Experimental purpose: to observe the phenomenon of yeast fermentation of flour dough under suitable temperature conditions

Experimental steps: 1. Take 250 grams of flour and dissolve it with an appropriate amount of warm water at about 30 degrees Celsius 1.5 grams of angel yeast,

2. Knead into a smooth dough and divide into two equal parts.

3. Take two clean food bags, put them in the dough, drain the air in one bag, and insert it into the mouth of the bag. Keep the other bag ventilated to spread the dough as thin as possible.

4. Place two food bags at the same time in an environment of 30 to 35 degrees for a small time.

Experimental results: (Write what you see) Probably The bag with clean air bulges, but the bag with ventilation has no obvious phenomenon. Or if you are exploring the fermentation method of yeast, it will be troublesome because yeast fermentation seems to be both anaerobic and aerobic, but aerobic will reduce its fermentation efficiency

Analyze experimental results: