• Korean Journal of Microbiology
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• v.8 no.2
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• pp.53-64
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• 1970

In order to study ecology of microorganisms during Takju brewing, microflora changes were examined fromm the start to the sixth day of Takju fermentation in 24 hours intervals. Takju made from rice, flour and dried sweet potato in a liter volume open container at the laboratory and a sanple of Takju brewing factory were studied for their microflora and their changes during fermentationl together with a sample of Kokja. Results obtained were as follows ; 1. The followings were the identified microorganisms in Kokja. The molds ; Absidia spinosa, Aspergillus parasiticus. The yeasts ; Candida melinii, Candida Solani, Hansenula anomala. The bacteria ; Luctobacillus casei, Leuconostoc mesenteroides, Bacillus subtilis, Bacillus pumilus. 2. Torulopsis inconspicua, Lactobacillus casei, Leuconotoc mesenteroides, Bacillus subtilis, Bacillus pumilus were isolated from main mash of laboratory-made Takju samples. The yeast, Torupsis inconspicua which was not present in Kokja and, probably of a contaminant yeast, dominated the yeast flora of Takju mash of rice, flour and sweet potato of labotatory brewing. The laboratory brewing lost also always showed large population of lactic acid bacteria flora. 3. None of the wild yeasts which were present in Kokja appeared in Takju mashes. The Kokja appears to be of no use as the yeast source for Takju fermentation. Also the Kokja appears to be of not so effective amylolytic and proteolytic enzyme sources considering the microflora characteristics. Probably the major role of Kokja in Takju fermentation may be to contribute in taste formation. 4. Inoculation of Sacharomyces cerevisiae into the mash to the level of $10^7$ ml at the start of fermentation greatly changed the ecological aspects eliminating conditions of rather slow rising of natural contaminant yeast populaiton and fermentation which might give rise to prosperity of lactic acid and Bacillus bacteria that would be avoidable. 5. Examination of microflora of the large factory scale Takju fermentation showed the quite similar pattern of microflora and their changes to that of the cultured yeast-inoculated laboratory batch Takju fermentation. The cultured yeast dominated as the only predominant microflora, and the lactic acid bacteria flora were completely suppressed and aerobic bacteria, greatly. Probably this may be the regular microflora pattern of normal Takju fermentation. The role of lactic acid bacteria and aerobic bacteria in Takju fermentation may not be clear yet from this experiment alone.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5468-5475
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• 2015

This present work was aimed to analyse characteristics of fermentation and aging of Korean traditional cheongju prepared by adding of different brewing water. The three different mashes were used for fermentation and maturation. The cheongju(A) was prepared without adding of brewing water in two stage mashing. Cheongju(B) and cheongju(C) were made with adding of 1 liter and 2 liter brewing water in two stage mashing respectively whereas the cheongju(B) and cheongju(C) showed higher fermentation ability than that of cheongju(A) regarding to pH, ethanol, specific gravity and sugar concentration(brix). In terms of volatile compounds content after six months aging, cheongju(A and B) prepared by adding brewing water showed the higher content of ethyl acetate than that of cheong(C) and the concentrations were maintained during the aging period. In addition, the content of fusel oil(n-propanol, i-butanol, n-butanol, i-bmyl alcohol, n-bmyl alcohol)indicated similar pattern as ethyl acetate. The organic acid of cheongju B(4873.46 mg/l) and C(4963.12 mg/l) also indicated the higher content than that of cheongju A(4661.47 mg/l). In conclusion, cheongju B and C prepared by adding brewing water in two stage mashing showed better quality and taste than that of cheongju A.

• The Korean Journal of Food And Nutrition
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• v.12 no.3
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• pp.226-232
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• 1999

To evaluate the characteristics of modified nuruk made by inoculation and cultivation of Rhizopus jap-onicus T2, Aspergillus oryzae L2 and hansenula sp. BC26 three different Takju mashes were made with modified Nuruk commercial Nuruk and rice koji and the changes in microorganisms and major compon-ents of mashes were investigated uring brewing. The numbers of yeast kept higher in the mash of mod-ified Nuruk or rice koji. The numbers of lactic acid bacteria were high in mash of commercial Nuruk but those were not in mash of modified Nuruk or rice koji. all mashes showed stable pH in a day and the pH kept higher in mash of modified Nuruk than in that of commer-cial Nuruk or rice koji. Increase in the content of total acid was moderate in mash of modified Nuruk or rice koji but it was too much in that of commercial Nuruk. increase in the content of amino acid was much highr in mash of modified Nuruk or commercial Nuruk than in that of rice koji. Increase in the content of alcohol was more rapid in mash of modified nuruk or rice koji than in that of commercial Nur-uk. The content of reducing sugar kept highter in mash of commercial Nuruk or modified Nuruk than in that of rice koji. A small amount of modified Nuruk accomplished favorable fermentation showing nor-mal patterns in microbiological and physicochemical changes during brewing.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.877-886
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• 2019

Brewing with buckwheat as an ingredient has been proven to be successful in several previous studies. However, few studies have focused on the effects of buckwheat on the rutin content and antioxidant activity of beer. In order to develop a lager beer with high rutin content and desirable sensory characteristics, tartary buckwheat malt was used as a brewing adjunct. The results showed that the rutin-degrading enzyme was the key factor affecting the rutin content in the wort and beer. Compared to beer made using the common mashing method, the rutin content in the buckwheat beers produced using an improved mashing method was approximately 60 times higher. The total flavonoid contents in buckwheat beers also depended strongly on the mashing methods, ranging from 530.75 to 1,704.68 mg QE/l. The rutin-rich beers also showed better oxidative stability during forced-aging. Meanwhile, the buckwheat beers were found to be acceptable in terms of the main quality attributes, flavor, and taste.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.404-413
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• 2022

