Wheat flour comes in many different forms. First, let’s talk a bit about the wheat from which it originates.
The wheat berry has three basic parts: the endosperm, the germ and the bran. The germ is the embryonic plant, but is only about 2-3% of the total berry. The endosperm, which is about 75% of the berry, serves as food for the germ as it sprouts. The rest is the bran, which protects the tiny germ.
White flour is almost pure endosperm, whereas whole-wheat flour retains all three parts. As a result, white flour will keep for a long time at room temperature – probably a year or more. Whole-wheat flour, on the other hand, contains the oily germ, and that oil goes rancid at room temperature in just a couple of months. This is why so many people think that whole wheat bread tastes bitter; mostly likely, the bread they ate was made from rancid flour.
All-purpose or artisan flour: For most artisan white breads, bakers generally prefer all-purpose (AP) or so-called artisan flour. These flours typically have a protein percentage of 10.5% to 11.5% or so. King Arthur Flour’s regular AP flour is about 11.7%, so it’s on the very high end, while General Mill’s AP flours are about 10.5%. Most Southern brands of AP flours like White Lily are not good for making bread, because they have a low protein percentage and are also bleached, but are better suited to cakes and biscuits.
Bleached flour will produce bread if it has a high enough protein percentage, but it will not have the same golden color or rich flavor of unbleached flour.
King Arthur Flour’s Organic Artisan Flour and Giusto’s Baker’s Choice are favorites among amateur artisan bakers. They’re about 11.3% protein and perform beautifully, striking a nice balance between rise and flavor. However, these preferences aside, one can bake very good bread from basically any unbleached all-purpose flour one can buy at the grocery store.
Bread flour: White bread flour is typically between 11.5% and 12.5% protein. Some brands, such as King Arthur Flour, are very strong with close to 13% protein, whereas others are closer to All-Purpose flour. Bread flour is good to use when making bread with a high percentage of rye flour or a lot of goodies like nuts, seeds, cooked grains or dried fruits. It produces a spectacular rise, but without additions, some bakers find that bread made from this flour is a bit tough and somewhat lacking in flavor compared to all-purpose flour.
Whole wheat bread flour: Not all whole wheat flours are the same. The bran in whole-wheat flour punctures the gluten web which traps gas, so it won’t rise quite as high as most white flours. As a result, you want to find a whole-wheat flour with as high a protein percentage as possible. The bran also contains protein, so look for a flour with at least 14% protein. You’ll also want to make sure that it’s fresh becausewhole wheat flour goes rancid after just a couple of months at room temperature because it retains the oily germ. King Arthur Flour and Giusto’s are both high-quality brands.
You’ll want to store whole-wheat flours in the freezer so that they’ll keep longer.
White whole wheat bread flour: Traditionally, whole wheat bread flour is made from hard red winter wheat or hard red spring wheat. However, in recent years, a variety of hard white wheat flour has come on the market that is strong enough to make bread. It lacks the tannins that give the red wheat its color and, for some people, a bitter flavor. Some folks really like it, finding that it mimics the taste of white flour and is less bitter than traditional whole wheat flour; others find it has a waxy texture that’s unappealing. But white whole wheat flour is certainly worth trying to see what you think.
Whole wheat pastry flour: Perfect for all quick breads, this flour is made almost exclusively from soft white winter wheat, and has a low percentage of protein. So long as you increase the liquid in the recipe a bit, you can substitute it for white flour in nearly all quick breads, and hardly anyone will be able to tell the difference. Really!
While wheat flour predominates in the breads of southern Europe and the UK, rye flour plays a more important role in the breads of northern and eastern Europe. This is due to rye's superior ability to grow in the poorer soils and cooler, wetter climates of those regions.
Chemical differences in the proteins and enzymes found in rye present differences in how rye flour behaves when mixed with water to make dough, and these differences impact the use of pre-ferments, mixing, fermentation and baking when there is more rye than wheat flour in the dough.
There are a number of different types of rye products available. They vary in how much of the rye berry is included, just as whole wheat differs from white wheat flour. They also differ in how finely ground the rye is.
There are breads made with 100% rye flour, but many other breads are made with lesser percentages. The influence of rye flour on dough handling and on the resulting taste and texture of the bread varies according to the proportion of rye used.
Chemical differences in rye
Gluten is the primary protein found in wheat, and the methods of mixing dough made with wheat flour center on their impact on gluten development and structure. Gluten forms the framework of cells that trap the carbon dioxide generated by fermentation of sugar by yeast. This trapping generates the expansion of the dough (rising) and ultimately the texture of the bread's crumb.
