What follows is adapted from various sources, principally
Jeffrey Hamelman, “Bread,” pages 32-48
Raymond Calvel, “The Taste of Bread,” pages 7-14
Carol Field, “The Italian Baker” pages 34-39
All the books cited in this article are available from Amazon — Please use the link on the right side to order them.
Types of wheat.
Farmers grow six types of wheat.
1. Hard red winter wheat
2. Hard red spring wheat
3. Hard white winter wheat
4. Durum wheat
5. Soft white winter wheat
6. Soft white spring wheat
The soft wheats are not used in bread production; they are lower in the necessary proteins and higher in starch than the others, and are reserved for the production of pastries, cakes and the like. We will limit our discussion to the first four wheats.
Winter and spring in the description refers to when the seeds are planted. A winter wheat is planted in the fall, starts to grow, undergoes a period of dormancy during the winter, continues growing in the spring as the weather warms and is harvested in May to July. A spring wheat is planted in the spring and grows until the late summer or fall, when it is harvested. As between the two, spring wheat usually has the higher protein content, while winter wheat has a higher quality protein, one that appears to be better suited for artisan bread baking.
The terms red and white refer to the color of the grain itself. A white wheat has a recessive gene for bran color, which makes it appear whiter than a red wheat. White wheat is also a bit milder in taste than red wheat. The “white whole wheat” flour in the store is made from this white wheat, even though the bran content of the flour is high enough to qualify it as whole wheat.
Durum wheat is very high in protein, but is used mostly for pasta, although it is used in a few specialty breads.
The Wheat Berry
The wheat grain is termed the wheat berry. It is composed of a hard shell, the bran, a small piece of inner, the germ, that contains the reproductive material, and a source of nutrition for the germ, the endosperm. The endosperm contains the starches and proteins necessary for the germ to grow into a new plant. These starches and proteins are what makes wheat the grain of choice for breads. The milling process typically removes the bran and the germ, leaving the endosperm as the flour as we know it. The bran is rich in minerals, which influences the ash content of the resulting flour. (see below)
Wheat Chemistry in Brief
The endosperm contains the proteins that make wheat flour able to contribute its qualities to bread. Two proteins, gliadin and glutenin, together constitute gluten. Gluten gives dough its structure and allows it to form the web-work of cells that trap the gasses released by the yeast, causing bread to rise. Gliadin gives bread dough extensibility, the property of being able to be worked and extended into the desired shape, whether it is round and squat or long and narrow. Glutenin gives dough the necessary resistance to shaping, which allows a dough to hold its shape. Working together, they allow us to form a loaf as we know it, allowing us to shape a loaf and have it hold that shape.
Bread bakers will encounter two competing measurement systems for flour, French and American. The American system measures with a 14% moisture content, while the French system assumes a 0% moisture. This causes large differences in the stated protein content of flours from the two countries. A French flour with a stated protein of 12% would be 10.5% under US measures, while an American flour of 12.5% would be 14.88% in France. (Calvel, page 4)
Ash content is another way that flour is measured. A standard amount of flour is burned and the resulting ashes are weighed. Ash content is specified as a percent of the original flour weight. Under the French measurement method mentioned above, a French flour with an ash content of 0.5% would be 0.425% in the US, while an American flour of 0.50% would be 0.605% in France. (Calvel, page 4) French flours are classified according to ash content. The famous Type 55 flour has a 0.55% ash content USING THE FRENCH METHOD. The ash content using the American method is 0.46%. The normally accepted ash content for bread flour in the US is around 0.52%, so the Type 55 flour is lower in ash than a normal US bread flour. (Calvel, page 4)
Why is ash content important? The ashes that are left over from the burning are a measure of the mineral content of the flour. The minerals contribute to the nutrition of the yeast during fermentation. Since the mineral content of the outer portions of the wheat berry is higher that the portions toward the center, it is also a measure of where the flour came from. A higher ash content flour will be darker and will handle differently from lower ash content flours, which will yield very inactive doughs. If you are comparing the ash content of two flours, be sure that the numbers you are using are based on the same system of measurement.
The Milling Process
As you read this section, you’ll learn a bit about the differences between US, French and Italian flours and the conventions surrounding their terminology and grading.
