Samgyetang has long been the most favored invigorating food of Korea, particularly in summer.  The food is cooked by putting glutinous rice, ginseng, jujube and garlic into the inside of chicken and boiling them fully.  There are 24 subdivisions of the seasons in lunar calendar, and among the subdivisions, 'early Bok,' 'middle Bok,' and 'late Bok' come during June ~ July. 

They are called 'three Boks,' covering the hottest days in Korea.  During those periods, people shed sweats heavily and lose appetite, thus easily falling into nutrition deficiency.  To overcome the sultry season, Korean ancestors had cooked and enjoyed samgyetang since the early days, and the tradition has been continued till now.

In the beginning the food was cooked by boiling young chicken, which was called 'Yeonggye baeksuk' (young chicken boiled in plain water).  Later, ginseng was added and the name changed to 'Gyesamtang' (chicken ginseng soup), which was again changed into the present name of 'Samgyetang.'  The book 'Seoul Encyclopedia' explains in detail the process of name change;
"Gyesamtang is a food stimulating appetite and supplying nutrition, cooked by fully boiling chicken added with ginseng.  Cut the belly of chicken, put ginseng inside it and thread the incised part.  Among special dishes taken in summer, this food was normally enjoyed by people better off than those who ate dog soup.  Its name had long been called 'Gyesamtang,' but later when ginseng became popularized and its value appreciated even by foreigners, the name has changed into 'Samgyetang' with ginseng as the first syllable."  
Like beef, chicken does not have fat in its sinew fiber.  It is a high-protein food smoothly digested and absorbed into human body.  Mixed in harmony with the medicinally-effective ginseng as well as glutinous rice, chestnut and jujubes, it produces balanced nutrition, and thus it is reckoned as an excellent stamina food. 

Chicken is a high-protein food with less fat and better digestion compared with beef or pork.  The protein created by chicken has excellent quality, and its fat acid contains linoleic acid which is effective in preventing adult diseases.  Chicken is also a desirable cuisine for the elderly and patients as it contains a lot of vitamin A, B1, B2 and niacin. 

The indigenous hens in Korea are comparatively small-sized, with the fully-grown one no bigger than large foreign chick.  They hatch twice a year, normally 15~20 chicks one time.  The indigenous hens are raised not being cooped up but left free in the garden, so they eat more natural feed and are more active than ordinary chicks.  As a result, their meats are solid, blackish red, tasty and sticky. 
Putting various herbs (which are recognized as Oriental medicine) into cooking has become popular recently in Korea.  In line with this trend, chickens are sometimes boiled with milk vetch and lacquer plant.  Special dish cooked by stuffing various herbs into chicken belly is offered at a higher price.  In raising poultry, organic feeds made by fermenting plants, or special feeds added with mugwort and seaweed, have come to be used instead of the conventional assorted feeds.

Samgyetang is a traditional dish of Korea which is useful in recovering physical strength in summer.  It is cooked by fully boiling chicken added with ginseng.  To be particular, glutinous rice, garlic and jujube are wrapped in an edible cloth and put into vacated belly of chicken, and, after pouring enough water, they are boiled in a pot or kettle for a long time.  When the contents are well done, they will be picked up and served on a dish. 
As a diversion of samgyetang, ginseng is wrapped in a cloth, put into soup and boiled sufficiently until ginseng components are soaked into the soup, and then the soup can be drunk up after seasoning with salt.  As another diversion, seasoned meat can be put into soup to be taken with the soup. 
Those who are losing appetite, suffering chronic fatigue or shedding much perspiration can obtain remarkable nutritious effect from samgyetang.  The exhausted physical strength in summer can be regained by taking the food.
Chicken which is a source of rich protein and essential amino acid, and ginseng which has been recognized as a wonder drug since the old days, are combined into samgyetang.  The combination is further reinforced by the nutritious effects of glutinous rice, chestnut and jujube.  Thus, the food could retain balanced nutrition.
'Dongeuibogam,' the famous old medical book of Korea, writes that "Of the ingredients of samgyetang, ginseng strengthens the function of heart and garlic gives the tonic effect.  Moreover, chestnut and jujube protect stomach and prevent anemia while pumpkin seeds exterminate parasites."