1. List of ingredients: The raw materials of monascus powder may have changed. Monascus rice is cultivated from steamed rice inoculated with monascus. High-quality monascus rice has bright color, light red color, fragrant smell and slightly sweet taste. If the mixed bacteria are polluted during the production of monascus rice or the rice is aged, the taste of monascus powder may be bitter.

2. Production steps: Too long fermentation time in the process of making steamed bread may also lead to bitterness. The normal fermentation time is generally about 40-60 minutes. If the fermentation time is too long, it may lead to bitter taste of steamed bread.

The above are only possible reasons, which need to be judged according to the actual situation. If this happens, it is suggested to try to change the source of monascus powder or shorten the fermentation time of steamed bread to see if it can improve the taste of steamed bread.