A wheat berry passes through several process steps in its journey from field to store shelf.
1. Harvesting. Nothing new here, just the process of cutting the wheat stalk and separating the berry from the stalk, also called thrashing.
2. Sweating. This is a six week resting period imposed after harvest and before milling. It allows a few chemical or metabolic changes to occur and allows the moisture level to stabilize at around 14%.
3. Cleaning. This gets rid of the various things that got collected along with the wheat berry — stones, sticks, weed seeds, etc.
4. Tempering. This is the addition of chlorinated water to prevent microbal growth. It also toughens the outer bran layers to make them easier to remove during milling.
5. Breaking. This is the initial step in the actual milling. It cracks, breaks, the bran layer and allows the germ and bran to be separated from the endosperm. Successive steps break the wheat berry components into finer and finer particles. As the process continues, more and more of the bran and germ are removed, which allows more flour to be recovered from the process.
6. Bolting. The sifting is called bolting.
7. Blending. Some of the ground up bran may be added back to the white flour, or different flour types may be blended together to give a composite flour with the desired characteristics.
8. Aging. After the flour is milled and blended, it is aged for a a period of time to give time for the chemicals in the flour to work on the proteins and starch.
9. Enriching. This is the process of adding small amounts of vitamins and minerals to flour to enhance their nutritional value.
10. Bleaching. Flour has to be aged after manufacture. Adding certain chemical agents reduces the time between manufacture and use. These agents can also increase whiteness and enhance some handling qualities. The chemicals in common use in the US are benzoyl peroxide, ascorbic acid and azodicarbonamide (ADA). Potassium bromate has been used, but is now viewed as possibly carcinogenic, so it is being phased out.
Extraction rate is the percentage of final flour obtained from a given weight of wheat berries. If we use all the products, the bran, germ and endosperm, and remove nothing from the flour stream (as it’s called), we term that a 100% extraction flour — we have extracted 100% of the possible flour from the wheat. Modern milling operations convert 72-76% of the wheat into white flour; this is termed a 72-76% extraction rate. If we add a bit more of the ground up bran, say to 78 or 80%, we have a “higher extraction” flour, one that has slight flecks of brown husk in it. A 100% flour is referred to as whole wheat flour. Whole wheat flour thus has all the germ and the bran in it, which means it also has the fats that are in the germ. This is the reason that whole wheat flour has a tendency to spoil much more quickly that a while flour. The intermediate extraction levels, from about 76 to something short of full whole wheat, are neither whole wheat or white; these are what people may refer to as “a bit of whole wheat in the dough.” If you can’t find an intermediate extraction flour, you can always mix a bit of whole wheat flour with white flour and get what amounts to any extraction level you want. Just consider the white to be 72% and the whole wheat to be 100% and go from there. (This isn’t exact, but it’s close enough for our purposes.)
Differing Names and Measurement Standards for Flour
So far, so good. Now things get a bit confusing.
In the US, we have cake flour, pastry flour, all purpose flour, bread flour, high-gluten flour and whole wheat flour. These definitions have their basis in the protein level of the flour, the fineness of the grind and the percentage of the bran that is in the final flour. We won’t concern ourselves with cake and pastry flour except to say that they are not generally useful for bread making. Some recipes, however, specify a small amount of cake or pastry flour in the belief that by mixing two types of flour they can approximate something in between. Raymond Calvel, in his book “Taste of Bread,” states that this is not possible, although he doesn’t say why. (“It has been put forth in some circles that French flours can be imitated by “cutting” the extra strength of North American bread fours with weaker cake or pastry flours. The logic of this is attractive, but it does not pan out.” Page 4.) I find this statement confusing, mainly because what the home baker would be attempting to do is what the miller does when he blends different types of flour to make a product. Maybe I’m just missing something, but I see nothing that indicates this process wouldn’t work.
All purpose flour is used to bake most types of non-bread goods, things like cookies, pies and cakes. It has a protein level of around 10-11%, although some all purpose flours seem to have a somewhat higher protein level, Hecker’s in particular.
