Better beer is in the barley

A beer mug filled to the brim with grain sits on a rough wooden table, surrounded by a scattered pile of grain.

Better beer is in the barley

A genetic discovery in wheat may help produce superior barley and tastier beer
August 11, 2015

Beer foam stability and off-flavours may not be top of mind for this patio season’s revellers, but it is a concern for beer brewers. Fortunately for them, they have Surinder Singh of McGill University’s plant science department on their side. The PhD student is applying what he’s learned from a groundbreaking wheat project he worked on with CFI-funded researcher, Jaswinder Singh (not related), to identify good barley from bad barley. In more scientific terms, Surinder is working to pinpoint the genetic markers in barley that indicate whether or not it’ll germinate prematurely before harvest time so that farmers and brewers alike can be guaranteed good barley and a good brew.

If barley germinates before it has matured and is ready for harvest, it can’t be processed for beer. If it were, the beer would taste bad and it might be susceptible to mold and a nasty smell — not ideal for even the most novice beer connoisseurs. Germination, Surinder says, requires several environmental factors such as water, warm temperatures, soil and light.

Germination before harvest — what he calls pre-harvest sprouting (PHS) — is often triggered by rainfall or high moisture levels in the air during harvest time. The McGill team discovered that in wheat there are also epigenetic factors that could cause PHS. Epigenetics is the study of changes within a species caused by something other than DNA. “Epi” literally means “other” in Greek.

During the wheat project, Singh and Singh identified an important gene that acts as a switch to determine whether or not a plant will germinate when exposed to high humidity and excess rainfall or not. This switch is found in a gene called ARGONAUTE4_9.

The researchers used genomic and molecular imaging tools funded by the CFI to identify specific ARGONAUTE4_9 genes, and then compared the way that these genes are expressed in PHS-resistant versus PHS-susceptible kinds of wheat. This molecular marking is now being applied to barley.

Barley and wheat are genetically similar, distant cousins so to speak, so applying these markers to barley has proven successful. Surinder says once they’ve tested all of barley’s markers, they’ll advise farmers which barley is best for beer; that is, barley that doesn’t lie dormant or “stay asleep” for too long after it’s been harvested or sprout before harvesting. Singh, ironically enough, doesn’t drink beer but he’ll help himself to a few tasters once the job is done.

This story was originally published in March 2014.