Gray Bean is one of the special Lanzhou snacks and is boiled into a mushy state by hemp color peas. The method is to wash the hemp peas first and then boil them over a light fire. During boiling, add edible alkali and some red dates at the proper time. When the boiled dates have broken up the sweet juice flows into the soup, giving off a strong aroma. This dish is even more special if you add some sugar while eating.

Gray Bean Soup boasts soft beans and a thick soup, sweet dates and a fragrant smell, abundant nutrition and a low price. Drinking cold Gray Bean Soup in summer can drive away the summer heat, while drinking it hot in winter can nourish the liver and kidneys.

Du Weicheng in Lanzhou inherited the method of cooking Gray Bean from Ma You, a famous Gray Bean maker. Because of the special flavor of his soup, Du Weicheng was honored as "the king of Jincheng Gray Beans" by the Gansu Provincial Department of Commerce in 1989.