The effect of yeast generations on fermentation, maturation and volatile compounds of beer
The aim of the study was to determine the effect of yeast generations on fermentation and maturation processes, the content of volatile compounds of beer and viability and vitality of yeast biomass on an industrial scale. The experiments with fermentation and maturation were performed in fermentation tanks. The wort was aerated with sterile air. Yeast (S. pastorianus) bottom fermentation was used in fermentation. For pitching four generations (passages) of yeast were used as follows: 1st, 2nd, 3rd and 4th generation. The processes of fermentation and maturation were carried out in the same technological conditions (temperature and pressure). During fermentation and maturation, the changes in the content of the extract, yeast growth and vitality and selected volatile compounds like esters, alcohols and carbonyl compounds were investigated. With the increase in the number of yeast generations, especially from the 2nd generation used in the fermentation process, the content of acetaldehyde and esters increased. Despite the slight differences between generations, the changes are statistically significant. The content of diacetyl is stable for the 1st, 2nd and 3rd generation and higher for the 4th generation. Diversified yeast generations used in the process of fermentation did not affect significantly the final quality of beer.
wort; yeast generation; fermentation; volatile compounds; beer
Axcell B., O’Connor-Cox E. (1996): The concept of yeast vitality – an alternative approach. In: Proceedings 24th Convention of the Institute of Brewing, Asia Pacific Section. Institute of Brewing, Singapore, Indonesia: 64–71.
Jenkins C., Kennedy A., Hudgson J., Thurston P., Smart K. (2003): Impact of serial repitching on lager brewing yeast quality. Journal of the American Society of Brewing Chemists, 61: 1–9. https://doi.org/10.1094/ASBCJ-61-0001
Jin Y.L., Speers R.A. (2000): Effect of environmental conditions on the flocculation of Saccharomyces cerevisiae. Journal of the American Society of Brewing Chemists, 58: 108–116. https://doi.org/10.1094/ASBCJ-58-0108
Kordialik-Bogacka E., Diowksz A. (2013): Physiological state of reused brewing yeast. Czech Journal of Food Sciences, 31: 264–269. https://doi.org/10.17221/84/2012-CJFS
Kucharczyk K., Tuszyński T. (2018): The effect of temperature on fermentation and beer volatiles at industrial scale. Journal of the Institute of Brewing, 124: 230–235. https://doi.org/10.1002/jib.491
Lodolo E., Kocks J., Axcell B., Brooks M. (2008): The yeast Saccharomyces cerevisiae the main character in beer brewing. FEMS Yeast Research, 8: 1018–1036. https://doi.org/10.1111/j.1567-1364.2008.00433.x
Miller K., Box W., Boulton Ch., Smart K. (2012): Cell cycle synchrony of propagated and recycled lager yeast and its impact on lag phase in fermenter. Journal of the American Society of Brewing Chemists, 70: 1–9. https://doi.org/10.1094/ASBCJ-2011-1216-01
Müller A.G., Manger HJ., Lietz P. (2005): The yeast in the brewery. Management pure yeast cultures propagation. VLB Berlin, Germany: 135–137. (In German)
Powell Ch., Diacetis A. (2007): Long term serial repitching and the genetic and phenotypic stability of brewer’s yeast. Journal of the Institute of Brewing, 113: 67–74. https://doi.org/10.1002/j.2050-0416.2007.tb00258.x
Powell Ch., Quain D., Smart K. (2003): The impact of brewing yeast cell age on fermentation performance, attenuation and flocculation. FEMS Yeast Research, 3: 149–157. https://doi.org/10.1016/S1567-1356(03)00002-3
Sigler K., Matoulkova D., Dienstbier M., Gabriel P. (2009): Net effect of wort osmotic pressure on fermentation course, yeast vitality, beer flavor, and haze. Applied Microbiology and Biotechnology, 82: 1027–1035. https://doi.org/10.1007/s00253-008-1830-6
Stewart G. (2015): Seduced by yeast. Journal of the American Society of Brewing Chemists, 73: 1–21. https://doi.org/10.1094/ASBCJ-2015-0202-01
Stingheriu R. (2005): Preservation method of yeast and performance in beer fermentation. Journal of Agroalimentary Processes and Technologies, 2: 337–344.
Verbelen P., Tinne E., Dekoninck E., Van Mulders S., Delvaux F., Delvaux F. (2009): Stability of high cell density brewery fermentations during serial repitching. Biotechnology Letters, 31: 1729–1737. https://doi.org/10.1007/s10529-009-0067-5
Verstrepen K., Derdelinckx G., Verachtert H., Delvaux F. (2003): Yeast flocculation: what brewers should know. Applied Microbiology and Biotechnology, 61: 197–205. https://doi.org/10.1007/s00253-002-1200-8
Vidgren V., Londesborough J. (2011): 125th anniversary review: Yeast flocculation and sedimentation in brewing. Journal of the Institute of Brewing, 117: 475–487. https://doi.org/10.1002/j.2050-0416.2011.tb00495.x