Loosening the dough - role, properties, methods

[OPENING PROCESS]

OPENING PROCESS

This topic is partially based on material from the book "Professional Baking" by Paula Figoni

Loose foods are light and porous. They are larger and softer than loosened baked goods. These foods are also easier for the body to absorb.
Before describing the process of loosening, we note that there are three forms of it: solid, liquid and gaseous. When the temperature or pressure changes, the shape of the substance also changes. For example, when the temperature rises, solid ice turns into a liquid form - water, and water, in turn, turns into gaseous vapor. The reason for these changes is warmth. When heated, the molecules move faster and expand their impact. This expansion is the basis for loosening.
As the gases expand in the heat of the oven, they press against the wet, flexible pore walls. At the same time, the pores begin to shrink. As long as the materials of the structure stretch without tearing, the volume grows. When the baked goods are taken out of the oven, the gases return to their original volume. Products with a strong structure retain their shape. Foods with a weak structure (soufflés and half-baked cakes) shrink.
In this case, timing is very important. For a better volume, the expansion of the gases should take place while the product structure is still flexible. In the case of yeast products, the ideal conditions for expansion are during full fermentation, proofing and early baking. In cakes and instant breads, expansion occurs during baking, when the proteins coagulate and the starches gelatinize.
There are three main gaseous disintegrating substances used in baking: steam, air and carbon dioxide. Virtually all liquids and gases expand when heated, so they all loosen up to some degree. But only steam, air and carbon dioxide are naturally occurring and sufficient leavening agents in baked goods. Other liquids and gases that can be important in baked products, but are insignificant in quantity, include alcohol and ammonia.

[Steam]

Steam

Steam (or water vapor) is the gaseous form of water. It forms when water, milk, eggs, syrups, or any other moisture-containing ingredient is heated. Steam is a very effective leavening agent because, as it expands, it takes up more than 1600 times the volume of water. Imagine the power of this huge increase.
All baked foods are loosened with steam to one degree or another because they all contain water or other liquid. In fact, the effect of steam on loosening is much greater than one might imagine. For example, a biscuit cake depends on steam as well as on the air contained in the dough, as there are many eggs with a high water content in whipped biscuit dough.
Some baked goods, such as Shu cakes, are loosened almost completely with steam. These products contain a lot of liquid and are baked in a very hot oven.
Steam is also used in the initial stages of baking bread, when it is brought into the oven from the outside. This prevents the crust from forming too early and allows the bread, unrestrained by the hard crust, to rise to its full potential volume. Steam also affects the quality of the crust once it has formed. It helps gelatinize the starch in the crust, making it thinner, crisper and smoother.

[AIR]

AIR

It is easy to understand the importance of air in airy cakes.They contain beaten egg whites that add air to the dough. It's a little more difficult to understand the importance of air in other baked goods such as biscuits and biscuits. The dough for them almost does not change the volume after kneading, but still, without air, semi-finished dough products do not rise during baking.
Before describing the significance of air in loosening, it is important to understand how air enters the dough. Air is added to the dough by beating, sifting, rolling, kneading and even stirring. It is virtually impossible to mix ingredients without adding air. These physical processes also serve to divide large air bubbles into smaller ones. This contributes to the formation of a finer and more uniform crumb.

The important role of air in loosening

Like water, air is present in all baked goods. Unlike water, air is already a gas. When heated, it does not expand as much as water, and although the role of air is subtle, it is equally important. The air added to the dough is in the form of small air bubbles, or pores, that appear during the kneading process. These bubbles, or pores, present in the raw dough can be considered the "seeds" of the pores. During baking, steam and carbon dioxide pass into these pores and enlarge them. It doesn't matter how much water turns into steam or how much carbon dioxide is generated: new air pores are not formed during baking. Steam and carbon dioxide fill and enlarge the pores already present in the dough. Without these times, the gases would have nowhere to stay. Without them there would be no loosening. If we talk about the possible consequences, then without evenly spaced pores, ruptures of the dough structure by gases, as a rule, are directed into the product (in the opposite direction from the hardening crusts) and lead to the formation of one huge gap-bubble in the center of the product. Sometimes these breaks form just below the crust.
Remember that steam and carbon dioxide can form during baking and no new air pores are formed. The pores that already exist are simply enlarged.
This leads us to explain the important role of air in baking. The amount of air pores in the dough determines the crumb structure of the product. For example, unmixed cake dough contains too few air pores. The cake will turn out rough and with a small volume. The gases expand during baking and enter the pores, which are too few. The pores are large. The fewer air pores, the more they grow. Large air pores in baked goods mean coarse crumb.
Likewise, over-kneading the dough creates many air pores. Egg and gluten proteins in the pore walls are highly stretched. This makes the walls thin and weak. During baking, the pore walls stretch even more. The pores at the base of the product collapse under its weight. When is that occurs, a dense viscous layer is formed in the lower part of the product. And again we get a small volume.

