Development and quality assessment of low-cost benchtop malting protocol for laboratory-scale barley (Hordeum vulgare L.) malt quality evaluation

Abstract

High-quality malt is influenced by three primary factors: barley genotype, environmental conditions, and malting process. To effectively evaluate malting barley (Hordeum vulgare L.) breeding material and assess how environmental changes influence malt quality, it is essential to have laboratory-scale malting methods that can produce malt similar to that produced by commercial malting operations. However, existing laboratory-scale malting procedures often require large quantities of grain, specialized equipment, and are costly. To overcome these challenges, we developed a small sample-scale benchtop malting method utilizing standard laboratory equipment and components available at hardware stores. We validated the method by conducting standard malt quality tests including diastatic power, α-amylase activity, total malt protein, and wort composition (soluble protein, wort soluble/total malt protein, β-glucan, free amino nitrogen, and malt extract). Our findings indicate that the benchtop malting method yields quality metrics comparable to those obtained from established small-scale and full-scale malting protocols. Furthermore, a key innovation of this system is the use of separate Erlenmeyer flasks for malting each sample. Unlike conventional shared malting systems, this design enables precise measurement and comparison of treatment effects across samples malted simultaneously. This reliable, low-cost, and efficient method provides a valuable tool for screening malt quality traits in breeding lines with limited sample sizes and for testing malting regimes aimed at improving malt quality and efficiency. Additionally, it offers an accessible solution for producing high-quality, research-scale malt in laboratories without dedicated quality assurance facilities.