Research Summaries
Most published research on GF malting and brewing is written for specialists and sits behind paywalls. These summaries extract the practically useful findings and explain what they mean for producers and informed consumers.
Each summary covers one research area, what was studied, what was found, and what the practical implication is. For full citations and links to source material, see the Source Library.
Sorghum Malt Quality and Diastatic Power
What was studied: Multiple research groups have examined how steeping duration, germination time, and kilning temperature affect diastatic power in malted sorghum. Studies from South African and US labs have produced the most practically useful data.
Key finding: Sorghum DP is highly cultivar-dependent. Diastatic varieties can reach 60–80°L under optimized conditions; non-diastatic varieties produce near zero regardless of malting protocol. Germination temperature (typically 18–22°C) and duration (4–5 days) significantly affect final DP.
Practical implication: Cultivar selection is the first and most important decision in sorghum malting for brewing. Process optimization matters, but it cannot compensate for an inherently low-DP variety.
Millet Malting Performance
What was studied: Research from multiple institutions has compared finger millet, pearl millet, and proso millet as base malts for GF brewing.
Key finding: Pearl millet and finger millet both produce adequate DP for GF brewing under proper malting conditions, with some varieties exceeding 100°L. Millet generally gelatinizes at lower temperatures than sorghum, which simplifies mashing.
Practical implication: Millet is in some respects a more brewable base malt than sorghum — higher DP ceiling, lower gelatinization temperature, and less need for exogenous enzymes. Its growing commercial availability makes it increasingly relevant for GF producers.
GF Beer Flavor Chemistry
What was studied: Flavor compound analysis comparing GF beer (sorghum and millet-based) to barley-based beer, with particular attention to off-flavor precursors.
Key finding: GF beers show different aldehyde and ester profiles compared to barley beer. Certain sorghum varieties produce higher levels of specific aldehydes that contribute "grainy" off-flavors. Yeast strain selection and fermentation temperature management significantly affect the flavor outcome.
Practical implication: GF beer flavor is controllable — but requires deliberate management of yeast strain, fermentation temperature, and raw material selection. The flavor problems associated with early GF beers were largely process failures, not inherent grain limitations.
Source Notes
Summaries based on published peer-reviewed research. Full citations available in the Source Library.