Mashes to Mashes, Crust to Crust. Presenting a novel microstructural marker for malting in the archaeological record

The detection of direct archaeological remains of alcoholic beverages and their production is still a challenge to archaeological science, as most of the markers known up to now are either not durable or diagnostic enough to be used as secure proof. The current study addresses this question by experimental work reproducing the malting processes and subsequent charring of the resulting products under laboratory conditions in order to simulate their preservation (by charring) in archaeological contexts and to explore the preservation of microstructural alterations of the cereal grains. The experimentally germinated and charred grains showed clearly degraded (thinned) aleurone cell walls. The histological alterations of the cereal grains were observed and quantified using reflected light and scanning electron microscopy and supported using morphometric and statistical analyses. In order to verify the experimental observations of histological alterations, amorphous charred objects (ACO) containing cereal remains originating from five archaeological sites dating to the 4th millennium BCE were considered: two sites were archaeologically recognisable brewing installations from Predynastic Egypt, while the three broadly contemporary central European lakeshore settlements lack specific contexts for their cereal-based food remains. The aleurone cell wall thinning known from food technological research and observed in our own experimental material was indeed also recorded in the archaeological finds. The Egyptian materials derive from beer production with certainty, supported by ample contextual and artefactual data. The Neolithic lakeshore settlement finds currently represent the oldest traces of malting in central Europe, while a bowl-shaped bread-like object from Hornstaad– Ho¨ rnle possibly even points towards early beer production in central Europe. One major further implication of our study is that the cell wall breakdown in the grain’s aleurone layer can be used as a general marker for malting processes with relevance to a wide range of charred archaeological finds of cereal products

Optimización del malteado de avena (Avena sativa L.) como materia prima de bebidas fermentadas

The influence of the three malting parameters (germination time, germination temperature, and degree of steeping)on the quality of two oat (Avena sativa L.) cultivars was investigated applying response surface methodology. Eachpredictor variable was tested at three levels, germination of 6 to 8 days; germination temperatures of 12, 15, or 18°C; and degrees of steeping of 43%, 45% or 47%. All analyses were based on methods described in EBC or MEBAK. The oats used were obtained in 2007 from Nordsaat Saatzucht GmbH, Böhnshausen, Germany. A series of malt quality attributes were evaluated including extract, apparent attenuation limit, Kolbach index, α-aminonitrogen, color, β-glucan, and viscosity. Oat malt was optimized based on barley malt specifications, which are considered appropriate in the beverage production industry for optimal processing. For cv. Ivory, the optimal malting program was achieved after 8 days of germination with moisture content of 46%, and at 17°C. Similarly, cv. Typhon required a germination period of 8 days, a moisture content of 47% and temperature of 16°C. The models showed that the value of R2 was high and p- value was significant. Therefore it can be said that the model is highly significant. This project demonstrates that oat is an alternative cereal with potential to be used as raw material in malting and brewing purposesCon la ayuda de la metodología de superficie de respuesta, se estudió la influencia de tres variables del malteado (tiempo y temperatura de germinación, y grado de humedad) en la calidad de dos cultivares de avena (Avena sativaL.). Cada variable fue evaluada a tres niveles, de 6 a 8 días de germinación; temperaturas de germinación de 12, 15, o 18°C; y grados de humedad del 43, 45 ó 47%. Todos los análisis estuvieron basados en los métodos descritos por la EBC o por la MEBAK. Los cultivares, obtenidos de Nordsaat Saatzucht GmbH, Böhnshausen, Alemania, fueron de la cosecha del 2007. Se evaluaron una serie de atributos de calidad de la malta incluyendo extracto, límite de atenuación aparente, índice de Kolbach, α-aminonitrógeno, color, β-glucano y viscosidad. La optimización del malteado de la avena se realizó siguiendo las especificaciones de la malta de cebada, consideradas las más apropiadas en la industria de producción de bebidas para un buen procesado. Para el cv. Ivory, el programa de malteado óptimo se alcanzó a los 8 días de germinación con un grado de humedad del 46% y a 17°C. De manera similar, el cv. Typhon necesitó un periodo de germinación de 8 días, un grado de humedad de 47% y una temperatura de 16°C. Los modelos mostraron valores R2 altos y p significativos. Por lo tanto, se puede decir que el modelo es altamente significativo. Este proyecto muestra que la avena es un cereal con potencial como materia prima para el malteado y la producción de cerveza

