Just like leaving a piece of dough before steaming buns each time, it could serve as a yeast starter for the next dough fermentation—thus these things could be passed on one after another, sparing the trouble of having to add ingredients every time.
However, if it's done this way, the tofu factory could use Physalis as a starter, the tofu could use old brine, the sprouted beans could use the water from previously sprouted beans, and Tofu skin could use the soy milk left over after boiling. Salted duck eggs and century eggs could use the mixed slurry each time.
As for this sweet potato glass noodles, the layer of clear water on top during the starch purification process in the production could act as a starch-making starter the next time.
The only thing that probably can't utilize the principle of fermentation up to now is the formula powder for the mosquito repellent herbal medicine pack.