Bread retracts because of excessive fermentation, which leads to too much air and water in the internal tissue of bread. If it exceeds the tolerance limit of gluten, it will collapse immediately after brushing the egg liquid.

The way to avoid the collapse of the bread baked by the bread machine is to take it out and cool it immediately, so that it will not collapse.

There are many reasons leading to collapse, such as excessive fermentation of bread and enlarged pores, which will lead to collapse, insufficient kneading of bread, poor softness and fullness, or gluten fracture caused by excessive kneading, which will lead to collapse, too high oven temperature and short baking time, and it is also easy to collapse.