Pat is one of the Korean food ingredients that foreigners are unfamiliar with.
 Not many people would be able to answer properly when asked, “What is pat?” 
Let’s take a look at some aspects of pat that we did not know much about. 

Source. Rural Development Administration

Distinctly different from soybeans

Pat(red bean) is a plant called sodoo(小豆) or jeokdoo(赤豆) in the pulse family, but it has a different shape and use from ordinary soybeans. Unlike the violet-colored flower of soybeans, the flower of the red bean is yellow. Although the flower shapes are similar, the red bean flower is bigger than that of the soybean flower. Furthermore, soybeans and red beans have different seed leaves. The seed leaf of soybean rises above the ground, whereas the red bean leaf stays underground. The number of kernels in a pod is also different. Soybeans have 1 to 3 kernels in a pod, while red beans have 6 to 10 kernels in a pod. 
Even though people are not aware of it, there are many different types of red beans. The main red bean varieties eaten in Korea are “chungjupat” with a red skin, “saegilpat” with a bright red skin, “arari” with a deep and dark red skin, “geomgooseul” with a black skin, “yeondoochae” with a light green skin, and “geopipat” with a thin and white skin.
 

Eaten mainly in Northeast Asia

Pat originated from Northeast Asia, and it has been mainly cultivated and consumed in Korea, China, and Japan for a long time. Its origin is not clear, but it seems to be old enough that there are records that the cultivation of red beans began 2,000 to 2,500 years ago in the Jemin Yosul(齊民要術), an agricultural book of the Northern Wei of China. In Korea, red beans were excavated from the Odong ruins in Hoeryong-gun. It is estimated that the cultivation of red beans started from the Bronze Age(the period of Moon pottery, 1,000 B.C. to 300 B.C.). The red beans used in Northeast Asia were brought to the Americas via Hawaii, and then spread to Australia, New Zealand, and Africa.
 

Used as additives in many dishes 

Rather than being consumed alone, red beans were used as a hunger crop and an important protein source during lean years, as well as additives in various dishes. It was made into red bean fillings and red bean paste, which were used in rice cake, traditional snack, bread, etc. In general, people think that red beans are sweet because sugar is added when they are used in cooking, but in reality, the sweetness of red beans is not that strong.
Patjuk(red bean porridge), which was eaten on Dongji(winter solstice), was a common red bean food in Korea. It was also widely used as a paste for rice cakes and bread. Red beans are a favorite food throughout the four seasons as it is used for making patbingsu(shaved ice with red bean topping) during summer.
 

Full of nutrients

Pat is made up of 68% carbohydrates and 20% protein. It is popular as a health food due to its anti-diabetic and antioxidant activities, as well as its effectiveness in preventing adult diseases.
Red beans are said to have an excellent diuretic effect in oriental medicine, they are also used to detoxify and eliminate inflammation. Saponin, which is commonly found in red beans, washes away skin waste, so it is said that during the Joseon Dynasty, courtesans ground red beans and mung beans, mixed them with water, or rubbed them on water-soaked faces, using them as natural soaps and scrubs. Moreover, red beans contain lysine and tryptophan, which are lacking in grains, so eating red beans mixed with grains is known to supplement nutrients.