“Damp” canola may not be safe, even if cold

December 4, 2019 - Issue 30

Freezing tough (10 to 12.5% moisture) or damp (over 12.5%) canola by running cold air through the bin can be a short-term storage solution for canola that couldn’t get dried before winter…but check that canola regularly. This is not as safe as you might think.

The Canola Council’s Clint Jurke shared this report last week: “We put some 15% moisture canola into a 3,000-bushel bin at -5°C about four weeks ago. We moved it on the weekend because it started to heat already.”

On Twitter recently, a Manitoba farmer reported on canola testing 13% when frozen, but when thawed, the actual moisture was so high the tester couldn’t read it. (Note: This could be a testing issue. Keep reading for tips on how to thaw a sample for accurate testing.)

Management messages are: (1) Moisture testers are not designed to provide an accurate reading on frozen grain, and (2) canola bins in this situation are at higher risk for spoilage, even in the winter.

In a Manitoba webinar last week, NDSU storage researcher Kenneth Hellevang had this tip to avoid moisture tester error: Put the sample in a sealed container (to allow the sample to come to equilibrium), bring it inside and wait 6 to 12 hours before testing. “The meter is fooled by the condition on the outside of kernels,” he says.

On “freeze drying”. During the webinar, Hellevang was asked about the concept of “freeze drying” grain – getting it so cold that it “dries”. He gets this question a lot and his simple answer is that the benefit, if any, will be minimal and not enough to make any difference to risk. He uses corn as an example. Corn left out in the field over winter will see some moisture removal…say from 24% down to 21% or 22% because wind provides “hundreds of CFM/bu”. But for grain in the bin, he says “it might appear that you’re drying, but it will be very slow.” It isn’t worth the energy you put into it, he says. If it “appears” that grain is drying, reference the previous paragraph on moisture meters and frozen grain.

The archived webinar with Hellevang and PAMI storage researcher Charley Sprenger, is posted here. Manitoba Corn Growers also has PDFs of the slides. Kenneth Hellevang Charley Sprenger

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