Rye contains much less gluten than wheat, and the gluten rye contains is of poor quality when it comes to trapping air bubbles. Consequently, breads made with mostly rye flour do not expand as much as those made with mostly wheat flour. The crumb of breads in which rye predominates tends to be dense with smaller holes. On the other hand, rye has more free sugars than wheat, so rye dough ferments faster.
Rye contains a group of important complex sugars called “pentosans.” These are present in other grains, but rye has more of this substance. Pentosans are important to the baker for several reasons. They compete with the proteins that make gluten for water, and water is the substance that leads the proteins to combine to form gluten. This means that rye doughs often require a higher proportion of water than doughs in which wheat predominates. Pentosans break apart easily during mixing, and their fragments result in a stickier dough. Because of this, rye doughs require gentler and, usually, briefer mixing than wheat doughs.
Rye is higher in the enzymes (amylases) that break down starch into sugars. Starch is needed to form the structure of the crumb, and if too much starch is split up, the texture of the bread suffers and becomes gummy. Traditionally, this is prevented by acidifying the rye dough, which slows down the action of amylases. This is why breads with a high percentage of rye flour are made with rye sour (rye-based sourdough starter), even if commercial yeast is added.
Acidification of rye dough has other nutritional advantages specific to rye bread which may also be of interest to the home baker, as well as the advantages that also apply to wheat-based sourdoughs.
Rye products used in baking bread
Whole rye berries may be used in bread, after soaking, to contribute flavor and texture. Rye berries are also used after breaking them into smaller pieces in the form of rye chops, cracked rye, rye flakes, and so forth.
The rye flours you may find include the following:
In Europe, especially Northern Europe, a much wider range of rye flours is available, encompassing different grinds as well as a variety of percentages of bran and germ.
Rye flour that contains the oily germ (pumpernickel, dark and medium) spoils very quickly, so try to buy the freshest possible and store it in the freezer.
Rye flour used together with wheat flour
A small amount of rye – 5-10% of the total flour by weight – has a definite effect on the flavor of the bread. The distinctive flavor of the rye itself may not be noticed, yet the bread's overall flavor seems better. This may be due to the action of the amylases in rye releasing more sugars. This small addition of rye is what defines a French pain de campagne. These breads are often sourdoughs, but the rye may be added with the rest of the flour rather than as a rye sour. There is so little rye in the dough, that it's behavior during mixing and fermentation and its texture when baked may be indistinguishable from a purely wheat bread.
Breads containing up to 40% rye flour are usually called “rye bread.” Jewish Sour Rye (New York Rye, Deli Rye) is a familiar example. The rye flour is in a large enough proportion so that it is advisable to add all or most of it as a rye sour. There is enough rye so that a distinct rye flavor is tasted. However, there is enough wheat flour to provide gluten to form the kind of crumb we associate with wheat breads.
The dough in these breads will feel different during mixing, tending to be stickier. The temptation is to add more flour, but this should be resisted. When hand kneading sticky rye doughs, using rapid, light strokes - minimizing the time your hands are in contact with the dough - decreases the amount of dough that will stick to your hands. You may also find that wetting your hands with water or lightly oiling them helps.
Breads with over 50% rye flour are another story. All the special considerations due to the chemical differences in rye become more important as the proportion of rye increases. Typically, these breads have a short bulk rise and, once baked, should be allowed to rest for several hours before slicing, so the crumb can set up properly. In the case of breads with 70% rye or more, a rest of 24 hours, even up to a couple of days, may be required.
Pastry flour: Pastry flour is perfect for making quick breads like muffins, banana bread, waffles, and pancakes. Its protein percentage is usually about 6% to 8%.
High-gluten flour: This flour is typically only available to commercial bakers or via mail order from places like King Arthur Flour. Its protein level is usually greater than 14%. It’s used in bagels (it gives them their tasty chewy texture) and breads with a high percentage of rye.
Fancy durum flour. Also known as semonlina flour (though ground finer) or pasta flour, durum flour is made from durum wheat. Though high in protein, durum flour does not contain enough gluten to make good bread unless mixed in with regular wheat flour.
00 flour. 00 is an Italian designation for a type of flour commonly used in pizza crust. It is softer (lower in protein) than American bread or all purpose flour.
Spelt flour: Spelt, which is also known as farro, is an ancient grain that is a cousin to wheat. It contains enough gluten to make a light loaf of bread, but absorbs less water than wheat, and so requires a lower hydration. The gluten is also somewhat less resiliant than that of wheat, and, as such, one needs to be careful when using a mixer, as it's easy to over-develop.