As climate stress drives barley protein levels higher and craft brewers face mounting pressure to deliver consistent, shelf-stable beer, the Brewers Association (BA) is making a direct ask of the people who grow the grain: breed for lower protein.

The BA recently sent a memo to the American Malting Barley Association (AMBA) calling for further revisions to their Guidelines for Malting Barley Breeders, a set of quality targets that guide barley breeders toward varieties that meet the needs of end users — craft brewers like you. Here’s what changed, why it matters, and what the BA is pushing for next.

A Brief History: How Craft Brewers Changed Barley Breeding

Early craft brewers recognized the challenges of such limited options in the domestic barley supply, and as the industry grew their voices began to be heard. These rumblings culminated with the 2014 publication of the Brewers Association’s white paper Malting Barley Characteristics for Craft Brewers, which highlighted the “malt supply mismatch as a potential impediment” to the success of the craft brewing industry. The document was aimed towards all members of the supply chain but specifically highlighted the challenge of using contemporary barley varieties for all-malt brewing and called for the development of those that met the unique needs of craft brewers. The message was well received and that same year AMBA expanded their guidelines to include a category specifically for all-malt brewing (distilling specific guidelines came later). As a result, barley varieties geared for all-malt brewing gained prominence and now plays a larger role in breeding programs across the country.

The 2025 Update and Why More Is Needed

Early in 2025, the guidelines were updated once again to the further benefit of craft brewers, most notably by lowering the grain protein target and other metrics associated with more moderate modification. However, despite these wins, the reality is that various agronomic factors are placing pressure on malting barley while a more dynamic beer market is forcing brewers to place increasing emphasis on beer quality and shelf stability. The recent updates to the All-Malt category showed that AMBA is committed to the needs of craft brewers and thus the timing was right for a new explicit directive from the BA to add further guidance of the needs of craft brewers. A working group within the BA Supply Chain Subcommittee was formed to evaluate the current guidelines and draft a memo to AMBA to encourage further revisions. This group represented a broad swath of BA membership: from brewpubs and taprooms to large national brewers producing over one million barrels across multiple facilities. Over a number of months, they discussed the guidelines, their respective challenges, and their desires for the next generation of barley varieties.

What Craft Brewers Are Asking For

The main theme from the group was the need to prioritize lower protein barley varieties that express more moderate modification patterns. There is a positive correlation between heat and/or drought stress and grain protein, and the outlook is that the average protein will continue to rise. The goal is to encourage breeders to select low-protein material that is more resilient to abiotic stress and can thrive even under dryland conditions. These desires arise from the challenges of working with high-protein barley and the impact of the artifacts of proteolysis on flavor stability of all-malt beers. The consensus was to encourage selection of barley varieties that modify more gradually and thus have lower free-amino nitrogen (FAN) and other short chain peptides that negatively affect beer flavor. The group proposed expanded ranges for β-glucan, FAN, and the soluble to total protein ratio (S/T or Kolbach Index) in order to broaden the breeder’s selection pool.

• Barley Protein: further reduce upper limit to 11.5% 
• β-glucan: raise upper limit to 150 mg/L 
• FAN: reduce lower limit to 120 mg/L 
• S/T: reduce the lower limit to 36% 

For a deeper understanding of how barley quality parameters affect modification and subsequently flavor stability, refer to the references below.

Putting DMS on the Radar

In addition to changes to metrics, the most recent round of guideline updates included mention of di-methyl sulfide (DMS) and specifically it’s precursor in malt (S-methylmethionine or DMSp), but only in the general comments. This is a great step forward in promoting breeders to be aware of this brewer concern but more intentional direction is warranted. It is understood that this trait is a measurable and heritable phenotype and hope this note encourages further research on the effect of genetic and environmental factors of DMSp formation in relation to other proteins and peptides. Further, including DMSp data on breeding lines would be beneficial in making selections and the hope is that eventually quantification of DMSp will be included in line evaluation and becomes more commonly reported on standard certificates of analysis.

The Road Ahead

The craft brewing industry thrives on collaboration across the supply chain and continued engagement between brewers, maltsters, growers, and breeders is critical to ensuring collective success. The BA will continue to communicate craft brewers’ specific quality requirements for barley varieties to AMBA that will allow the continued production of the highest quality and flavorful beers.

Additional Resources

• Malting Barely Characteristics for Craft Brewers
• The Effect of Malt Quality and the Malting Process on Beer Flavor Stability
• The Past, Present and Future of Malting Barley for Craft Brewers
• Origins of Malt Flavor and Malt Varieties for Craft Brewers
• The Six-rowification of North American Two-row (Parts 1&2: history, how & why)