Relating agronomic practices to malt quality

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More is better when it comes to seeding malting barley, says Kelly Turkington, a research scientist with Agriculture and Agri-Food Canada at Lacombe.

Turkington described research on growing better malting barley at a joint meeting of the Alberta Canola Producers and the Alberta Barley Commission in Lacombe last month.

“The overall objective is to look at agronomic practices and improve the quality of the malting barley that we’re growing in Canada,” said Turkington. The project is designed to look at the impact of various agronomic practices on malt quality, and is the first of its kind in North America.

Malting barley varieties account for 70 per cent of Prairie barley acreage, but Alberta’s situation is a bit different from other provinces as half the barley grown in the province is feed varieties grown for the livestock sector. About 20 per cent of the barley grown in Alberta is selected for malting each year, but Turkington sees that increasing.

“If we start looking into the future as far as demand from China and Japan and other parts of the Far East, we’re probably looking to increase our malting barley production by about 5 to 10 per cent to meet future demand,” he said.

Turkington listed many of the qualities that make barley more acceptable to the maltster and brewer.

“Basically what you’re doing in the malt house is you’re removing cellular barriers in the grain and you’re stimulating the production of enzymes which convert into complex carbohydrates like simple sugars which can then be used by the processors,” said Turkington.

He says maltsters and brewers are looking for specific qualities. They are interested in malt extract, which defines the amount of fermentable sugars available for the yeast. “The more malt extract you have in your malt barley, the more beer you have being produced per unit of malt barley.”

Maltsters also look for low protein. which means a higher level of carbohydrates in the seed and a higher malt extract. Ideally, barley used for malting should have about 11 to 12 per cent protein. Low levels of beta glucan are also desirable, since the substance can gum up filters used in the brewing process, resulting in more labour and maintenance for the maltster.

Another desirable quality is friability, which indicates how well the endosperm breaks down. “The higher the friability, the better,” said Turkington. “It means there are more simple sugars available for brewing.”

AGRONOMIC FACTORS

Factors being examined in the Agri-Food study include seeding rate, seeding date, stubble type, and fungicide application. Several locations across Alberta, Saskatchewan and Manitoba are conducting a number of trials, so a variety of geographic areas and environmental conditions can be tested. Seeding rates between 100 to 500 seeds per square metre were tried. The seeding rate trials found about 300 seeds per square metre is the optimal seeding rate over a wide range of environmental conditions, said Turkington.

The trial was conducted using both AC Metcalfe and CDC Copeland barley varieties. Increased seeding rate resulted in more competition between the plants and a significant reduction in plumpness in several of the five locations involved in the trial.

“The advantage of increasing the seeding rate is that as we increase the seeding rate we see a reduction in the maturity rate,” said Turkington.

As the seeding rate was increased, there was a significant rise in malt extract yield, a reduction in beta glucan and a significant increase in friability and homogeneity. However, increased seeding rate may result in a kernel with reduced plumpness.

The research team emphasized the ideal seeding rate depends on the kernel weight and the barley variety.

“The ideal seeding rate was about 210 plants per square metre. The problem is that when you plant 210 seeds per unit area, you’re not going to get 210 plants coming up. So maybe you need to bump up your seeding rate in order to meet your target plant population,” said Turkington.

Seeding depth is another factor. “As we increase our seeding

depth, we need to bump up our seeding rate in order to meet our target population of 210 plants per metre squared,” he said.

Tests where researchers increased nitrogen resulted in increased protein to a level which may be unacceptable to maltsters.

About the author

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Alexis Kienlen

Alexis Kienlen lives in Edmonton and has been writing for Alberta Farmer since 2008. Originally from Saskatoon, Alexis is also the author of two collections of poetry, a biography, and a novel called "Mad Cow."

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