Flour contains five basic organic building blocks: proteins, starch, sugar, oil and enzymes. Sugar and starch are the yeast’s basic foods. Oil is in the wheat germ providing energy for the sprouting wheat. The wheat germ remains in whole wheat flour but the milling process removes it to make white flour which is free of oil. Enzymes are very minor constituents of flour.
There are many proteins in flour that are its main ingredients. Only two are important to develop the bread structure-gliadin and glutenin. These two proteins become gluten when you add water, but that is not enough for developing bread dough.
In order to form a proper structural framework that becomes bread, gluten must be developed by kneading. Kneading lengthens the gluten molecules so they can produce a firm, continuous structure. Gluten then becomes a rubbery, elastic chemical that forms a network in the dough.
Bakers know that the rougher they are with the dough, the faster and better the gluten develops. What kneading does is unfold and align the randomly oriented and twisted gluten molecules. Continued kneading lines the molecules up into parallel sheets that trap the carbon dioxide, and the air holes you see in your baked bread were all these trapped bubbles. When these sheets develop to the maximum extent, the dough changes its appearance from a gooey, sticky mass to a smooth, elastic, somewhat stiff ball that holds its shape. Fully developed dough remembers its former shape.
When you gently dent it with a finger, it slowly springs back like a balloon. (Some bakers say that a developed dough should feel like your earlobes.) The flour you use to make bread must have high enough protein content to develop gluten sheets in the dough. Flours range from soft to hard, terms that describe the starch content.
The more the starch, the less the protein. Soft flours are high in starch, low in protein, hard flours the opposite. For bread you want the high-protein hard flours. For general baking purposes, flour mills blend various types of flours to produce a single flour suitable for most household cooking and bakingpurposes. This compromise product is our all-purpose flour.
You can use it for bread baking but you don’t get the best, highest-rising breads with it. Commercial bakers are careful to use the optimum flour for every type of baking, but home bakers have less choice available. Bread flour is now on most grocery store shelves, but should you not have it in your community, you have a couple of options.
Ask at the local bakery if they will order an extra 50-pound bag of hard-wheat bread flour the next time they re-order their supply. If the baker is honest, the price is very reasonable, and 50 pounds (23 kg) of flour produces 45 to 50 loaves of bread. Baking two loaves at a time, that is not an unreasonable amount to store. Flour has a long shelflife if you keep it well covered in bins in a fairly cool, dry place, out of reach of tiny bugs and insects.
Your other choice is to buy all-purpose flour and add gluten flour to up the protein content. Gluten flour is wheat flour from which they remove most of the starch, leaving behind a concentration of gluten proteins. You can often find it in bulk at health and natural food stores.
It is costly but you need very little to make a good bread flour blend (5 percent gluten and 95 percent allpurpose flour). A loaf that calls for 3 cups of flour needs only 3 tablespoons of gluten flour. One of the baking tests I conducted for this post was baking three identical breads with three different flours: hard-wheat bread flour, all-purpose flour and all-purpose flour with 5 percentgluten flour. All three breads tasted the same, but the difference in the loaves was clearly visible.
The loaf I made with bread flour rose the most and held its shape the best when baking freeform on a baking sheet. The loaf I made with all-purpose flour plus gluten flour held its shape less well. It flattened a little and had a somewhat heavier texture. The all-purpose flour loaf flattened clearly during the last rising and baking, and the air holes were much finer than in the other two loaves.
Modern flours need no sifting before mixing them into bread dough. You can measure flour directly from the bin to the mixing bowl or on your work surface. It is always surprising to see in a new cookbook that the author still starts bread baking with the familiar, “sift dry ingredients into a bowl.”
Sifting is still a good idea if you have several dry ingredients that need mixing, as in quick breads. For yeast breads with few ingredients, forget about sifting.
Another misconception is exact measurements. A reasonable accuracy is fine, but you don’t need to draw a knife over the cup of flour. Yeast, salt and flavorings need to be exact in measurement. You don’t need to be quite so careful with the flour and water.