The Chinese character ju for alcohol was derived from a special pot that is used for fermentation. It has a pointed bottom and an amphora-like shape, which make it easy to separate the sediments that have settled at the bottom.
The Korean word sul, on the other hand, originated from the Chinese words su (meaning “water”) and bul (meaning “fire”). Over time, it came to be abbreviated as sul. The term “fire water” came from the boiling appearance of fermenting liquid (The Origin of Wine).

酉 => 酒

There is an old saying that goes, “Water was created by God, and sul was created by humans.”
The origin of alcohol is steeped in mythology. In Egyptian mythology, Isis’s husband Osiris taught the god of grains how to make beer. In Greek-Roman mythology, Dionysos-Bachus created the first alcohol. In the Old Testament, it was Noah, and in Chinese mythology, it was Princess Weechok.

What about Korea? The first alcohol story in Korea appeared in Jewang-Ungi, one of Korea's historical-archive books. It tells of a king who uses alcohol to seduce a woman and to make her pregnant. Her son’s name, in Chinese characters, was Sul.

Although there is little written evidence of the origin of alcohol in Korea, this does not prove that it was introduced thereto by China. It is possible that the process was introduced to Korea and China simultaneously by the first tribes that migrated to China and the Korean peninsula from Manchuria.
Korea has a long history of sul and of fermented foods.

Goguryeo was the northernmost of the three kingdoms on the Korean peninsula from the 3rd century to the 7th century (Three Kingdoms Era). The archaeological evidence indicates that the Goguryeo culture had a highly developed tradition of fermented foods and drinks. At that time, they made drinks using nuruk (fermentation mix) and malt. The methods used today were developed 1,700 years ago. The recorded methods of making sul date back from as early as AD 430. Gasahyop, the governor of the Sadong peninsula, recorded the technique during the era of the Wei dynasty of China. The Sadong region was a neighbor of the Korean peninsula and was familiar with its customs. This technique for making sul was transferred to China and Korea’'s Silla Kingdom. In China, it became the fine liquor gokaju while in Silla, it became known as the preferred drink of poets.

[Goguryeo Tumulus]

Baekje, the second of the three kingdoms during the Three Kingdoms Era, dominated the southeastern part of the peninsula. Sul was introduced to Japan from Baekje by Susubori (Korean for “brewer”), who came to be regarded as the Japanese god of drinks. According to the old Japanese archival text Ground Rice, Susubori offered sul to a Japanese king. It was the first time that the king tasted alcohol. It made him joyous, and he sang aloud. Although no records of Baekje’s sul-making techniques exist, the Japanese records of the period give us a good insight into it. They suggest that Baekje sul had the same high quality as that of Goguryeo.

aa Silla was the third of the three kingdoms during the Three Kingdoms Era, dominant in the southwest region and eventually unifying the peninsula in the 7th century.
Silla was a younger state and was at first less developed than Goguryeo and Baekje. The same can be said of their sul-making techniques. Silla, however, rapidly caught up with its older neighbors in all areas. The Silla text Jibung Yuseol gives evidence of Silla’s sul-making tradition. By the time Silla had unified the three kingdoms, the method of distillation had been developed, and drinking became popular among the upper classes during those times.

Developed the three basic kinds of Korean liquors: takju, yakju, and soju

This time in Korean history saw the development of the three basic kinds of Korean liquors: takju, yakju, and soju. The other drinks that were developed at this time were cheongju, jungyangju, takju, jaeju, and gamju, and the methods and skills became deeper and more highly graded. Further, the names of famous wines were formed in this era, such as hwanggeumju, samhaeju, nokpaju, baekhwaju, and ewhaju (high-grade makgoli). Besides making wine from grains, the methods of brewing wine made from fruits and medicinal herbs came and stayed.

Inflow of various foreign wines via active foreign transactions

The distillation practice was passed on from Arabia to the Mongols of the Yuan dynasty, then to Manchuria and into Korea, according to archived medical texts (Dongui-Bogam and Boncho-Gangmok). The common people could not obtain the same high-quality drinks during those times.

By this time, 300 different kinds of drinks had been developed, such as baekhaju, samhaeju, ewhaju, cheonggamju, buuiju, hyangonju, yaksanchun, hosanchun, and nosanchun. Soju had become so popular that Jeong Yakyong, a famous scholar and politician, suggested that the king take its distillers away from the common people. His logic was that the people were using too much of their rice to make soju and were not saving enough to eat. By banning soju production, the king would be able to preserve the nation’s food supply. In addition to takju, yakju, and soju, a fourth class of drinks was developed during the late Chosun period: gwahwajuryu, which was made very sweet or was mixed with soju to give it a longer shelf life.

Takju

Takju-Ihwaju ,Sajeolju, Hondonju, Hapju, Moju

Gamju

Gamju, cheong-gamju, yangju/cheongsoju, wasongju, juktongju, gahyangju, gwasilju

Soju (distilled)

Gongdokji soju, andong soju, chabssal soju, samhae soju-soju

Yakyong soju

Gwanso, gamhongro soju, iganggo, jukryeokgo

Hon yangju

Gwahaju, songsunju

Yakyongyakju

Jaju, gugiju, ogapiju, dosoju, milju, songjeolju

Yakju

Baekhaju, gugiju, samhaeju, buuiju, dugyeonju, gukhwaju, samhaeju, etc.