Active dry yeast/instant dry yeast is used as a biological leavening agent in food additives. Fermentation is the process in which yeast reacts with the sugar in the dough to produce carbon dioxide and alcohol.
The role of active dry yeast/instant dry yeast in the bread making process:
1. During the baking process, the alcohol evaporates due to heat, and the carbon dioxide expands due to heat, making the bread fluffy.
2. Improve the flavor of the product. The alcohol and organic acids produced during the fermentation of the dough can form a variety of aromatic substances during the baking process, thus increasing the aroma of the bread.
3. Increase the nutritional value of the product. Yeast contains a large amount of protein and vitamin B. These ingredients greatly increase the nutritional value of the bread and make it healthier to eat.
The differences and application methods of different yeasts.
1. Wet yeast
The moisture content of wet yeast is 65%-69%, so it must be kept in a low-temperature environment. It can be used as needed. When used, it can be stirred directly with the dough to produce fermentation in a short time. Wet yeast must be placed in the refrigerator. Storage, the general shelf life is about 15 days. If placed in a freezer at minus 25°C, the shelf life can be up to one year. However, if wet yeast is placed in a low temperature environment for a long time, the yeast activity will be weakened to a certain extent.
Generally speaking, wet yeast will produce better and faster dough, but it is not suitable for use in family life because storage is more troublesome.
2. Active dry yeast/instant dry yeast
Active dry yeast/instant dry yeast is made by pressing fresh yeast into short strips or fine granules and drying it at low temperature to produce dry yeast with a moisture content of about 8%. Compared with fresh yeast, dry yeast is more convenient to store and transport. Before use, dry yeast needs to be stirred and dissolved with warm water at about 30°C, and then mixed with the dough. The purpose is to activate it and stimulate its growth. Fermentation activity.
Active dry yeast/instant dry yeast has stronger fermentation endurance than wet yeast, but the fermentation speed is slower and not as fast as wet yeast.
3. Natural yeast
Natural yeast refers to a variety of fungi covering grains, fruits and in nature. Natural yeast has a better flavor than ordinary yeast because natural yeast can fully absorb water and mature for a long time. On the other hand, natural yeast is a variety of bacteria. When baking, each bacteria will emit a different aroma, making the bread The flavor is more diverse.
Before use, you need to mix it with warm water at about 30°C that is twice the amount of yeast, and place it in an environment of 25-28°C for about 30 hours to mature. Then use the required amount according to your own needs, and the rest needs to be refrigerated. .
Precautions for use:
1. Dry and wet yeast can be used instead, but it should be noted that the dosage of wet yeast is 3 times that of dry yeast. That is, when the dosage of dry yeast is 1 gram, 3 grams will be needed to replace it with wet yeast.
2. Whether it is dry yeast or natural yeast, if it is not used up at one time, the remaining yeast needs to be stored in the refrigerator.
3. Avoid stirring and mixing yeast with sugar, salt, and ice cubes, otherwise the yeast will die and become inactive and unable to ferment.
FAQ
What are the main visual, structural, and microscopic differences between active dry yeast and instant dry yeast?
The primary differences lie in how they are processed and their physical structures:
Active Dry Yeast: This yeast undergoes a gentler, slower drying process that leaves the yeast cells encapsulated in a protective outer layer of dead yeast cells. Visually, the pellets are larger, resembling tiny, round beads or sand grains. Because of the protective shell, the moisture content is around 7-8%, and it must be dissolved in liquid to break the shell before use.
Instant Dry Yeast: This yeast is dried rapidly using fluidized bed technology, which creates highly porous, elongated, needle-like, or fine-grained particles. Under a microscope, these pores allow liquid to penetrate instantly. It has a lower moisture content (around 5-6%) and a much higher percentage of live cells, allowing it to dissolve and activate immediately when mixed directly with dry ingredients.
How do the shelf life and ambient stability of these two types of dry yeast compare?
Because of their differing manufacturing processes and structures, their stability varies:
Active Dry Yeast: Thanks to its thick, protective outer layer of dead cells, active dry yeast is highly stable at room temperature. It can comfortably maintain its activity for up to 1 to 2 years when stored in a cool, dry place in its original sealed packaging.
Instant Dry Yeast: Due to its porous structure and lack of a protective shell, instant dry yeast is much more sensitive to oxygen and humidity. While it can also last up to 2 years when vacuum-sealed, its activity degrades rapidly once the package is opened. It must be sealed tightly and ideally stored in the refrigerator or freezer to preserve its leavening power.
