Oi Naengguk: The Wisdom of Our Ancestors To Cool Down Heat

This year's summer solstice is on June 21, 2021. The summer solstice is the 10th of the 24 solar terms of the year, and the Sun’s declination is at its biggest during this period. Based on the Korean time zone, the summer solstice is when the Sun’s position in the sky reaches its highest at midday and the day with the longest period of daylight. It’s also the day with the most intense and longest amount of solar radiation. Because the temperature begins to rise significantly after the summer solstice, it’s considered to mark the beginning of summer. The 24 solar terms of the year, including the summer solstice, were first introduced to Korea during the Goryeo period, which shows our ancestors’ wisdom in preparing for the beginning of summer using astronomical knowledge.

You can also find hints of our ancestors’ wisdom in traditional Korean food. They used to make naengguk, which helps cool down the body heat and quench thirst, to survive the intense summer heat. One would usually think of a hot dish when you say ‘guk’ or soup, but naengguk literally means chilled soup. It’s seasoned with condiments like vinegar and sugar, without the use of any broth, and flaunts a refreshingly sweet and sour flavor. Sometimes, ice cubes are added to enjoy it even colder. Many different vegetables like cucumber, bean sprouts, seaweed, eggplant, and mu radish are used to make traditional Korean naengguk.

Cucumber is a popular ingredient for making naengguk, because it’s an easily accessible summer vegetable and has a refreshing flavor, crunchy texture, and high water content. It’s also written in <Donguibogam: Principles and Practice of Eastern Medicine> that from a perspective of yin and yang, cucumber is a vegetable with cold properties, so it helps with cooling down body heat. In fact, cucumber is rich in minerals, making it an excellent choice for quenching thirst. That’s why you see many people packing cucumbers instead of plain water when they’re doing outdoor activities such as hiking, camping, and fishing. Cucumbers are made up of 95% water and very filling, so it’s a great option for a healthy diet food to enjoy during the summer vacation season.

Why don’t we follow the example of our wise ancestors that endured the hot summertime with oi naengguk or chilled cucumber soup and make this summer cooler after this year’s summer solstice with oi naengguk as well? You can use the leftover cucumbers as a face mask and replenish moisture to your tired skin after being exposed to radiation.