven't found the soft red but I have hard red, hard white, and soft white, spelt, rye and kamut. I would like to get soft red because my father told me that that is what he grew when on the farm in Ohio growing up. I started milling my own flour when friends told me about it. It's a lot more nutritious and the fiber is easier on the system. I also found that I could use other grains that are less allergenic than wheat. I recently red about "diastatic malt" made from sprouting wheat and used in breadmaking. I am currently researching that topic.
St. Petersburg, Florida
Posted: Wed Oct 18, 2006 4:53 pm Post subject: Wheat Flour
Being an engineer, I love to be precise. I don't believe any flour contains gluten. Wheat flour contains two proteins, glutenin and gliadin. Gluten is not formed until water is added and you begin to stir the mixture. The proteins combine with water and with each other to form gluten. The more you stir, the more gluten is formed.
My friend avoid recipes that rely on convenience foods. Go back to the "from scratch" recipes the convenience food replaces. Learn to make the basic sauces and gravies often used in casseroles and soups. Look in a gluten-free cookbook or Lifeline for a similar recipe. Compare proportions, they are the key. Flour and other ingredients that act as thickeners are compared to the amount of liquids in the recipe.
Well have you people heard about the latest craze towards the protein foods? I am sure you people must have heard this, where the emphasis is on a no carbohydrate diet and everuthing that one has for food involves the protein. But then there are pros and cons of this diet, as we all know carbs are the main suppliers of energy in the human body. So I wonder what the others have to say regarding this.