The purpose of this research was to appraise physicochemical properties by utilizing different Mit-sool, Juk, Seolgi-tteok, and Godubap, to produce traditional liquor. In all experimental plots, pH and amino acidity tended to increase with duration of fermentation. Titratable acidity displayed a very high number on the second day but then tended to decrease as fermentation progressed. Sugar contents were highest on the fourth day and tended to decrease with time. Alcohol content increased sharply at the initial stage of fermentation and increased gradually. On the 15th day, traditional liquor made with Godubap recorded the highest alcohol content. Common free sugar components were glucose and sorbitol. Common free organic acid components were lactic, succinic, citric, tartaric, malic, and acetic acids. Volatile flavor compounds were six alcohols, five esters, three aldehydes, and two ketones. Regarding overall acceptability in the sensory evaluation, traditional liquor using Seolgi-tteok as Mit-sool scored the highest. Overall, even though different types of Mit-sool had different physicochemical properties, there were no significant differences in volatile flavor compounds or sensory evaluation scores.

Fermentation characteristics and quality changes of the typical Korean traditional alcoholic beverages (Kwahaju, Sokokju, Baikhaju, Samhaeju and Hosanchun) were investigated during fermentation and after aging, respectively. They were prepared by their own brewing methods with respect to the same contents of rice and Nuruk (Korean-style bran koji). The consumed total sugar content of the alcoholic beverages (Sokokju, Baikhaju, Samhaeju and Hosanchun) which were brewed with the multiple input steps of seed mash and raw material (ABMIS) was higher than that of the alcoholic beverage (Kwahaju) which was brewed with the single input step (ABSIS). The pH values of all the beverages were similar and were ranged from 3.2 to 3.6. The acidity of ABMIS were lower than that of ABSIS, but alcohol concentration of ABMIS were higher. The fermentation period of the alcoholic beverages with triple input steps was the longest among them. The inner temperature and microbial growth in all the beverages increased at each of input steps of the raw materials. Fusel oil content of ABMIS was lower than that of ABSIS. Major components of the fusel oil were iso-amyl alcohol, iso-butanol, n-propanol, ethyl acetate and acetaldehyde, and its minor components were methanol and n-butanol. The results on quality changes of the alcoholic beverages after aging showed increase of alcohol in ABMIS, but decrease of sugar and acidity. Fusel oil contents of Kwahaju and Samhaeju decreased to be ranged from 3.1% to 13.9% after aging, but those of Sokokju, Baikhaju and Hosanchun increased to be ranged from 10.9% to 23.0%. Sensory evaluation of ABMIS showed better scores than that of ABSIS. It was suggested that the brewing method with multiple input steps of seed mash and raw material was one of the methods to increase fermentation efficiency for brewing the Korean traditional alcoholic beverages.

Physicochemical and sensory characteristics of Korean traditional alcoholic beverages, such as Kwahaju, Sokokju, Baikhaju, Samhaeju and Hosanchun were investigated during fermentation with the difference of input step and treatment of rice and Nuruk (Korean-style bran koji). pH values in all treatments were similar to be ranged 3.1~3.2, but acidity of the treatment brewed without seed mash was 1.5~2 times higher than that of the treatment brewed with seed mash. The concentration of alcohol in all treatments increased as the concentration of the Nuruk increased. The alcohol concentrations of Samhaeju and Hosanchun ranging from 6.5% to 7.7% were higher than those of Kwahaju, Sokokju and Baikhaju ranging from 7.9% to 10.6%. Residual reducing sugar contents of Kwahaju, Sokokju and Baikhaju ranging from 4.6 g/L to 9.7 g/L were lower than those of Samhaeju and Hosanchun ranging from 14.2 g/L to 15.5 g/L. The consumed total sugar contents of Kwahaju, Sokokju and Baikhaju ranging from 125.4 g/L to 159.2 g/L were higher than those of Samhaeju and Hosanchun ranging from 111.2 g/L to 123.8 g/L, and the treatments brewed with seed mash showed more sugar consumption than the treatments brewed without seed mash. Sensory quality in the treatments brewed with seed mash was better than those of without seed mash. Concentration of Nuruk and preparation of seed mash from it were critical factors compared to input step and treatment of rice in Korean traditional alcoholic beverage brewing.