Genotypic diversity of Saccharomyces cerevisiae spoilers in a community of craft microbreweries

In brewing, the yeast chosen to conduct the fermentation is one of the key factors that influences theflavor profile. Yeasts that are deliberately not under the control of the brewer are referred to as ?wild yeasts?.The growth of wild yeasts at any stage of beer production process can cause defects that negatively impactbeer quality. Wild yeasts belonging to the Saccharomyces genus present the greatest risk, given theirphysiological and morphological similarity to the inoculated yeast. The production of craft beer in AndeanPatagonia of Argentina has grown considerably and a large community of microbreweries co-exist. Most ofthese have strong interactions and share many raw material suppliers. They have not yet installed propermicrobial quality control strategies and wild yeast contamination is challenging. The aim of this article wasto genetically characterize for the first time a high number of S. cerevisiae wild yeasts isolated from craftbeer that originated from Andean Patagonia, and to study the incidence of S. cerevisiae var. diastaticuscontamination. The genetic distinctiveness of 32 wild Saccharomyces was determined using multiple real-timePCR systems and PCR-amplicon capillary electrophoresis of IGS2 region. All isolates were positive forSaccharomyces cerevisiae, and 66 % were var. diastaticus (STA1 positive). Intriguingly, a single STA1 positiveisolate was also positive for Saccharomyces bayanus/pastorianus/uvarum and deserves further investigation.Strain level typification showed a large diversity even in isolates from the same brewery and also permitted thedetection of well-established strains within single breweries. It also evidenced possible cross contaminationsamong breweries. This study provides the first insight into the genetic diversity and distribution of a large setof S. cerevisiae var. diastaticus in a community of microbreweries and provides important information on howto tackle this problem in the most efficient way and thereby help improve the quality of craft beer.Fil: Latorre, Mailén Angelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; ArgentinaFil: Hutzler, M.. Weihenstephan Institute; AlemaniaFil: Michel, M. Weihenstephan Institute; AlemaniaFil: Zarnkow, M.. Weihenstephan Institute; AlemaniaFil: Libkind Frati, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales. Universidad Nacional del Comahue. Instituto Andino Patagónico de Tecnologías Biológicas y Geoambientales; Argentin

Optimization of the malting process of oat (Avena sativa L.) as a raw material for fermented beverages

