How to determine whether yeast is ineffective

If yeast loses its activity, it is useless. However, many people cannot use their naked eyes to judge whether the yeast has expired. If you want to determine whether the yeast is expired, you can fill a bowl with warm water, then add a small spoonful of sugar, then add two spoonfuls of yeast, mix them together, and place them in a warm environment. If no foam appears, it means that the yeast has lost its activity.

How to identify whether yeast powder is invalid:

Put half a bowl of water, 35-40 degree warm water, into a bowl, add a small spoonful of sugar and mix evenly, then add 2 spoonfuls of yeast and mix evenly, place it in a warm environment, do not move it, wait for 5-10 minutes to see if there is any foam on the surface. If there is foam, it means it is active. Otherwise, it will be invalid.

1. After the yeast is dissolved in warm water, wait for 5-10 minutes. If the yeast is well active, a layer of foam will quickly float on the surface. If no foam appears or the foam is not obvious, it means that the activity of the yeast is not very good and it can no longer be used.

2. Add 1/2 teaspoon of sugar to warm water to act as nutrients for yeast, allowing the yeast to grow rapidly and facilitate observation.

3. If the dry yeast you purchased is in a large package, you can store it at room temperature before opening. After opening, please put it in a sealed bottle and refrigerate it in the refrigerator (5°C is best). The sooner you use it up, the better. For home use, it is recommended to buy yeast in small packages to avoid it losing its activity due to long-term unused yeast.

4. If the dough fails to rise, it is not necessarily due to the yeast. The temperature of the dough, the fat content, the amount of salt used, etc. will affect the fermentation speed and effect. But yeast failure is the most common problem.