Guk

Guk (), also sometimes known as tang (), is a class of soup-like dishes in Korean cuisine. "Guk" and "tang" are commonly grouped together and regarded as the same type of dish, although "tang" can sometimes be less watery than "guk". It is one of the most basic components in a Korean meal, along with "bap" (밥, rice), and "banchan" (반찬, side dishes). In Korean table setting, "guk" is served on the right side of "bap" (rice), and left side of "sujeo" (수저, a spoon and chopsticks).
"Guk" is a native Korean word, while "tang" is a Sino-Korean word that originally meant "boiling water" or "soup". "Tang" has been used as an honorific term in place of "guk", when it denotes the same meaning as "guk" as in "yeonpo-tang" (연포탕, octopus soup), "daegu-tang" (대구탕, codfish soup), or "jogae-tang" (조개탕, clam soup). Generally, the names of lighter soups with vegetables are suffixed with "-guk", while heavier, thicker soups made with more solid ingredients used in "jesa" (ancestral rites) are often referred to as "tang". "Gamja-guk" (potato soup) and "gamja-tang" (pork back-bone stew) are different dishes; the potato soup can be called "gamjeo-tang."
Types.
"Guk" is largely categorized into four groups of soups, such as "malgeun jangguk" (맑은 장국), "gomguk" (곰국), "tojangguk" (토장국), and naengguk (냉국). "Malgeun jangguk" literally means "clear ("malgeun", 맑은) soup ("guk", 국) seasoned with a condiment ("jang", 장)," such as "doenjang" (soy bean paste) or "ganjang", and is served in a "bansang" (반상, regular meal table). The main ingredients for "malgeun jangguk" are meat, fish, vegetables, and seafoods. "Gomguk", also called "gomtang", refers to either a soup type made by boiling various beef parts such as rib, oxtail, brisket, head, and so forth for a long time, or made with ox bone by the same method. The broth of "gomguk" tends to have a milky color and to be rich and hearty taste. It can also be made with chicken or pork bone, to produce "samgyetang" or "gamjatang".
"Tojangguk" are based on "doenjang" broth and "ssaltteumul" (쌀뜨물, leftover water after washing rice for cooking). The taste is usually savory and deep. "Naengguk" are cold soups usually eaten in summer. These soups are usually clean and tangy, such as with "oi naengguk" (오이냉국, cold cucumber) and "miyeok naengguk" (미역냉국, cold wakame soup). "Kkaetguk" (깻국, sesame soup), made with chicken and sesame seeds, is thick and serves to replenish and supplement nutrients during hot weather.
"Tojangguk".
"Tojangguk" are eaten all year round. The term emerged in the 1930s in Korean cookbooks.
Naengguk.
"Naengguk" refers to all kinds of cold soups, mainly eaten in summer. They are also called "changuk" (literally "cold soup") in pure Korean while the term "naengguk" is a combination of a Hanja word and a pure Korean word with the same meaning. The first historical record on "naengguk" appears in a poem written by Yi Gyu-bo (1168–1241), a high officer of the Goryeo period (918–1392). "Naengguk" is referred to as "sungaeng" in the poem, which literally means "sunchaeguk", soup made with "sunchae" ("Brasenia schreberi"). Yi praised its clear and plain taste.
"Naengguk" is generally divided into two categories according to taste and ingredients. One group of "naengguk" is made by mixing chilled water and vinegar to give a sweet and sour taste; examples include "miyeok naengguk" made with "wakame", "oi naengguk" made with cucumber, "pa naengguk" made with spring onions, "nameul naengguk" made with garlic, and "gim naengguk" made with "gim" or "nori". The other group is made to supplement health and has rich tastes, such as chilled soup made with chicken, sesame, or soy bean.
"Gukbap".
"Gukbap" (국밥, ) are dishes developed from "guk". The term literally means "soup with rice." The dish is typically served in restaurants, and has become popular among the working class since the late Joseon Dynasty.