• Journal of the East Asian Society of Dietary Life
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• v.18 no.1
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• pp.41-48
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• 2008

This study focused on the alcohol fermentability of traditional Nuruk, as well as yeast containing traditional Nuruk, in the production of Yakju. The fermentation performed with 30% Nuruk was effective with regard to alcohol yield. In addition, the fermentation containing 70% Nuruk showed the highest titratable acidity due to increased amounts of organic acids (succinic acid, oxalic acid, malic acid, acetic acid), which, however, negatively influenced the Yakju quality. Moreover, microbiological contamination always occurred in the fermentations using only Nuruk. In contrast, in the experiments with the yeast containing Nuruk, higher alcohol content and lower titrable acidity were obtained, independent of the Nuruk ratio used, positively effected the Yakju taste and flavor. Overall, the fermentation performed using the yeast containing 30% traditional Nuruk showed the best results for Yakju production.

• The Korean Journal of Food And Nutrition
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• v.6 no.3
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• pp.189-198
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• 1993

This study was carried out to investigate the effect of medium-cooked rice on brewing of yakju which was a traditional rice wine in Korea. The influences of cooking temperature of rice on hydrolysis of rice starch and rice protein were tested, and experimental brewings were done according to the traditional brewing method of Bangmunju in which some medium-cooked rice was used. The results obtained were as follows The hydrolysis of starch and protein in medium-cooked rice at 60~$65^{\circ}C$ was easier than that of full-cooked rice at 80~10$0^{\circ}C$. The amounts of saccharides, total amino acids and extracts In Yakju brewed with the combined use of medium-cooked rice and full-cooked rice were twice as much as those brewed with full-cooked rice only. The results of sensory test of Yakju brewed with the combined use of medium-cooked rice and full-cooked rice were better in taste, color and flavor than those brewed with full-cooked rice only. It was thought that our ancestor's traditional brewing method of Yakju in which medium cooked rice and full-cooked rice were used combinedly was excellent Judging from zymological point of views.

• Food Science of Animal Resources
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• v.31 no.6
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• pp.872-878
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• 2011

The quality properties of Gouda cheese supplemented with Korean traditional Yakju (Acanthopanax senticosus or Pueraria thunbergiana wines) were investigated. Yakju was added in the process of Gouda cheese preparation, and proximate composition, lactic acid bacterial population, pH, water-soluble nitrogen, sensory characteristics and proteolysis were determined. The electrophoretic patterns of cheese proteins, the target functional components and thiobarbituric acid values of the cheeses also were analyzed. The sensory characteristics including appearance of the cheeses were not affected by supplementing Yakju. Significantly higher amounts of crude ash, minerals and polyphenols were observed in the cheese supplemented with Yakju compared to the control cheese. The results suggest that the Gouda cheese prepared with Yankju has functional and additional nutrient values without changing cheese characteristics.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.3
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• pp.190-199
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• 2000

Information about the processing method of additional starter can be found in the 39 traditional kinds of classical literature. The traditional of Yakju, was analyzed and classified according to classical literature consist of 105 items relating to starters on those compounded alcoholics. 105 selected items were distributed among 5 groups of alcoholic beverages: processing methods of starter, additional starters for sweet and alcoholics, additional starters for Kwahaju, and those additional function for quality and quantity to the periodical conversion of the processing method through four centuries.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.61-66
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• 2005

Korean traditional rice wine Takju and Yakju were manufactured using 2-step-brewing method. To investigate microflora involved in fermentation step, number of microorganisms, pH, titratable acidity, and alcohol contents of Takju and Yakju were measured. In Takju and Yakju, although not significantly, $1.1{\times}10^{8}$ and $2.0{\times}10^{6}\;CFU/mL$ lactic acid bacteria at initial stage of second fermentation decreased to $8.3{\times}10^{6}\;and\;1.0{\times}10^{4}\;CFU/mL$ at the end of second fermentation, respectively. For Takju, micrococci and yeast occupied 80 and 20% at initial stage of second fermentation, whereas bacteria and yeast occupied 35 and 65% at the end of second fermentation, respectively. Yeast occupied 88% throughout the second fermentation of Yakju. The main yeast isolated from both Takju and Yakju was identified as Saccharomyces cerevisiae using API 20C AUX kit. The yeast strain Candida magnoliae was also detected during fermentation of Takju and Yakju.

• Journal of the Korean Society of Food Culture
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• v.26 no.1
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• pp.72-79
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• 2011

The purpose of this study was to investigate the fermentation characteristics of Yakju using fresh sprouts from common buckwheat, a Daisan cultivar, and a tartary buckwheat Daikwan 3-3 cultivar to develop a functional Yakju, which is a traditional Korean liquor. As fermentation time increased, alcohol concentration and total sugar content (expressed as Brix degrees) increased, whereas reducing sugar content decreased. In particular, alcohol formation capability was maximized from the fourth to the seventh days of the second mashing stage during the fermentation procedure, which corresponded to the abrupt rise in mashing body temperature. The pH increased slightly when the titratable acidity was kept from increasing as fermentation proceeded. Quercetin and rutin were not present in the control group but their presence in Yakju with added buckwheat sprouts continuously increased with an increase in the fermentation period. Quercetin and rutin contents were higher in the Yakju with added Daikwan3-3 buckwheat sprouts than Yakju with added Daisan buckwheat sprouts. In conclusion, adding buckwheat sprouts improved Yakju quality during fermentation. Particularly, Yakju with added Daikwan3-3 buckwheat sprouts had superior fermentation characteristics and quality.

