• Food Science and Industry
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• v.52 no.4
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• pp.410-417
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• 2019

Soju is a traditional distilled spirit that may traced back to the 13th century, Koryo Dynasty in Korean Peninsula. It is the major distilled spirit consumed in Korea and it was considered Korea's most popular alcoholic beverage. Despite of the long history and popularity, its production manners have been limited developed in terms of distillation technology. In this article, a variety of distillation stills including batch pots and continuous columns are reviewed. Additionally, by introducing recent distillation technologies, Soju and distilled spirits related industry can apply the technologies on the product development for corresponding consumer's diverse needs.

• The Korean Journal of Food And Nutrition
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• v.15 no.4
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• pp.295-299
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• 2002

The esterification of alcohols with acetic acid, lactic acid and citric acid was carried out in batch during the second distillation. Effect of various parameters, e.g. pH of reactant base spirit, temperature of distillation, time of distillation were studied. The parameter of distillation temperature was modified by atmospheric distillation and pressure distillation. The pressure(1.9 atm.) distillation was used in order to react and distill at high temperature. Compared with the base spirit concentration, ethyl acetate, ethyl lactate and iso-amyl acetate in esterification distillate increased by 2,890%, 6,410% and 52%, respectively. Major factors of the esterification with organic acids in distilled spirit making were molecular weight of the organic acid and pH of reactant base spirit.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.369-376
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• 2017

Maturation of distilled spirit can generate diverse flavors and tastes. Rice Soju was matured in oak casks (MSO) and stainless steel containers (MSS) for one year at ambient temperature. Ipguk (Aspergillus luchuensis) and Saccharomyces cerevisiae Y88-4 were used, and reduced pressure ($110{\pm}20Torr$) distillation was applied to brew Soju. Acidity and conductivity were increased in both MSO and MSS. MSO reduced alcohol content (from 43 to 40%) and volume (from 18,000 to 12,730 mL), and significantly altered yellowness (from 0.2 to 30.2). Furthermore, MSO increased the isoamyl alcohol (from 276.7 to $339.2{\mu}g/mL$) and isobutyl alcohol (from 122.3 to $144.2{\mu}g/mL$) content. Gas chromatography-mass spectrometry was used to detect volatile compounds in Soju, which included 20 esters, 7 alcohols, 2 acids, and 5 miscellaneous compounds. Oak lactone was detected only in MSO and was considered as a specific flavor component associated with oak maturation. Thus, maturation materials contribute to the physicochemical property of distilled spirits.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.8
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• pp.3887-3896
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• 2013

The aim of this study was to select yeast strain for quality optimization of distilled spirit which is prepared using rice. Five yeasts strains were compared for their brewing characteristics and showed normal fermentation pattern, but songcheon yeast(Y1) and distillery yeast(Y5) revealed higher fermentation ability than other samples tested. The analyzed results of fermented mashing showed that the distillery yeasts(Y4, Y5) had significantly much higher alcohol content, and songcheon yeast(Y1), distillery yeasts(Y4, Y5) had significantly higher ester content than other samples tested respectively, while the distillery yeasts(Y3, Y4, Y5) had significantly higher organic acid content than other samples tested. The analyzed results of distilled spirits which were distilled using copper distillery apparatus showed that the songcheon yeast(Y1) and distillery yeast(Y5) had a higher yield compared to other samples tested. In addition, the results of the aroma compounds such as ester and higher alcohol of distilled spirits among the five yeasts tested were similar to the analyzed results of fermented mashing. Siha aktivhefe 6 brennereihefe(Y5) indicated the highest overall preference including sensory evaluation and was selected as best yeast strain for quality optimization of distilled spirit which is prepared using rice.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.383-389
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• 2017

This study aimed to select a yeast strain for optimizing the quality of distilled spirits. The brewing and distilling properties of 4 KFRI (Korea Food Research Institute) yeasts (Y88-4, Y98-4, Y172-6, Y192-4) and 2 industry yeasts (C1, C2) were compared. For investigating the possibility of using these strains on an industrial scale, diverse analytical methods were applied to assess parameters associated with distilled spirit quality such as alcohol content, pH, total acidity, and soluble solid content. After 11 days of fermentation, the alcohol strength obtained using six yeast strains reached 13.9-16.4% (v/v), while pH was 3.9-4.0, and total acid was 0.40-0.52%. To compare GC-MSD Volatile flavor components, all the distilled spirit samples were diluted to 20% (v/v) alcohol strength. Seven fusel alcohols, 26 esters, 2 acids, and 3 miscellaneous compounds were detected in the distilled spirits. Y88-4 had the most abundant volatile flavor component and scored the highest overall preference in sensory evaluation. After analyzing the various properties of yeasts, strain Y88-4 was finally selected as the best strain for producing distilled spirits.

