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Wood Aging of Beer. Part II: Influence of Wood Aging Parameters on Monophenol Concentrations
Abstracts / Cerevisia 38 (2013) 51–60
so that 40–60% of the grist consisted of malt with lower levels of one or more of these malt quality characteristics. With extract, blending resulted in additive improvements between malts of lower and higher levels. In contrast, improvements were synergistic for lautering performance when there was a substantial difference between the lautering performance of the two malts. The markers for synergism in lautering performance were the level of -glucanase and wort viscosity. Fermentability performance also typically showed synergism between low and high fermentability malts, with the exception of one malt sample whose blend combination showed an unexplained antagonism. The synergism in fermentability performance was achieved when there was a deficiency between the malts for Kolbach index, the diastatic power enzymes, or beta-amylase thermostability that compensated for the lack of these components in the lower-fermentability malts. The importance of these blending interactions was discussed in relation to malt quality specifications and achieving consistent and predictable brewing outcomes. http://dx.doi.org/10.1016/j.cervis.2013.09.007 Wood Aging of Beer. Part I: Influence on Beer Flavor and Monophenol Concentrations Journal of the American Society of Brewing Chemists, 2012, 70 (1): 55–61. F.L. Sterckx, D. Saison, F.R. Delvaux Wood aging is an old tradition that is still used to improve the sensory quality of wines, spirits, and some Belgian specialty beers. Today, it is gaining interest from brewers looking for new, innovative products. However, little is known about the actual influence of wood aging on beer flavor and composition. To elucidate the effect of wood aging on the flavor profile, a variety of oak chips was added to a commercially available beer, and the influence on the beer flavor and monophenol concentrations was determined. Sensory analysis showed spectacular effects of wood aging on the flavor profile of the studied beer, with clear increases in woody, vanillalike, spicy, and smoky flavor notes. Furthermore, nine monophenols (vanillin, acetovanillone, syringaldehyde, acetosyringone, guaiacol, 4-ethylguaiacol, eugenol, thymol, and salicylaldehyde) showed elevated concentrations following the addition of oak chips to beer. Both sensory effects and monophenol concentrations were associated with origin and toasting degree of the oak chips used.
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of acetovanillone, acetosyringone, and phenolic aldehyde concentrations. Finally, a summary of the results provides insight into the origin and formation mechanisms of the studied monophenols during wood aging. http://dx.doi.org/10.1016/j.cervis.2013.09.009 Comparison of the Rudin and NIBEM Methods for Measuring Foam Stability with a Manual Pour Method to Identify Beer Characteristics That Deliver Consumers Stable Beer Foam Journal of the American Society of Brewing Chemists, 2012, 70 (1): 70–78. D.E. Evans, M. Oberdieck, K.S. Redd, R. Newman A survey of the preferences of brewing professionals with respect to beer presentation and amount of beer foam was conducted at the ASBC Brewing Summit meeting in Providence, Rhode Island, in 2010. The survey showed that beer presentation in the Samuel Adams Boston Lager Perfect Pint glass was not only aesthetically pleasing but also promoted hop aroma and flavors in particular. Most of the survey participants preferred the presence of lacing on the glass during or after consumption and, on average, considered approx. 20 mm of foam immediately after dispensing into a glass as being optimal. The conventional NIBEM and Rudin methods for foam stability testing were compared with a simple method of manually pouring a beer into a Perfect Pint glass and visually scoring the stability after 5 min to determine the foam stability score (FSS). The NIBEM and Rudin foam stability measures were significantly but relatively poorly correlated. In part, this relatively poor correlation resulted from a wide range of beer viscosity in the sample set that inordinately influenced the Rudin results. In general, the NIBEM and Rudin foam stability measures were significantly correlated with bitterness, beer-foam-promoting proteins measured as Coomassie blue binding protein assay, beer color, alcohol, CO2 content, and pH, which was broadly consistent with previous studies. Although lipids are widely acknowledged as foam damaging, the measurement of total fatty acids (a lipid proxy) was not well correlated with either of the foam stability analysis methods. The FSS was significantly correlated to and largely predicted by CO2 content and beer-foam-promoting protein levels. These insights are discussed in relation to how brewers could design and consistently provide beers to customers that fulfill their foam quality requirements and expectations.