[CARBON DIOXIDE]

CARBON DIOXIDE

Carbon dioxide is the only one of the three loosening gases that is not present in all baked products. Carbon dioxide is formed by yeast fermentation or chemical leavening agents. Yeast fermentation is a biological source of carbon dioxide. Chemical leavening agents (baking soda or baking powder are chemical sources
carbon dioxide.
Sometimes the role of carbon dioxide in the loosening process is exaggerated. Of course, carbon dioxide is very important in yeast and in some other products, but many cakes are loosened more with steam and air than with carbon dioxide. For example, a liquid shortening cake dough is kneaded until it is exceptionally light and filled with lots of tiny air pores. Cakes with a high water content create volume with steam. In such products, loosening powders play a secondary role.

[YEAST FERMENTATION]

YEAST FERMENTATION

Biological (or organic) formation of carbon dioxide mainly occurs during yeast fermentation. Fermentation is a process in which yeast cells (living microorganisms) break down sugar and release energy. Yeast uses this energy for survival and reproduction. Although yeast bread has been produced for thousands of years, it was only in the middle of the 19th century that Louis Pasteur proved that the fermentation process was caused by living microorganisms - yeast.
Yeast can be thought of as small enzyme machines that break down sugar into smaller, simpler molecules in several steps. However, there is no amylase in yeast and it cannot break down starch into sugars. This is why it is important to add amylase when baking bread, especially in soft doughs that mainly contain flour, water, salt and yeast.
The decomposition of sugar to carbon dioxide occurs in several stages. They were thought to be carried out by an enzyme called zymase.
We now know that each step is controlled by a separate enzyme. The term zymase is still used to refer to many of the enzymes in yeast that are involved in the breakdown of sugar. The whole process is as follows:
Many bakers will tell you that the most important end product of fermentation is carbon dioxide. However fermentation produces as much alcohol as it does carbon dioxide. The alcohol evaporates and expands during the initial stages of baking. This gives the bread a quick rise within the first few minutes of baking. Therefore, alcohol is also an important leavening gas in yeast products.
In addition to carbon dioxide and alcohol, a small number of flavor molecules are produced during fermentation, including many acids. The presence of these molecules is often overlooked, as there are too many of them by name and they are produced in very small quantities. Yet they are the source of a certain aroma of freshly baked bread. Slow fermentation often helps to better form the majority of the desired flavor molecules.

[FACTORS INFLUENCING YEAST FERMENTATION]

FACTORS INFLUENCING YEAST FERMENTATION

Several important factors affect the level of yeast fermentation.
Fast fermentation is desirable when time is limited.
Slower fermentation forms both flavor and gluten.
Bakers often adjust one or more of the following factors to optimize the degree of fermentation:

- Dough temperature. Yeast is inactive at 0 - 1 ° C. Their activity increases at 10 ° C. As the dough temperature rises higher, the degree of fermentation increases. But at temperatures around 50 ° C, fermentation slows down because yeast cells begin to die. Fermentation practically stops at 60 ° C, when most of the yeast cells die. Temperatures shown are approximate only. The actual temperature depends on the dough recipe and yeast deformation. The optimum fermentation temperature is approximately 25 - 28 ° C.

- The amount of salt. Salt slows down or suppresses yeast fermentation. The usual amount of salt in yeast dough is 1.8 to 2.5 baking percent. Bakers can change the amount of salt in the dough, making up for changes in the final batch. The dough contains yeast and a serving of other ingredients from the recipe. It is fermented before final kneading.
For fast fermentation, the dough is made with a little salt, and for a longer fermentation, more salt is added.

- The amount of sugar. A small amount of sugar (up to 5 baking percent) enhances yeast activity. Large amounts of sugar (above 10 baking percent) slow down fermentation. For this reason, the usual method for making a rich, sweet dough is to make a thick dough. It doesn't add much sugar and the yeast can ferment without hindrance.

- The type of sugar. Sucrose, glucose and fructose ferment quickly. Maltose ferments slowly, while lactose does not ferment at all.A mixture of fast and slow fermenting sugars is important in light yeast doughs, as it is low in sugar. This ensures that gassing continues in the final proofing.

- The pH level in the dough. The optimum pH for yeast fermentation is 4 to 6. Above or below fermentation slows down. When yeast is fermented, acids are formed and the pH is lowered.

- The presence of antimicrobial substances. Certain antimicrobial agents slow down or stop yeast fermentation. For example, calcium proprionate is added to a commercial dough. It must be added correctly so as not to stop the yeast fermentation. Many spices (including cinnamon) have strong antimicrobial properties and can slow down fermentation. Therefore, it is better not to knead cinnamon into the dough, but sprinkle the dough on top with cinnamon and sugar; then shape the dough into a jelly roll and roll it out before baking.

- The amount of yeast. Of course, the more yeast, the faster the fermentation. However, a high yeast content can impart an undesirable yeast flavor.

- Yeast type. Some yeast foods contain fast-fermenting yeast that works well in a non-steam dough. This also applies to instant yeast, which are described below.