The influence of the three malting parameters (germination time, germination temperature, and degree of steeping) on the quality of two oat (Avena sativa L.) cultivars was investigated applying response surface methodology. Each predictor variable was tested at three levels, germination of 6 to 8 days; germination temperatures of 12, 15, or 18¿¿C; and degrees of steeping of 43%, 45% or 47%. All analyses were based on methods described in EBC or MEBAK. The oats used were obtained in 2007 from Nordsaat Saatzucht GmbH, Bohnshausen, Germany. A series of malt quality attributes were evaluated including extract, apparent attenuation limit, Kolbach index, ¿¿-aminonitrogen, color, ¿À-glucan, and viscosity. Oat malt was optimized based on barley malt specifications, which are considered appropriate in the beverage production industry for optimal processing. For cv. Ivory, the optimal malting program was achieved after 8 days of germination with moisture content of 46%, and at 17¿¿C. Similarly, cv. Typhon required a germination period of 8 days, a moisture content of 47% and temperature of 16¿¿C. The models showed that the value of R2 was high and p- value was significant. Therefore it can be said that the model is highly significant. This project demonstrates that oat is an alternative cereal with potential to be used as raw material in malting and brewing purposes.Con la ayuda de la metodologia de superficie de respuesta, se estudio la influencia de tres variables del malteado (tiempo y temperatura de germinacion, y grado de humedad) en la calidad de dos cultivares de avena (Avena sativa L.). Cada variable fue evaluada a tres niveles, de 6 a 8 dias de germinacion; temperaturas de germinacion de 12, 15, o 18��C; y grados de humedad del 43, 45 o 47%. Todos los analisis estuvieron basados en los metodos descritos por la EBC o por la MEBAK. Los cultivares, obtenidos de Nordsaat Saatzucht GmbH, Bohnshausen, Alemania, fueron de la cosecha del 2007. Se evaluaron una serie de atributos de calidad de la malta incluyendo extracto, limite de atenuacion aparente, indice de Kolbach, �¿-aminonitrogeno, color, �À-glucano y viscosidad. La optimizacion del malteado de la avena se realizo siguiendo las especificaciones de la malta de cebada, consideradas las mas apropiadas en la industria de produccion de bebidas para un buen procesado. Para el cv. Ivory, el programa de malteado optimo se alcanzo a los 8 dias de germinacion con un grado de humedad del 46% y a 17��C. De manera similar, el cv. Typhon necesito un periodo de germinacion de 8 dias, un grado de humedad de 47% y una temperatura de 16��C. Los modelos mostraron valores R2 altos y p significativos. Por lo tanto, se puede decir que el modelo es altamente significativo. Este proyecto muestra que la avena es un cereal con potencial como materia prima para el malteado y la produccion de cerveza

Archeochemistry reveals the first steps into modern industrial brewing.

A historical beer, dated to the German Empire era, was recently found in northern Germany. Its chemical composition represents a unique source of insights into brewing culture of the late nineteenth century when pioneer innovations laid the foundations for industrial brewing. Complementary analytics including metabolomics, microbiological, sensory, and beer attribute analysis revealed its molecular profile and certify the unprecedented good storage condition even after 130 years in the bottle. Comparing its chemical signature to that of four hundred modern brews allowed to describe molecular fingerprints teaching us about technological aspects of historical beer brewing. Several critical production steps such as malting and germ treatment, wort preparation and fermentation, filtration and storage, and compliance with the Bavarian Purity Law left detectable molecular imprints. In addition, the aging process of the drinkable brew could be analyzed on a chemical level and resulted in an unseen diversity of hops- and Maillard-derived compounds. Using this archeochemical forensic approach, the historical production process of a culturally significant beverage could be traced and the ravages of time made visible

Investigation into the potential of Lachancea fermentati strain KBI 12.1 for low alcohol beer brewing

In brewing research, non-Saccharomyces yeasts have gained attention in recent years, owing to their potential to influence the characteristics and flavor of beer. The Lachancea genus possesses an uncommon trait, the production of significant amounts of lactic acid during alcoholic fermentation. This trait could potentially be harnessed for brewing purposes, particularly for the production of low alcohol beer. In this study, the potential of Lachancea fermentati strain KBI 12.1 was investigated for the production of low alcohol beer in low gravity wort. KBI 12.1 was characterized for sugar utilization, hop sensitivity, phenolic off-flavor (POE) production, and propagation performance. Lab scale fermentation trials in diluted wort (6.6 degrees P) were conducted and compared to a brewers' yeast, Saccharomyces cerevisiae WLP001. Fermentations were monitored for lactic acid and ethanol production, pH drop, and sugar consumption. In the final beers, amino acid and free amino nitrogen (FAN) content were determined and secondary metabolites were quantified. Lachancea fermentati KBI 12.1 showed to be unable to utilize maltotriose. The strain exhibited no POF production, minor hop sensitivity, and excellent propagation performance. Amino acid and FAN consumption were much lower compared to that of the brewers' yeast. In the final beer fermented with KBI 12.1, the lactic acid concentration reached 1.3 g/L, giving the beer a sour taste. During sensory analysis, the beer was additionally described to have a fruity character. In conclusion, Lachancea fermentati KBI 12.1 proved to be a suitable strain for brewing purposes, with promising traits with regard to nonalcoholic and low alcohol beer brewing