If it becomes sour and sticky, it can't be used anymore. Because the fermentation time of flour is too long, it will breed toxins such as Escherichia coli and Aspergillus flavus and can no longer be eaten. Flour fermentation generally includes baking soda and yeast fermentation, that is, a large amount of carbon dioxide gas is produced in the dough, which is wrapped by gluten to form uniform and fine pores, so that the dough expands. Fermentation time is related to the sugar content, oil content and fermentation temperature of dough.

If the flour is sour and sticky after 6 hours of fermentation, it can't be used any more. If the flour is fermented for too long, it will breed toxins such as Escherichia coli and Aspergillus flavus and cannot be eaten. Dough will produce sour taste and become sticky and difficult to handle. However, if the fermentation is insufficient, the flour will be small in size, rough in texture and insufficient in flavor, so the fermentation needs to be properly controlled.