Bakery flours are produced from a wide variety of wheat from various locations. These flours may also are milled from different grades and classes of wheat. There are 3 major classes of wheat kernels: 1- Hard wheat kernels that be milled to hard wheat flour, and this flour is used to make yeast raised products as bread and buns products. 2- Soft wheat kernels that be milled to soft wheat flour and usually used to make chemically leavening products as cookies and usually called pastry flour. And when this pastry flour is chlorinated (adding chlorine gas during milling) it is called cake flour. 3) durum kernel and usually is milled to semolina that produce pasta an noodle. Korban is considered a type of bread, because it is yeast raised product, therefore the ideal flour is hard wheat flour, however, all purpose flour which mainly a blend of hard wheat flour and soft wheat flour can be used to make Korban.
What makes the wheat flour unique in its ability to form an elastic dough? It is the gluten portion of the wheat proteins. By mixing the flour and water in to a dough, we develop the gluten into a continuous three dimensional phase or network. Desirable or good yeast raised dough must show sufficient resistant to extension to retain gas produced by yeast and also show enough extensibility so the gas cell can expand during proofing and baking without any rupture to the membrane between them. This balance between resistant to extension and extensibility is what gives us the cell structure and the volume of the final baked Korban.
Therefore, it is obvious that protein content and quality and the mixing of these proteins are critical factors. We will be talking about these factors and how they affect the final Korban shape, texture and volume in more details in the next edition.
Yeast is the essential ingredient in many bakery products. It is responsible for leavening the dough and imparting a delicious yeast fermentation flavor to the product. Yeasts are a group of microscopic organisms (single cell plants) that are found growing practically everywhere on earth.
It was first used in the production of beer and wine and then in the leavening of bread by the ancient Egyptians.
Types of Bakers Yeast
Several types of bakers’ yeast are prepared for use in various baking applications according to the preferences of individual bakers.
Compressed Yeast (Cake Form):
Compressed yeast is also called “Wet Yeast” or “Fresh Yeast.”
This yeast is perishable and should be stored under refrigeration (i.e. 38 F to 45 F) at all times prior to use.
Compressed Yeast (Crumbled Form):
This yeast is similar to the cake form of compressed yeast in every respect except that the compressed yeast is crumbled into small bits instead of being formed into blocks (cakes).
Regular Active Dry Yeast:
Active dry yeast is produced by drying specially prepared compressed yeast under carefully controlled conditions designed to preserve the activity of the yeast. For best results, this yeast should be re-hydrated with water at 100 +/_5 F before its use. Re-hydrating the yeast with water cooler than 80 F results in leaching of yeast solids from the cells, thereby reducing their activity. At temperatures above 110 F, the yeast will be damaged by the high temperature itself.
Instant Active Dry Yeast:
This is a relatively new type of bakers’ yeast that is prepared from special strains of yeast that have been fermented and dried under special conditions. These special processing conditions produce an instant active dry yeast product that may be added directly, without prior re-hydration, to the dry ingredients being used to prepare a dough.
The Role of Yeast in Fermentation
The basic action of yeast in bakery operations is the production of carbon dioxide (CO2) which causes the dough to rise. Yeast accomplishes this by breaking down the sugars through metabolic processes which are an essential part of the life processes of the yeast cells. This means that yeast feeds on (or ferment) sugar to produce carbon dioxide (CO2), alcohol, and some organic acids. Alcohol evaporates during baking, and carbon dioxide gas causes the product to rise and increase in volume and the organic acids contribute to the final flavor and the eating quality of the baked product.
What happened if the formula doesn’t have any sugar as in Korban formula ?. The bakers call the dough that doesn’t have any sugar and or less of the common ingredients as egg and milk a lean dough. In this case, nature plays major role, there are some enzymes naturally occur in the flour which break the starches to simpler sugars for the yeast to ferment.
These enzymes called Amylases (alpha and beta amylases). Beta amylase is found in wheat flour in abundant amounts but alpha amylase always need to be supplemented, and it has been a common practice for almost a century to add this enzyme in the form of malted barley flour.
Fermentation VS. Proofing
The fermentation process starts as the yeast mixed with the flour and water. The yeast uses the sugar in the formula or the starches in the flour to reproduce and multiply in the number of cells. Also, to some extent it produces CO2 and some organic acids. Actually the activity of the yeast at the fermentation period (30- 60 min) is 80% reproduction and 20% producing CO2.
The exact opposite is during the proofing time (15-30 min) which is 20% continue to multiply and 80% producing CO2. Therefore, the final shape and volume of the finished Korban occur during the proofing, which usually happened after cutting and forming the dough pieces.
Formula VS. Recipe
Formula, in most cases, means a list of ingredients to make a product on automated large scale equipment, where controlling, for example, the viscosity of the batter or the theology of the dough are necessary for a smooth run without downtime. Controlling, these parameters necessitate adding chemicals as dough conditioner, emulsifiers and gums. On the other side recipe means, the product will be made with the least equipments mostly by hands in a home kitchen sitting and need only the major ingredient, as flour, egg, milk…etc.
Active dry yeast VS. Instant dry yeast
In order to activate the active dry yeast, we need to dissolve the yeast in part of the formula water at 100 +/- 5 F before we add the mixture to the flour at the mixer. If the water above 110 F, it will kill the yeast cells, and if it is less than 80 F, the cells will leach out some solids (Cystein) which makes the dough very slacky (soft).
To avoid this step, we can use the instant dry yeast, and added to the flour directly without re-hydration.