Brewing with Unmalted Cereal Adjuncts: Sensory and Analytical Impacts on Beer Quality

Abstract

Brewing with unmalted cereal adjuncts can reduce the requirement for malting, thereby lowering costs and improving the overall sustainability of the brewing chain. However, substantial adjunct usage has technological challenges and the sensory characteristics of beers produced using high adjunct rates are still not fully understood. This study examined the impacts of brewing with unmalted barley, wheat, rice and maize at relatively high concentrations (0, 30% and 60% of grist) on the sensorial and analytical profiles of lager beer. Adjunct based beers and a 100% malt control were brewed at 25 L scale. A trained sensory panel (n = 8) developed a lexicon and determined the sensorial profile of beers. At 30% adjunct incorporation there was insignificant variation in the expected beer flavour profile. At 60% adjunct incorporation, there were some significant sensory differences between beers which were specific to particular adjunct materials. Furthermore, 60% adjunct inclusion (with correspondingly low wort FAN) impacted the fermentation volatile profile of the final beers which corresponded with findings observed in the sensory analysis. Developing an understanding of adjunct-induced flavour differences and determining strategies to minimise these differences will facilitate the implementation of cost-efficient and sustainable grist solutions.

Barley Protein Properties, Extraction and Applications, with a Focus on Brewers’ Spent Grain Protein

“…In certain countries, namely Germany, Switzerland and Greece, the purity law (‘Reinheinsgebot’) states that beer may only be made from water, malt, hops and yeast, so adjuncts are prohibited. Generally, adjuncts are used to reduce raw material cost and/or to add certain desirable qualities to the finished beer [ 50 , 51 ]. While they are predominantly cereal-based, sugar-based syrups can also be used.…”

“…A separate study by Glatthar et al (2005) investigated the use of un-malted triticale as a brewing adjunct and noted that the wheat and rye hybrid held great potential for use as a brewing adjunct. While adjunct addition levels vary widely, high levels of addition can present increased effects on sensory characteristics as well as technological difficulties, such as increased viscosity [ 51 , 53 , 55 ]. In a study by Yorke et al (2021), it was found that while 30% adjunct addition had little to no observable effect on beer characteristics, 60% addition presented increased sensory differences, low free amino nitrogen and dramatically altered the fermentation profile [ 51 ].…”

Buckwheat and Amaranth as Raw Materials for Brewing, a Review

“…Future studies are being considered to improve the malting conditions, especially for amaranth, to optimize technological processes and manufacturing recipes to improve the sensory characteristics of beer—the finished product [ 151 , 152 , 153 ]. This process requires concentrated and continuous research efforts and the coordination of all stakeholders for the effective implementation of relevant solutions with effects on the quality of the finished product [ 154 , 155 , 156 ]. Technological innovation takes into account technical and economic criteria, but also the acceptability of new assortments by consumers [ 8 ].…”

Brewing with Starchy Adjuncts: Its Influence on the Sensory and Nutritional Properties of Beer

“…When high adjunct levels are added, the brew functionality and processability of the mash must be achieved, and there must be no adverse impacts on the quality of the beer product [31]. The principal liability in terms of processability when non-malted adjuncts are added is the lowering of amylolytic, cytolytic and proteolytic enzyme activities in the mash, as these enzyme systems are excited and synthesised during the mashing operation.…”