The process of manufacturing craft beer involves a wide variety of spontaneous microorganisms, acting in different stages of the brewing process, that contribute to the distinctive characteristics of each style. The objective of this work was to compare the structure of microbial communities associated with two different craft beer styles (Doppelbock and Märzen lagers), at a late maturation stage, and to identify discriminative, or style-specific taxa. Bacterial and fungal microbial communities were analyzed by Illumina sequencing of 16S rRNA gene of prokaryotes and the ITS 2 spacer of fungi (eukaryotes). Fungal communities in maturating beer were dominated by the yeast Dekkera, and by lactic acid (Lactobacillus and Pediococcus) and acetic acid (Acetobacter) bacteria. The Doppelbock barrels presented more rich and diverse fungal communities. The Märzen barrels were more variable in terms of structure and composition of fungal and bacterial communities, with occurrence of exclusive taxa of fungi (Aspergillus sp.) and bacteria (L. kimchicus). Minority bacterial taxa, differently represented in the microbiome of each barrel, may underlie the variability between barrels and ultimately, the distinctive traits of each style. The composition of the microbial communities indicates that in addition to differences related to upstream stages of the brewing process, the contact with the wood barrels may contribute to the definition of style-specific microbiological traits.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.895-900
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• 1997

Cyclodextrin (CD), which is one of food additives, was applied to Takju in oder to suppress the production of a stinking odor which its brewing and storage. CD was added to Takju in two different manners: one right after its brewing dilution stage, the other during its second mashing stage. After equal intervals of time, each sample was tested for fermentation process, storage capability, and sensory characteristics. The amount of CD ranged from 0.1 to 0.3% (w/w). The effect of CD on alcohol concentration, pH, total acidity and sugar content of Takju was shown to be more greatly influenced in the second sample rather than the first. The qualities of Takju were not affected by the addition of CD in the first sample. The sensory evaluation showed that the sample of the brewing dilution stage proved to be more attractive in the level of acceptability. However, when CD was over-added to Takju, the degree of acceptability declined due to the fact that the over-addition of CD suppresses its unique taste and flavor.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.516-519
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• 1995

Seven Korean milled rice samples (5 Japonica, 1 Indica, 1 Commercial) were used to compare the quality of brewing adjunct with that of U.S. IR36(Indica) sample was classified as having higher amylose and protein content and lower starch content than Japonica samples. IR36 sample did not differ from Japonica samples in wort color, wort viscosity, soluble protein, percent extract and sugar composition when it was used as brewing adjunct. Korean milled rice samples did not differ from U.S. sample in soluble protein, wort pH, wort viscosity, but lower in percent extract.

• Mycobiology
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• v.41 no.3
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• pp.139-144
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• 2013

Makgeolli is a traditional cloudy-white Korean rice wine with an alcohol content of 6~7%. The present study investigated the morphological characteristics, carbon-utilizing ability, fatty acid composition, alcohol resistance, glucose tolerance, and flocculence of Saccharomyces cerevisiae Y98-5 and Pichia anomala Y197-13, non-S. cerevisiae isolated from Nuruk, which is used in brewing Makgeolli. Similar morphological characteristics were observed for both isolated wild yeast strains; and the carbon source assimilation of Y197-13 differed from that of other P. anomala strains. Strain Y197-13 was negative for D-trehalose, mannitol, arbutin, I-erythritol, and succinic acid. The major cellular fatty acids of strain Y197-13 included C18:2n6c (33.94%), C18:1n9c (26.97%) and C16:0 (20.57%). Strain Y197-13 was Crabtree-negative, with 60% cell viability at 12% (v/v) ethanol. The flocculation level of strain Y197-13 was 8.38%, resulting in its classification as a non-flocculent yeast.

• Food Science and Preservation
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• v.20 no.4
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• pp.482-487
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• 2013

The quality characteristics of commercial fermented vinegars made with different ingredients were compared. The pH levels of the persimmon, fig, and brewing and rice vinegars were 3.60, 3.37, and 2.62, respectively. The total acid contents of the brewing, apple, and plum vinegars ranged from 6.33 to 6.57%. The free amino acid contents were detected in the following order: brewing vinegar (521.05 mg/100 g) > fig vinegar (358.89 mg/100 g) > persimmon vinegar (353.02 mg/100 g) > rice vinegar (122.31 mg/100 g) > plum vinegar (103.52 mg/100 g). The free amino acid contents of the commercial fermented vinegars were 56.85~358.89 mg/100 g, and their gamma-aminobutyric acid (GABA) contents, 0.21~27.22 mg/100 g. In particular, the GABA content of the fig vinegar was 1.3- to 100-fold higher than those of the other vinegars. The total polyphenol compound and total flavonoid contents were detected in the following order: persimmon vinegar > fig vinegar > brewing vinegar > rice vinegar. Hence, the results of this study can provide a new alternative for making functional vinegars containing organic acid and GABA.

• Food Science and Preservation
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• v.2 no.2
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• pp.269-276
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• 1995

Uncooked rice Tackju was prepared from the groud rice with different particle size such as 12, 20, 35 and 50 mesh, and its characteristics were analysed during the brewing. Reducing sugar and ethanol contents as well as yeast cell counts were the highest in main mash and Tackju prepared from 20 mesh fraction. Especially, reducing sugar content was about. 1.5-2.5 times as much as that obtained from 35 or 50 mesh fraction. The final concentration of ethanol in main mash prepared from 20 mesh fraction was 14.8%(v/v). It was about 1.5%(v/v) higher than the lowest one [13.35%(v/v)] which was prepared from 12 mesh fraction. No significant difference In total acidity was observed. Sensory evaluation revealed 20 or 35 mesh Tackju to be the best in overall preference, especially in sweet and refreshing tastes.