Colorado State University
Understanding Effects of Malt Storage on Beer Chemistry and Flavor Using a Metabolomics Approach
The goal of this project is to determine effects of malt storage on beer chemistry and flavor. According to long-held beliefs in the malting and brewing industries, malt should be “aged” for at least 3 weeks for reasons that remain unclear and unpublished. Aging, even under proper storage conditions, is known to be affected by oxygen, leading to lipid oxidation (rancidity), staling, and decreased flavor (Vanderhaegen, Neven, Verachtert, & Derdelinckx, 2006). Further, recent studies have validated a contribution of malt genetics and metabolites to beer flavor, and therefore it is timely to determine if and how malt storage can impact this area of research. Previous metabolomics analysis in our laboratory demonstrated chemistry and the corresponding sensory can differ based on storage. We therefore designed a project to investigate the contribution of storage to malt chemistry, aroma, and effects on beer flavor. The project is divided into two phases. Phase 1 is comprehensive metabolomics and sensory of malt. For Phase 2, we will perform a similar comprehensive metabolomics analysis of beers brewed from the commercial malts, comparing profiles of fresh and aged (n = 20 beers) made from the same malts. We will associate the data to quantitative sensory analysis. This experiment will help achieve the long-term goal of our collaborative research to develop chemical targets to evaluate malt for brewing quality and flavor. An important outcome of this research includes clarifying molecular foundations for the practice of aging malt and describing the potential for malt freshness impact on beer flavor.
Project Objectives
- Perform metabolomics analysis of 20 beers, from 10 malts both fresh and aged.
- Integration of sensory and chemical traits from beer and malt; analysis and interpretation of data Experimental design.
The experimental design is n = 10 malts * 2 storage conditions = 20 beers. Malts to be utilized are currently TBD but will include a variety of base and specialty malts commonly used by the brewing industry (i.e. pale, crystal, and chocolate). Malting will be conducted by Colorado Malting Company, as per protocol for each malt. Fresh malts will spend no time under storage conditions. Aged malts will have been aged for 3 to 6 months (to simulate the time malt is supposed to be “held” until use). Malts will have been stored under ambient (not refrigerated) conditions, in order to simulate typical brewery warehouse storage situations. Beers will be brewed, as per Colorado Malting Company recipes and protocols at the Colorado Farm Brewery (Alamosa, CO), and packaged into bottles for transport. Beers will be brewed into the style specific to the malt while adhering to parameters that include: IBU < 15, with no specialty hops; ABV < 6.0%, and utilizing only yeast specific to the style of beer being brewed. The 20 commercial beers will be transferred to chemical analysis vials, flash frozen in liquid nitrogen, and stored at -80 °C until chemical profiling can be performed.
Principle Investigator
Harmonie Bettenhausen