• Applied Biological Chemistry
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• v.20 no.1
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• pp.66-80
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• 1977

This research was carried as a part of the basic study, in which the aptitude of theKorean oak varieties as barrels for aging apple fine spirits was investigated, and thefollowing results were obtained. 1. Following was the result of the chemical analysis of the fruits which are now mass-produced and can be used as a substitute for raw materials for wine production. Apple (Malus pumila Miller var. domestica Schneider) : Total sugar. total acid, volatile acid and pectin of Jonathan (Hong-og) were 13.95%, 0.46%, 0.012%, 0.20% respectively. Total sugar, total acid, volatile acid and pectin of Ralls (Koog-kwang) were 13.35%, 0.43%, 0.011%, 0.45% respectively. 2. Because of low yield of apple juice due to cellulose, pectin, hemicellulose which are present besides sugars, acids in apples, the apple juice were treated with xylanase of Aspergillus niger SUAFM-430, cellulase and pectinase of Aspergillus niger SUAFM-6. This treatment increased the yield of apple juice. And the apple juice was sterilized by adding potassium metabisulfite $(K_2S_20_5)$ and Saccharomyces cerevisae var. ellipsoideus Rasse Johannisberg II (SUAFM-1018) as a cultivation yeast, which has a strong fermentation power was used to ferment. The yield of apple wine based on raw material was 86-87%. The amount of ethanol, extract and methanol obtained from Jonathan and Ralls were 13.5%, 5.4%, 0.04-0.05% respectively. 3. Wines were distilled for two times by the pot still method to make fine spirits. The yield of fine spirits from apple wine mash was 86.6%, and the pH of fine spirits from Jonathan and Ralls were 4.1, 4.2 respectively. 4. The oak chips made of inner part or outer part of 24 Korean oak varieties were used to select the barrel for aging fine spirits. Two oak chips (one oak chip: $1{\times}1{\times}5cm$) of the inner part or of the outer part of each oak variety were dipped into 300 ml of fine spirits, which was bottled in 640ml beer bottle, and followed aging. The colors, flavors and tastes of the fine spirits were checked during 6 months. A. As a criterion for the first screening of oak barrels for aging fine spirits, the rate five of color extraction was determined. The oak chips showed good results in their order as follows and the best 5 varieties were selected. Gal-cham: Quercus aliena Blume (Inner part), Gul-cham: Quercus variabilis Blume (Outer part), Gal-chain: Quercus aliena Blume (Outer part), Jol-cham: Quercus serrata Thumb (Inner and Outer part). Sin-gal-cham: Quercus mongolica Fisher (Outer and Inner part) Sang-su-ri: Quercus acutissima Carruthers (Outer and Inner part) B. To find out the influence of aging temperature on aging, apple fine spirits were aged by dipping each oak chip at room temperature $(24-25^{\circ}C)$) and $45^{\circ}C$. Aging at $45^{\circ}C$ gave the best result followed aging at $30^{\circ}C$ and then at room temperature. C. Apple fine spirits was aged for six months by dipping oak chips in Erlenmeyer flasks and was irradiated with U.V light. The U.V irradiation enhanced the aging effect by nearly two times, compared with the aging without U.V irradiation. D. In aging apple fine spirits by dipping two oak chips, it was observed that the extent of the extraction of most components of oak chips were strongly dependent upon the pH of fine spirits. E. Oak chips of five selected oak varieties and a Limousin white oak from France as a control were used. Each apple fine spitits was dipped by two oak chips, and was aged at room temperature $(24-25^{\circ}C)$, $30^{\circ}C$, $45^{\circ}C$, and with the U.V irradiation at room temperature shaking every week. After six months of aging, the panel test of these aged fine spirits (Young Brandy) showed the following result. Young brandy of apples aged at $45^{\circ}C$ by dipping oak chips of Gal-chain was almost as the fine spirits which were aged at room temperature by dipping Limousin white oak chips from France. Young brandy of with U.V. irradiation at room temperature which were aged by dipping oak chips of Gal-chain was a little worse than that from the fine spirits aged at room temperature by dipping Limousin white oak chips from France. And so, Korean oak varieties are thought to be able to be used for aging every apple fine spirit which was here investigated.