• Food Science and Preservation
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• v.19 no.6
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• pp.925-932
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• 2012

This study was performed to improve quality of traditional Yakju and compares quality of Yakju according to different rice cultivars. The pHs of Ilmi Yakju and Hanarum Yakju showed 4.14 and 4.07, respectively and the other Yakju's pHs were ranged from 3.92 to 3.98. The content of total acid of Yakju using Indica rice imported from Thailand was the highest among the samples. The major components of free sugar was glucose and the highest content of total free sugars was found in Indica Yakju. The content of reducing sugars in Yakju using Indica rice was the higher than other samples. The ethanol content of Hanarum Yakju showed higher than those Yakju's and the lowest ethanol content found for the indica Yakju. The volatile compounds from the rice Yakju were identified by GC-MS. Twenty-one volatile compounds were found in rice Yakju. And the major volatile compounds were ethanol, acetic acid, 1-methyl-1-propanol, 2-methyl-butane, 3-methyl-1-butanol, iso-amylalcohol and 1-hexanol from Yakju. As the result of sensory test, higher scores for smell and color were found for the Yakju used Hanarum Yakju. The highest score sweat and acid were found for the Anda rice Yakju in sensory test. The result of sensory evaluation indicated that Hanarum Yakju and Anda Yakju were better than the other samples, and the value of bitterness was no significant in this test.

• Korean Journal of Food Science and Technology
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• v.48 no.3
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• pp.223-230
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• 2016

We investigated the fermentation characteristics of yakju made with nuruk extracts. Alcoholic fermentation was performed in an incubator set at $25^{\circ}C$ for 14 days. The study results are as follows: the alcohol content of yakju made with modified nuruk (18.67%) was higher than that made with other nuruk extracts (14.80-17.50%). The pH value of this modified nuruk (4.13) was higher than that of traditional nuruk (3.70-4.00). The yakju containing modified nuruk showed the highest acidity (3.64 mL/10 mL), amino acidity (4.72 mL/10 mL), soluble solid ($1.20^{\circ}Bx$), and color difference (39.78). The concentration of organic acids in traditional nuruks was 212.25-312.97 mg/100 mL, whereas that in modified nuruk was 295.92 mg/100 mL. Nitrogen compound concentrations in modified nuruk (2285.89 mg/L) were 2-14 times higher than that in traditional nuruk. Nitrogen compound concentration and amino acidity are the physiochemical characteristics with the highest impact on off-flavor and browning of yakju. In order to reduce these unfavorable characteristics, material with a lower protein content should be used.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.374-380
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• 2007

Chemical and sensory profiles of 5 Korean commercial rice wines (yakju) were developed using descriptive, physicochemical, and volatile analyses. Color, 6 aroma, and 5 taste attributes of these rice wines were evaluated by a panel of 13 judges. Sample wines were analyzed for titratable acidity, ethanol content, pH, Hunter colorimeter value, organic acids, and free sugars. Volatile analysis of the samples revealed the presence of 2 acids, 7 alcohols, 19 esters, and 5 miscellaneous compounds. Based on principal component analysis of the descriptive data, rice wines were primarily separated along the first principal component, which accounted for 57% of the total variance between the rice wines with high intensities of 'color' and 'sweet aroma' versus 'ginseng' aroma.

• Journal of the Korean Society of Food Culture
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• v.24 no.1
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• pp.1-9
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• 2009

The purpose of this research was to investigate consumers' perceptions of foods that are most compatible with traditional Korean liquors. The study participants were a total of 402 customers who visited traditional Korean bars. Thirty-eight percent of the participants drank alcohol once or twice a week, and overall, 79% drank with friends or co-workers. Forty-three percent spent 30,000-40,000 won on alcoholic drinks, and half of them frequently drank distilled Soju whereas 27% drank beer. Those who drank traditional Korean liquor chose to do so because they viewed it as good for their health and the beverage was tasty. Participants selected Yakju/Baekseju (47.5%), Bokbunjaju (21.1%), and Takju/Makgeoli (8.2%) as the most compatible Korean traditional liquors with Korean traditional foods. The most compatible foods with Yakju were identified as Haemulpajeon (11.8%), Dubukimchi (9.8%), and Bossam/Suyuk/Pyeonyuk (7.5%). Bokbunjaju was viewed as a good match with Jangeogui (8.1%), Hunjeori (6.5%), and Saengseonhoe (6.4%). The respondents perceived Deodeokgui (6.7%), Saengseonhoe (5.9%), and Dubukimchi (5.6%) as the most compatible foods with Yakju with mushrooms. Chengju was viewed as a good pairing with Eomuktang (9.2%), Altang/Maeuntang (7.2%), and Saengseonhoe (6.8%). The respondents thought Takju went well with Haemulpajeon (17.7%), Dubukimchi (14.2%), and Kimchijeon (11.7%). And finally, Altang/Maeuntang (11.8%), Samgyeopsalgui (8.7%), and Honghaptang/Jogaetang (8.1%) were mentioned as the most compatible foods with distilled Soju.