This section is from the book "A Treatise On Flour, Yeast, Fermentation And Baking Together With RecipesFor Bread And Cakes", by Julius Emil Wihlfahrt. Also available from Amazon: A treatise on flour, yeast, fermentation and baking, together with recipes for bread and cakes.
There are two distinct kinds of wheat flour, known as "Spring" and "Winter" wheat flour.
The "Spring" wheat flour is the strongest, as it contains the greatest per cent of gluten, and for this reason it will retain more moisture, thus producing a greater yield in both weight and volume of bread.
In Spring wheat, the same as in Winter wheat, there are two distinct classes, namely, "Hard" and "Soft." This difference is more apparent in the Winter wheat than in Spring wheat flour; but in both instances a hard climate and rich soil produce the best wheat, a flour with more strength, which means "Gluten."
But why is it that a given weight of flour varies in the quantity of bread it will make?
It is a question of absorption of water and retention of moisture.
Flour consists, so far as bakers need trouble about, of two constituents, namely, gluten and starch. Starch is the water absorber and gluten the moisture retainer. Therefore, capacity for water absorbing qualities in a flour does not mean strength. Again, the retention of moisture by the gluten does not represent water alone, as is so often stated. Generally speaking, the strength in flour considered by the baker is its toughness, elasticity and springiness, when made into dough. Some flours are good water absorbers and still lack strength, for, to be profitable, they must be good water retaining flours, and this is where the gluten comes in.
Of course, much depends upon the quality of gluten, as the quality differs exactly as the different grades of flour differ. In some flours, the gluten is so fine and delicate that, even if present in large quantities, is not capable of making a fair-sized loaf; again, in others the gluten is too hard, so that the flours must be over-fermented in order to get a good loaf.
These are the extremes on both sides.
The baker considers the tough-like flour, which makes a dough capable of stretching, and produces a sponge that is hard to break down when water is lifted on, as the ideal, with reference to strength, and the one with a high percentage of hard gluten. And so it is, for it has the sure sign of the strong flour; but it does not prove the most economical one, especially when the much-wanted flavor of bread is considered. When the flour is considered too strong, the fermentation must also be a very strong one, otherwise shapeless loaves, with great holes in them, will result. Therefore, a baker must consider what is suitable for him, as no general rule can be applied for all.
It becomes, therefore, necessary that the boss baker and the journeyman baker, alike, should have an exact knowledge of how to mix flours to get best results, and, at the same time, to supply the wants of the trade, considering flavor and size of loaves.
The "Spring" wheat flour, as before stated, is the strongest, and is rated, as to the quality, according to its strength.
The "Winter" wheat flour is divided into two classes, namely, "Red" Winter and the "Soft" white Winter flour. The red Winter is the harder, and has a reddish color when held to the light, as indicated by its name. The soft Winter wheat flour is the whitest, and its possible strength can often be judged by its color. In general, the white Winter wheat flour is mostly used for the manufacture of cakes and crackers, where gluten is of no value. But the baker, too, needs it, when he comes to consider the flavor and color of his bread.
Soft Winter wheat, which has a light, yellow tint, but whiter than Spring wheat flour - one that will keep the form when pressed in the hollow of the hand, and will fall apart easily when touched - may be considered a good flour to be used for blending. But a flour of the same color, when too dusty, or one of a blue tint, has no actual value or advantage for the manufacture of bread.
Soft white Winter flour contains less gluten than either the Spring or hard Winter. Its gluten is softer and more readily dissolved, acting as starter for dissolving the hard Winter gluten. The two combined facilitate the process of dissolving the Spring wheat gluten, through the action of the yeast. The Winter wheat flour, being more readily dissolved for fermentation, is the first nourishment for the yeast; hence, it naturally hastens fermentation.
Spring wheat patent flours retain the form given them by the pressure of the hand, when touched very lightly, they fall apart readily.
Clear Spring flour and hard Winter wheat flour have a more gritty feeling, and can also be distinguished by their color. The Spring patent has a yellow tint and is smooth to the touch. Clear Spring is of a more yellowish tint and is coarser, and has the same gritty feeling as has the hard Winter, only that the latter has a reddish tint. The white Winter is much softer to the touch than is the red Winter or the hard Winter wheat flour; and, again, the hard Winter is a degree softer to the touch than Spring wheat flour.
In this regard they compare as follows:
Clear Spring wheat flour is the hardest to the touch; then, in order, patent Spring, hard Winter, Winter patent, and last, soft white Winter wheat flour. Winter wheat flour, from which have been extracted the best ingredients in the manufacture of patent flour, will either make a hard form through pressure of the hand - one that will fall apart in lumps or will not form at all, but has the appearance of so much dust. Avoid such flours, even for the cheapest breads.
As before said, the quantity and quality of gluten contained in a flour constitutes its strength; but, again, gluten itself is divided into two distinct parts, namely, "Glutenin" and "Gliadin." A hard flour contains a larger per cent of glutenin, while a softer one usually contains a larger percentage of gliadin.
Gliadin is needed in larger proportions in the dough after the process of fermentation has taken place; but, unless rightly balanced with the glutenin, a flat and insipid loaf will result.
This is the most important point referring to the respective yield of flour and quality of bread. I will, therefore, treat this article separately and more thoroughly.
Low-priced flour does not mean economical flour, as the chief object must be to get the maximum quantity, with due respect for quality of bread.
Luckily, the miller today attends to the proper blending by mixing the various wheats to produce what may be termed an ideal flour. This obviates the necessity of a baker carrying too many different grades of flour on hand. There exists, no doubt, but what the miller makes his blend in the most conscientious way, and is in a better position to make the blends required. Nevertheless, it is not only necessary, but also becomes the duty for everyone who has the handling of flour, to ascertain its comparative value, by means of simple tests, easily accomplished, but whatever tests we may employ, the baking test is the final and only really satisfactory one.
Summing up, then, the gluten of a flour is its most valuable and important constituent, as it is the main substance distinguishing the characteristics of various flours. Again, the quality of the gluten should be its first consideration, as it really represents the stability of a flour. The water absorbing and retaining power of a flour is its stability. Flours that slack readily in the dough as fermentation progresses, and drop, before arriving at a certain standard proof, are by no means stable.
The stability of flour poor in maltose or sugar, can be increased by adding extra malt extract or sugar; again, flours lacking spring in oven during baking may be improved by the addition of extra lard. Consequently, by adding the proper amount of ingredients, a good commercial loaf is often produced from flour that would otherwise produce an inferior loaf of bread.
Another condition which controls the quality of bread is the temperature at which the flour is kept. Flour should not be exposed to an extremely low temperature, but should be kept, if possible, in a cool, dry storage, with an average temperature of 70° F. The storage room should be well ventilated, as flour absorbs and retains bad odors, so that it sometimes is noted in the bread.
Age itself has a tendency to whiten flour. If properly stored, it may be kept in good condition for a whole year, but by long storage flour is bound to lose some of its delicate flavor.