Soju, a clear distilled liquor made from rice, is the most popular alcoholic drink in Korea. Most bottles of soju will fall in the range of 20-40% alcohol (40-80 proof).
Soju has a clean, neutral taste that makes it a good accompaniment to Korean food or Korean snacks. People often say that the taste reminds them of vodka, but most commercial soju sold today has a sweeter and less aggressive flavor than vodka.
Soju was first distilled in Korea in the 1300s, and historians believe that the Mongols brought the Persian technique to Korea. It became one of the most popular spirits in Korea over the centuries until the Japanese occupation, when soju production was strangled and sake and beer became more popular. Following the liberation of Korea from Japan and the Korean War years in the 1950s, soju production was again in jeopardy by the rice shortage in the 1960s. The government made it illegal to use rice for soju, so instead distilleries began to use sweet potatoes, wheat, barley, and tapioca as replacements.
Most soju today is made not just with rice, but in combination with wheat, barley, tapioca, or sweet potato. Many members of the older generation prefer the stronger bottles of soju, but younger folks like the milder taste of the lower alcohol content varieties. Flavored soju is also now popular in flavors like apple, lemon, and peach, and it is also used in mixed drinks and alcoholic punches.