If baking powder is used to mix flour, it must be dissolved in warm water before mixing flour. Sometimes pancakes also use hot noodles, that is, boiling water.
Due to improper use of yeast or improper storage of yeast, live bacteria are unqualified.
Dry yeast, many times our impression of it stays on "a powder for fermentation", but we forget that it is also a microorganism and a fungus.
Since it is a fungus, there is life. It's just that the dry yeast we usually come into contact with is a compressed and dry product, and the yeast has been in a "dormant" state. When making fermented foods such as bread and steamed bread, the dry yeast will "wake up" and start to grow and reproduce, so that the dough will rise.
Similarly, since it is life, there will be death. If the dry yeast is not properly preserved or has passed the shelf life, a large number of yeast will die and no longer have the ability to ferment. Using this yeast to make bread will certainly not have a good effect-it will not only waste energy and time, but also affect your mood.
1. After the yeast is dissolved in warm water, wait for 5- 10 minutes. If the yeast is active, a layer of foam will soon float on the surface. If there is no floating foam or the foam is not obvious, it means that the activity of yeast is not very good and it cannot be used again.
2. Add 1/2 teaspoons of sugar to warm water as the nourishment for yeast, so that yeast can grow rapidly and be easy to observe.
3. If the purchased dry yeast is a big bag, it can be preserved at room temperature before being opened. Please put it in a sealed bottle and put it in the refrigerator after opening (5℃ is the best). The sooner you use it, the better. For home use, it is recommended to buy yeast in small packages to avoid losing its activity after a long time of use.
4. The reason why the dough doesn't rise is not necessarily yeast. Dough temperature, oil and salt content, etc. Will affect the fermentation speed and effect. But yeast failure is the most common problem. Therefore, detecting whether yeast is active can avoid making the simplest mistake.