• The korean journal of orthodontics
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• v.30 no.4 s.81
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• pp.475-481
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• 2000

The purpose of this study was to evaluate the effect of oral environment on the strength of resin bracket wings by comparing fracture mode according to water immersion and thermocycling. Seventy-five resin brackets(Spirit MB, Ormco, California) were divided into three groups and treated for six months as follows; (1) untreated, (2) water immersion in distilled water at $37^{\circ}C$, (3) water immersion in distilled water at $37^{\circ}C$ with total 2,100 times of thermocycling taken 350 times each month. Fracture mode of the wing was tested on universal testing machine. In addition to resin brackets, 25 metal brackets were used as controls. Through the statistical analyses, following results were obtained. 1. Resin bracket wings showed significantly lower fracture strength than metal brackets(p<0.001). 2. Water immersion and water immersion with thermocycling groups showed significantly lower fracture strength than open air condition group(p<0.001). 3. Water immersion with thermocycling group showed significantly lower fracture strength than water immersion group(p<0.001). The above results suggest that the mechanical property of resin bracket wing nay be influenced by oral environment and further research is needed to improve the strength of the wing in the resin bracket.

• Analytical Science and Technology
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• v.21 no.1
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• pp.53-57
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• 2008

In order to survey the contents of ethyl carbamate in alcoholic beverages, GC/MS-SIM method was used after extraction with dichloromethane in solid phase extract cartridge contained alcoholic beverages. In the applied GC/MS-SIM method, the values of recoveries and relative standard deviation were ranged from 85.2 % to 87.9 % and from 0.7 % to 1.9 %, the limit of detection and quantification were $2{\mu}g/kg$ and $10{\mu}g/kg$. Depending on alcoholic beverage kinds, the levels were variable and the average level was $194{\mu}g/kg$ for liquor, $105{\mu}g/kg$ for fruit wine, $62{\mu}g/kg$ distilled spirit, $28{\mu}g/kg$ for sake, $15{\mu}g/kg$ for yakju, $12{\mu}g/kg$ for other alcohol beverages, ND for soju, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.2012-2018
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• 2013

The objective of this research was to investigate the quality characteristics of the spirits by different distillation and filtrations. The contents of alcohol, total acids, and amino acids in rice mash were 15%, 0.25 g/100 mL, and 0.15 g/100 mL, respectively. The soluble content was $10^{\circ}Brix$, and pH was 4.6 in the rice mash. Lactic acid was the most prominent organic acid found in rice mash. The rice spirit distilled by a multi stage distiller showed the highest amounts of aroma compounds, such as fusel oil and esters. However, the filtration did not affect the amounts of total aroma compounds. It is suggested that a multi stage distiller may influence taste and flavor positively by enhancing the aroma and removing the impurities in rice spirits.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1510-1516
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• 2015

The objective of this study was to investigate the quality and sensory characteristics of sweet persimmon mashes and spirits fermented by three different yeasts [Saccharomyces species, labeled as LB (Lalvin BM $4{\times}4$), LD (Lalvin DV10), and UC (Uvaferm CM)]. In the production of sweet persimmon wines, UC had the highest alcohol content of 10.20% (v/v) after 9 days of fermentation (P<0.05). The range of pH after fermentation was 3.63~3.75. The total aerobic bacteria and yeast contents increased until day 3 and then continuously decreased to approximately 8.60 log CFU/mL and 8.20 log CFU/mL, respectively. Reducing sugar contents were 3.37% in UC, 3.91% in LD, and 4.05% in LB after fermentation. Total sugar contents were 4.89% in UC, 6.24% in LD, and 5.47% in LB after fermentation. Two-stage single-pot distillation was conducted to produce sweet persimmon spirits. While conducting second distillation, spirits were collected every 100 mL fraction. The alcohol contents gradually decreased as more fractions were collected. The amounts of acetaldehyde were 226 mg/L for LD, 225 mg/L for LB, and 310 mg/L for UC in the first fraction. LD produced the highest volume (677.8 mL) of alcohol in its body part in comparison with LB (408.0 mL) and UC (445.4 mL). In the descriptive analysis, UC had stronger intensities of sweet aroma, sour aroma and taste, and persimmon flavor (P<0.05). Persimmon characteristics seemed to be well characterized by UC. In conclusion, LD was the most efficient in terms of production cost, whereas UC would be used to produce a more flavorful sweet persimmon spirit.