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.
The question arises: What causes the different yield of flour? And the answer is: The quantity and quality of gluten in them.
But unless we go about in a careful manner and study these conditions, little benefit will be derived from the advantages gained in making a careful and well-proportioned blend.
Therefore, after we have the blend, we must next consider the fermentation agent, "The Yeast." Of course, the strongest and most uniform yeast is the best for the yield question, since, through proper manipulation, there need not be any loss noticeable during fermentation, while in stock yeast and other cheap yeasts, the loss extends from 4% to 15% of flour constituents during the process of raising dough. This means that in a barrel of flour from 1 to 30 pounds are consumed during the act of fermentation, and this constitutes the most nourishing qualities of the wheat and flour. This is one of the main factors why good compressed yeast is most universally used.
Of course, the yield of a flour is also governed by the kind of bread that is being made, and for that reason we must divide bread into two classes, namely, Oven Sole or Crusted Bread, and second, Tin or Pan Bread. The former of these are those that stand independently in the oven, and the dough for such loaves must be stiff enough and have sufficient strength of fermentation to stand upright without any support.
In addition to the various causes of variations in the relative yield already mentioned, there are others, such as sifting the flour directly before mixing of the dough and the proper application of machinery.
It is undeniable that the use of machinery compels a more systematic procedure. Likewise the loaf divider arrests considerable loss in scaling, whereas the dough-mixing machine itself, by giving the dough a good deal of agitation during mixing, develops the gluten, allowing the admission of more water than would be otherwise the case, at the same time producing a dough of the same consistency. The blade, or blades, sometimes called the agitator of a mixer, has a good deal to do with the length of time a dough must be mixed to derive best results. The best test is to look at the dough when finished and thereby judge the length of time best suitable for mixing a dough.
For example, a dough ordinarily mixed, say for comparison sake would require 6 hours for fermentation, then a dough properly mixed at higher speed would acquire its proper age in 4 1/2 to 5 hours. By shortening the fermentative period naturally more of the desirable ingredients are retained in the dough. This is especially true in reference to the sugar contained in the flour as well as added sugars to the mix. Developing the gluten means partially the softening of the protein contents of a dough, which otherwise is entirely left for the fermentation to accomplish.
Another point to be remembered in favor of employing quick methods is that they prevent a dough from slackening too much. In other words, a short fermentation increases the stability of the flour. This is an economical advantage.
To sum up, yields are increased by sifting flour immediately before using, and by shortening the period of fermentation. This is best accomplished by the use of a strong, uniform yeast, bakery machinery, and straight doughs.