ZT Flour Basic
Gluten
When the cook adds water to flour and stirs, two proteins in the flour (glutenin and gliadin) grab water and each other to form elastic sheets of gluten. Different flours have different amounts of these two gluten-forming proteins and, accordingly, absorb different amounts of water and form different amounts of gluten.
- Different in Water Absorption
How many of these two proteins a flour contains determines how much water it absorbs and how much gluten it forms. Some cooks have blamed this difference in absorption on humidity, which actually makes only a minute difference compared to protein content.
The difference in water absorption can be major. For example, 2 cups of high protein bread flour absorb 1 cup of water to form a soft, sticky dough. However, 2 cups of low-protein Southern flour or cake flour and 1 cup water make a dough that is between a thick soup and cottage cheese consistency. It can take almost ½ cup more low-protein flour to get the same consistency dough as with the high-protein flour. This means that even a small recipe with 2 cups of flour can be off by ½ cup! This is a difference of 25%; commercial recipes with 20 pounds of flour could be off by 5 pounds.
Cooks are constantly faced with this problem. The person writing the recipe used one kind of flour and the person following the recipe uses another. You need to realize that even though you follow a crecipe exactly, your dough may be very different from the dough that you are supposed to get with that recipe.
Many times in baking, a cook has to adjust-add more flour or more water to get a dough to the right consistency.
- Different in Amount of Gluten Formed
Different flours have different amounts of the two gluten-forming proteins and thus form different amounts of gluten.
Which Flours Have More or Less Gluten-Forming Proteins?
Hard spring wheats grown in colder climates are usually high in protein and make high-protein flour, outstanding for yeast breads. Soft winter wheats, grown in moderate climates where the ground never freezes to a depth greater than about 10”, have much less glutenin and gliadin. A few brands of flour are labeled with the kind of wheat, but most are not.
Not only are different strains of wheat different, but flour from the same strain of wheat can vary. Many things – soil, temperature, rainfall, maturity at harvest – influence protein content.
The milling process is a major determinant of the protein content of flour. When flour is milled, wheat kernels are cleaned and tempered )soaked in water), then crushed and the germ and bran removed. The endosperm (main central portion of the kernel) goes through one set of rollers and sifters after another, the these grind, sift, and separate flour into fractions called streams. There may be as many as eighty streams in this separation process. Just as winemakers blend juices from different vineyards to make fine wines, millers blend flour from different streams to make flours for different purposes. For a bread flour, a miller includes a lot of flour from the high-protein streams; for a low-protein, he uses the high-starch streams.
- All-Purpose!
Millers in Northern states, which have an abundance of high-protein flour, blend their all-purpose – particularly their unbleached all-purpose – high in protein (13 grams per cup) for their customers who have made fine yeast breads with these flours form many years. The customers of millers in Southern states specialized in biscuits, cakes, and pie crusts and are accustomed to low-protein flour (8-9 grams per cup) from soft winter wheat. So Southern millers blend a low-protein flour. Actually, all-purpose flour can ranger from more than 13 grams protein per cup down to about 8 grams per cup. Essentially, flour labeled “all-purpose” can be anything!
High-Protein/Low-Protein: How Can You Tell?
The Food and Drug Administration requires that flour be within 1 gram of the protein content stated on the bag. Previously, flour was labeled by 1-cup portions. Bread flour was labeled 14 grabs per cup, unbleached 12 to 13 grams per cup, national brand all-purpose 12 grams per cup, Southern all-purpose 9 grams per cup, and cake four 8 grams per cup. It was easy to tell those labeled 13 to 14 grams were high protein; those labeled below 10 grams per up were low protein.
Unfortunately, the portion amount for the new regulations is ¼ cup and nearly every flour on the market is labeled 3 grams per ¼ cup. This means the flour can be from about 2 to 4 grams of protein per ¼ cup. The flour in the bag labeled 3 grams per ¼ cup can really have from about 8 grams per cup to 16 grams per cup. Low-protein Southern flour is now labeled 3 grams per ¼ cup, and high-protein bread flour also may be labeled 3 grams per ¼ cup, and tell absolutely nothing from the label about the specific protein content of the flour that is important for cooking.
You know that bread flour is excellent for breads. You know that cake flour is excellent for cakes. And millers have traditionally always made unbleached flour high in protein, so you know that most unbleached flours will make light yeast breads. Self-rising flour is low in protein, but it you need a low-protein flour without leavening, you will need to used a Southern low-protein flour, a pastry flour, or to mix one-third cake flour with two-thirds national brand bleached all-purpose.
Best Flour for Yeast Breads?
Knowing that the higher the protein in plain white flour, the more gluten is formed, I wanted nothing but hard spring wheat – the highest-protein flour to make breads.
I had to completely drop everything that I thought that I knew about flour and start all over. In the class that I took, Didier knew his students would believe in the very high-protein hard spring wheats. And he knew the only way that he could get us to change our minds was to show us side by side that his lower-protein flour milled from hard red winter wheat made a better baguette than our higher-protein hard spring wheat flour.
We made baguettes side by side, the same techniques, same times, same temperature. I had great confidence in my very high-protein hard spring wheat. I did not think Didier’s lower-protein hard red winter wheat could possibly make loaves with as great a volume as my higher protein flour.
I would never have believed it if I had not made the breads myself. The loaves with the lower-protein winter wheat were actually as high as or a breath higher than my beloved spring wheat! And then there was the taste. I could not believe how much more flavorful the winter wheat loaves were – an amazing difference in taste.
I knew that when you add water to flour and stir, two proteins in the flour grab the water and each other to form elastic sheets of gluten. And I vaguely knew that glutenin was responsible for gluten’s elasticity – its ability to spring back, and that gliadin influenced gluten’s extensibility – its ability to stretch. What I didn’t realize was how important this extensibility is for well-risen doughts.
Having a dough that will stretch is really important. I the gluten can stretch more and mort without tearing and letting the gases produced by yeast escape, you will be able to produce will-risen bread. I just needed to realize that the plastic properties of gluten consist of three parts: strength, extensibility, and elasticity.
This extensibility is dependent on the variety and origin of the wheat, on other ingredients in the dough, and on techniques.
There Is Gluten and There Is Gluten
I was a research chemist for the Vanderbilt Medical School. As a chemist, years ago when I was studying bread, I had a hard time understanding gluten. I wanted a formula – like x number of molecules of glutenin plus x number of molecules of giadin plus x number of molecules of water equal x number of molecules of gluten. Gluten doesn’t work that way – no orderly formula. It is just a mess of stuff linked together.
Gluten can have totally different amounts of gluenini and gliadin depending on the variety and growing conditions of the wheat that the flour is made from. So gluten can have more gliadin and be more extensible or it can have more glutenin and be more elastic. This is why flour from hard re winter wheat makes wonderful breads. This flour, with the proper techniques, is wonderfully extensible and can make loaves that are as high as or higher than very high-protein flours. And properly handled breads made with this flour can have wonderful flavors.
Types of Wheat
Types of wheat – winter wheat, spring wheat. Hard wheat, soft wheat, durum, spelt, kamut, einkorn, emmer, and on and on. In general, hard wheats have more protein than soft wheats, and spring wheats have more protein than winter wheats. The hard red winter wheat that I have used so much in this section is a medium-high protein, about 11.7% protein.
My other favorite wheat is durum (semolina). I just love the taste of durum flour or its slightly coarser grind, semolina. You don not get as much gluten development as you would with hard red winter wheats or spring wheats, but you can make a wonder ful loaf with a mix of semolina and unbleached flours.
From “BakeWise. The hows and whys of successful baking ” by Shirley O. Corriher