http://dx.doi.org/10.1016/j.cervis.2013.09.008 http://dx.doi.org/10.1016/j.cervis.2013.09.010 Wood Aging of Beer. Part II: Influence of Wood Aging Parameters on Monophenol Concentrations Journal of the American Society of Brewing Chemists, 2012, 70 (1): 62–69. F.L. Sterckx, D. Saison, F.R. Delvaux Wood aging of beer is an old tradition that is gaining interest from brewers looking for new, innovative products. In this article, a variety of process parameters that could influence the resulting flavor and monophenol concentrations in beer was investigated in model solution. The concentrations of nine of the studied monophenols increased quasilinearly with increasing amounts of oak chips. The extraction of these monophenols is enhanced by low pH (pH 3.5) and high ethanol content (8 and 10% [v/v]) of the extraction medium and relatively high storage temperature (20 ◦ C). On the other hand, the presence of oxygen and yeast caused decreases
Genetic and Malt Quality Diversity of East Asian Two-Rowed Barley Accessions in Relationship to North American Malting Barley Journal of the American Society of Brewing Chemists, 2012, 70 (1): 79–85. G. Tai YU, J.D. Franckowiak, R.D. Horsley, P.B. Schwarz Because of epidemics of Fusarium head blight (FHB) in the northern Great Plains of the United States and Canada in the past two decades, malting barley breeders have been forced to use nonadapted barley (Hordeum vulgare L.) accessions as sources of FHB resistance. Many of the resistant accessions are from East Asia, and limited information is available on their genetic diversity and malt quality. The objectives of this study were to determine the genetic diversity among 30 East Asian accessions and two North Ameri-
so that 40–60% of the grist consisted of malt with lower levels of one or more of these malt quality characteristics. With extract, blending resulted in additive improvements between malts of lower and higher levels. In contrast, improvements were synergistic for lautering performance when there was a substantial difference between the lautering performance of the two malts. The markers for synergism in lautering performance were the level of -glucanase and wort viscosity. Fermentability performance also typically showed synergism between low and high fermentability malts, with the exception of one malt sample whose blend combination showed an unexplained antagonism. The synergism in fermentability performance was achieved when there was a deficiency between the malts for Kolbach index, the diastatic power enzymes, or beta-amylase thermostability that compensated for the lack of these components in the lower-fermentability malts. The importance of these blending interactions was discussed in relation to malt quality specifications and achieving consistent and predictable brewing outcomes. http://dx.doi.org/10.1016/j.cervis.2013.09.007 Wood Aging of Beer. Part I: Influence on Beer Flavor and Monophenol Concentrations Journal of the American Society of Brewing Chemists, 2012, 70 (1): 55–61. F.L. Sterckx, D. Saison, F.R. Delvaux Wood aging is an old tradition that is still used to improve the sensory quality of wines, spirits, and some Belgian specialty beers. Today, it is gaining interest from brewers looking for new, innovative products. However, little is known about the actual influence of wood aging on beer flavor and composition. To elucidate the effect of wood aging on the flavor profile, a variety of oak chips was added to a commercially available beer, and the influence on the beer flavor and monophenol concentrations was determined. Sensory analysis showed spectacular effects of wood aging on the flavor profile of the studied beer, with clear increases in woody, vanillalike, spicy, and smoky flavor notes. Furthermore, nine monophenols (vanillin, acetovanillone, syringaldehyde, acetosyringone, guaiacol, 4-ethylguaiacol, eugenol, thymol, and salicylaldehyde) showed elevated concentrations following the addition of oak chips to beer. Both sensory effects and monophenol concentrations were associated with origin and toasting degree of the oak chips used.
