Plant starch.
According to information from Daoke Baba, the black liquid in the lotus root starch soup at the street stall is plant starch. The taste is smoother and more delicate.
Lotus root starch soup is spread on the ground. It is a casual delicacy made by brewing lotus root starch and condensing it into a solid state. It is sprinkled with a little sugar. The lotus root is fragrant and sweet.