The practice of lotus seed soup sold on the street, what is that transparent paste?

It's lotus root starch. Stir lotus root starch with cold water. After the water for boiling lotus seeds is boiled, pour the prepared lotus root starch into the boiling water evenly and stir it quickly with a spoon, otherwise it will be piece by piece. It is best to stir at the same time. Longan, Fructus Crataegi and fresh fruit can also be added. For example, you can put some sugar in broken oranges, grapes, apples and pears ... Lotus seeds must be pressed in a pressure cooker, and longan must be peeled before making soup.