Bread flour is a mixture of different streams of flour designed to give a protein level of 12-12.5% and an ash content of about 0.52%. Anything much lower than these levels will require some special handling to make bread, while higher levels will give other problems. In general, lower protein levels will be slower to ferment and will require less water, while very high protein flours will require more water and will yield chewy, tough breads. There are some flours on the market with very high protein levels, 14% or higher. These are specialty flours and shouldn’t be used for normal bread baking purposes.
Italian flours are named 00, 0, 1, 2 and integrale (whole wheat). 00 is the finest grind and whitest of the flours, with the amount of bran in the flour increasing as the number gets higher. I have seen small packages of 00 flour in my local Whole Foods. The price isn’t outrageous, so if you can find this flour, you could give it a try, especially for the DOC pizza as discussed in detail in Pamela Sheldon Johns’s wonderful book, “Pizza Napoletana!”
Whole Wheat Flour
If the miller leaves a goodly bit, or all, the bran or husk from the wheat berry in the flour, we term it whole wheat, since it is the whole wheat berry. These are also called Graham or whole meal flours. They are reputed to be “better for you,” although the possibles benefit a human could derive from a few shards of wheat husk might escape the average person.
In any case, there is no question but that breads made with a portion of whole wheat flour are distinctive. However, whole wheat flours don’t last as long on the shelf or in your pantry as white flours. The higher percentage of husk means that there are more oils in the flour, and the oils can “turn” or go rancid over time, which you usually discover when you go to make that special whole wheat bread for a special occasion.
Graham flour is a special type of whole wheat flour. In Graham flour, the wheat husks are separated out, ground very fine and then reincorporated into the flour.
Whole wheat flours in the US are usually much higher in protein content that white flours, some reaching almost 15% protein, with a correspondingly high ash content. In general, whole wheat doughs require a bit more water than white flour dough. They are also a bit trickier to develop, since the tiny shards actually cut the gluten strands, which can reduce the loft of a loaf. Don’t let these scare you off, though. You can add some whole wheat flour to just about any recipe without making any drastic adjustments. If you substitute up to 25% whole wheat flour for an equivalent amount of white flour, you’ll usually be all right. Anything above 25% can require a bit of adjustment to the recipe, usually increased yeast, or the addition of a bit of fat or oil.
Semolina and Durum, with thanks to Carol Field and her wonderful “The Italian Baker.”
Semolina is the product of a separate strain of wheat, Triticum durum. The terminology is a bit confused, but it appears that durum refers to the plant and the flour in general, and semolina refers to the flour in use. But I could be all wrong. In any event, the flour turns out a soft yellow color. It is usually ground into a flour that is coarser than normal white flour and is usually reserved for making pasta. However, it is possible to use this more granular flour for some excellent Italian breads. There is also a finely ground semolina flour that can be used for some specialty breads, although the protein content is too high to be generally useful unless the baker takes special care with water and mixing times. Coarse semolina is fairly easy to find, while the fine semolina flour is rare. The only source I have for semolina flour (the fine grind) is Bob’s Red Mill, which comes from Oregon and is very expensive. In general, I don’t like to buy products that have a very low turnover on the store shelves, especially when they have to be shipped a long way;the risk of spoilage is just too great.
I’ve used the grainier semolina to make the Pane Siciliano and it worked well, so it is possible.
What does all this mean for the bread baker? If you aren’t somewhat confused by all the above, then good on you! For the rest of us, here are some thoughts.
1. The French and Italians have been making wonderful breads for many centuries, using flour that North Americans would consider woefully deficient in terms of protein and ash content.
2. Most American and Canadian home bakers use bread flour with protein and ash content of 12-12.5% and 0.52%, respectively.
3. These translate into 14.8*% and 0.62% in French measurement, far above the vaunted Type 55, which is the standard flour used in making French breads. The French equivalent of 11.5% protein is 9.5% in US measurement. The Type 55 flour has an ash content of 0.55% in French measurement, which is 0.46% in US measurement, quite a difference from 0.52% for bread flour in the US.
The bottom line may be that American bakers are using bread flour to make breads that the French and Italians make with what is really all-purpose flour. Maybe, just maybe, we have been substituting protein power for technique in our bread baking. Maybe it’s time to take a look at plain ordinary all-purpose flour and master our techniques.