Drying barley a very risky proposition

Difficult harvest conditions could tempt farmers to take barley off tougher than usual and dry it.

While it's an understandable temptation, it's not the best management practice for growers aiming for malt selection, according to one grain storage specialist.

Dr. Noel White, of Agriculture and Agri-Food Canada's Cereal Research Centre in Winnipeg, says artificial drying - as opposed to natural aeration - is risky and can seriously harm the quality of barley samples.

"If you get it too hot you'll kill the germination," White says.

Germ is extremely important to maltsters, who sprout the grain before drying it to create malt for the beer industry. If the grain temperature rises above 43 degrees Celsius during the drying process, that will be enough to set back germination and could result in a rejected sample. The Canadian malting industry prefers that producers not artificially dry malting barley because of these quality concerns.

If the grain can be harvested close to dry, natural aeration is a far safer alternative to using artificial heat to dry barley.

"Definitely the emphasis is on aeration," White said. "If you can harvest it just a bit damp, aeration can bring the moisture level down about two per cent under the right conditions."

For best aeration drying results the air temperature must be above 10 degrees Celsius and relative humidity should be below 60 per cent. The volume of air fans can move will also determine how much drying will occur.

Once the grain is in the bin it's very important to monitor moisture levels to ensure the grain remains in good condition. If there are moisture pockets that haven't been eliminated by aeration, the grain may need to be turned.

If there's absolutely no choice but to dry the barley, there are some guidelines to follow that might allow the grain to still meet malt standards:

• Dry very slowly, and never allow the grain temperature to exceed 43 degrees Celsius.
• Use large volumes of air to prevent overheating.
• Continuous drying is preferable to batch drying.
• Leave the fans running after turning off the heat to equalize grain temperatures and prevent moisture migration.
• Use aeration systems to continue dropping the grain temperature after drying is completed. Aerate every time the outside air temperature drops 10 degrees.
• Turn the grain if necessary, but be very cautious when you do. Excessive handling can result in peeled and broken kernels. When running augers make sure they're full or reduce the auger speed.

Because malt barley is so sensitive to drying, farmers should consult with their selector before they attempt the process.

This article appeared in the September 2004 issue of Go Malting!, a newsletter of the Canadian Wheat Board.