What makes the perfect pint of beer? Could it be the hops, the skill of the brewer or could the type of barley be more important than previously thought?
New research has re-examined the role barley may play in flavouring beer and found that Australian barley could be much more flavourful than barley from the United States.
It has long been thought that much of the flavour of beer comes from the hops and that barley just provides the malt "skeleton" for the beverage.
However, University of Adelaide's Sue Stewart says she has discovered flavour compounds in Australian barley that could be affecting how the beer tastes.
"Australian varieties have far more flavour compounds than the US varieties, probably in the order of about nine to one," she said.
"We ended up finding about 106 significant flavour compounds, which we're now looking into.
"It was very insightful to show that the Australian varieties contain so many more flavour compounds than varieties from China, Canada and France."
Could anyone taste the difference?
Coopers Brewery sponsored the research in the hope it would be able to match particular barley varieties to different clients.
Malting manager Doug Stewart said Chinese beers tended to have less flavour than Australian beers and that recently the flavour of Australian barley had been an issue.
"The Chinese beers are very subtle beers. They're made with quite low hopping levels and because they're a very clean flavour the Chinese brewers were saying they could tell a difference between the Canadian varieties, which they preferred to the Australian varieties," he said.
"What Dr Sue Stewart's research … has shown is that they're probably right; that these Canadian varieties are very clean in their flavour profile whereas the Australian varieties are more robust.
"Of course, it's horses for courses. If you're making a craft beer you probably want something more robust."
Dr Doug Stewart says since the Coopers Brewery supplies a lot of malt to craft breweries, this research could enable it to match malts with different breweries depending on what sort of beer they are going for.
He had also noticed a difference in the flavours of barley himself.
To test her results, Dr Sue Stewart gave Dr Stewart and the other members of Coopers Brewery testing board some wort, which is unfermented beer, made with different varieties of barley.
Dr Stewart said he was shocked they could tell a difference.
"We were just presented with cuts of wort… and we weren't told where they came from," he said.
"The panel correctly ranked them from Australian, Canadian and Chinese varieties in descending order of flavour.
"There's obviously those malty and biscuity notes but there were also grassy notes and some more musky notes, so more like mushrooms.
"We were quite surprised we could pick up these compounds."
Dr Stewart says the scientific community still knows very little about what role barley plays in beer flavour.
"Only about five years ago a group in Oregon State University started looking into whether the malt contributes more than just the sugar backbone," she said.
"So there's only our group and that group in the world that are doing this at the moment.
"It's a very new area and I think there will be more in the future."
