Gamju or dansul is a traditional Korean alcoholic beverage, made from rice fermented with yeast-cake. Because its fermentation is incomplete, its alcohol content is relatively low. It is made from steamed rice, to which water and yeast-cake are added. It is then fermented for several hours in a rice-cooker at 60°C and served.
References
(Korean) "감주 [甘酒". Naver Encyclopedia. Retrieved on 2006-10-05.