RESUMEN

The removal of husks before the mashing process, also known as the Kubessa method, is an established brewing practice often positively associated with smoothness and better flavor-stability of beer. Empirical evidence on the effect of the Kubessa method on beer, however, has been lacking. Similarly, our study's comprehensive analysis of established brewing attributes revealed that traditional methods do not fully capture the impact of husk separation in beer brewing. Conclusive evidence of the Kubessa method's impact on beer aging chemistry was obtained through ultrahigh resolution mass spectrometry (FT-ICR-MS), revealing intricate molecular details inaccessible to conventional analytical techniques. The compositional information on thousands of molecules in Kubessa beer was resolved and compared to whole malt mashing. Machine learning algorithms applied to aging experiments identified over 500 aging-related compounds inhibited by husk separation. Complementary Time of flight mass spectrometry (ToF-MS) coupled with chromatography further confirmed that the mashing of husks introduces sulfur-containing lipid compounds. These significant differences in the beer composition provide valuable insights for further investigation into the staling protective effect of husk-separation (Kubessa process) during beer production, as empirically demonstrated in this work.

Asunto(s)

Cerveza , Manipulación de Alimentos , Espectrometría de Masas , Cerveza/análisis , Manipulación de Alimentos/métodos , Gusto , Factores de Tiempo , Grano Comestible/química

RESUMEN

Brewing is a highly complex stepwise process that starts with a mashing step during which starch is gelatinized and converted into oligo- and/or monosaccharides by enzymes and heat. The starch is mostly degraded and utilised during the fermentation process, but grains and hops both contain additional soluble and insoluble complex polysaccharides within their cell walls that persist and can have beneficial or detrimental effects on the brewing process. Previous studies have mostly been restricted to analysing the grain and/or malt prior to entering the brewing process, but here we track the fates of polysaccharides during the entire brewing process. To do this, we utilised a novel approach based on carbohydrate microarray technology. We demonstrate the successful application of this technology to brewing science and show how it can be utilised to obtain an unprecedented level of knowledge about the underlying molecular mechanisms at work.