Adzuki bean, also known as red small bean or red bean, is rich in starch and is also called "rice bean" by people. It is an indispensable minor grain in people's diet. As early as the Ming Dynasty, the "Compendium of Materia Medica" recorded the health benefits of adzuki beans: "promoting body fluids, promoting urination, reducing swelling, and stopping vomiting." It can "detoxify from alcohol, eliminate cold and heat pain and swelling, drain pus and disperse blood, and promote lactation." From ancient times to the present, adzuki beans have been mixed with other grains to make staple foods such as bean rice, bean porridge, and bean paste buns, which has become a time-tested scientific method of consumption.
There are two methods for making the bean paste for the buns: one is to not peel the beans. After the adzuki beans are boiled until soft, they are pounded into a paste with the skins on and then directly stir-fried. The other method is to pound the adzuki beans into a paste, pour it into a sieve, place a bowl of water underneath, and rinse it bit by bit. The bean paste sinks into the water while the skins remain in the sieve. After all the rinsing is done, the bean paste with water is placed in a pot and slowly stir-fried. When boiling adzuki beans, adding cold water after the water comes to a boil can speed up the process of them splitting open. When stir-frying the bean paste, do not make it too dry, as moisture will continue to evaporate as it cools. With the bean paste ready, add the fermented flour to an appropriate amount of alkaline solution, knead it evenly, roll it into a long strip, divide it into portions, and flatten each portion into a shape thick in the middle and thin at the edges, like a pot bottom. Hold the skin with the left hand, use a spoon with the right hand to place the filling in the center, seal the opening tightly, and shape it. After completing them all, steam them in a steamer, and you have bean paste buns with the health benefits of "reducing swelling and promoting urination."
In the view of Traditional Chinese Medicine, another reason for eating adzuki beans on snowy days is that the color red in food has the effect of increasing adrenaline secretion and enhancing blood circulation. Thus, folk medicinal recipes using adzuki beans have emerged:
Adzuki Bean and Mulberry Bark Decoction ("Supplement to Materia Medica"): 60g adzuki beans, 30g mulberry bark. Add water to make a decoction, remove the mulberry bark, and drink the broth while eating the beans. It has the effects of strengthening the spleen, promoting urination, and reducing swelling. It is mainly indicated for edema due to spleen deficiency, beriberi, and difficult urination.
Imperata Cylindrica Root and Adzuki Bean Soup ("Later Supplement to Prescriptions"): 250g imperata cylindrica root, 250g adzuki beans. Add water and cook until the water is gone, remove the imperata cylindrica root, and chew the beans in several portions. It has the effects of strengthening the spleen and promoting urination. It is mainly indicated for edema and difficult urination.
It is also worth mentioning that some people add alkali when cooking adzuki beans. Although this can make the beans soften faster, it destroys the nutritional components of the beans and reduces the body's absorption of iron.