It seems the teapot is too small as beans sprouted and fill up the entire teapot. The is some sourish smell as well, and it could due due to poor air ventilation within the teapot.
I need to take out some sprouted beans from the teapot into another container.
I decide to make a container with holes at the bottom which allow the roots to come out from the water and dip into the water underneath.
Sadly the storage area is too small.