53
of acetovanillone, acetosyringone, and phenolic aldehyde concentrations. Finally, a summary of the results provides insight into the origin and formation mechanisms of the studied monophenols during wood aging. http://dx.doi.org/10.1016/j.cervis.2013.09.009 Comparison of the Rudin and NIBEM Methods for Measuring Foam Stability with a Manual Pour Method to Identify Beer Characteristics That Deliver Consumers Stable Beer Foam Journal of the American Society of Brewing Chemists, 2012, 70 (1): 70–78. D.E. Evans, M. Oberdieck, K.S. Redd, R. Newman A survey of the preferences of brewing professionals with respect to beer presentation and amount of beer foam was conducted at the ASBC Brewing Summit meeting in Providence, Rhode Island, in 2010. The survey showed that beer presentation in the Samuel Adams Boston Lager Perfect Pint glass was not only aesthetically pleasing but also promoted hop aroma and flavors in particular. Most of the survey participants preferred the presence of lacing on the glass during or after consumption and, on average, considered approx. 20 mm of foam immediately after dispensing into a glass as being optimal. The conventional NIBEM and Rudin methods for foam stability testing were compared with a simple method of manually pouring a beer into a Perfect Pint glass and visually scoring the stability after 5 min to determine the foam stability score (FSS). The NIBEM and Rudin foam stability measures were significantly but relatively poorly correlated. In part, this relatively poor correlation resulted from a wide range of beer viscosity in the sample set that inordinately influenced the Rudin results. In general, the NIBEM and Rudin foam stability measures were significantly correlated with bitterness, beer-foam-promoting proteins measured as Coomassie blue binding protein assay, beer color, alcohol, CO2 content, and pH, which was broadly consistent with previous studies. Although lipids are widely acknowledged as foam damaging, the measurement of total fatty acids (a lipid proxy) was not well correlated with either of the foam stability analysis methods. The FSS was significantly correlated to and largely predicted by CO2 content and beer-foam-promoting protein levels. These insights are discussed in relation to how brewers could design and consistently provide beers to customers that fulfill their foam quality requirements and expectations.
http://dx.doi.org/10.1016/j.cervis.2013.09.008 http://dx.doi.org/10.1016/j.cervis.2013.09.010 Wood Aging of Beer. Part II: Influence of Wood Aging Parameters on Monophenol Concentrations Journal of the American Society of Brewing Chemists, 2012, 70 (1): 62–69. F.L. Sterckx, D. Saison, F.R. Delvaux Wood aging of beer is an old tradition that is gaining interest from brewers looking for new, innovative products. In this article, a variety of process parameters that could influence the resulting flavor and monophenol concentrations in beer was investigated in model solution. The concentrations of nine of the studied monophenols increased quasilinearly with increasing amounts of oak chips. The extraction of these monophenols is enhanced by low pH (pH 3.5) and high ethanol content (8 and 10% [v/v]) of the extraction medium and relatively high storage temperature (20 ◦ C). On the other hand, the presence of oxygen and yeast caused decreases
Genetic and Malt Quality Diversity of East Asian Two-Rowed Barley Accessions in Relationship to North American Malting Barley Journal of the American Society of Brewing Chemists, 2012, 70 (1): 79–85. G. Tai YU, J.D. Franckowiak, R.D. Horsley, P.B. Schwarz Because of epidemics of Fusarium head blight (FHB) in the northern Great Plains of the United States and Canada in the past two decades, malting barley breeders have been forced to use nonadapted barley (Hordeum vulgare L.) accessions as sources of FHB resistance. Many of the resistant accessions are from East Asia, and limited information is available on their genetic diversity and malt quality. The objectives of this study were to determine the genetic diversity among 30 East Asian accessions and two North Ameri-