Overwintered canola contains higher free fatty acid levels, but can still produce acceptable seeds

Quality of overwintered canola

In 2019, many farmers were unable to finish harvesting much of their canola after early snowstorms buried crops that remained in fields. Dr. Véronique Barthet, Program Manager for Oilseeds Research at the Canadian Grain Commission, and her team collected and evaluated the quality of over 100 samples of overwintered canola that was planted in 2019 but not harvested until spring and summer 2020.

The research team discovered that the overwintered canola samples contained higher oil content and higher than normal free fatty acid (FFA) levels compared to autumn-harvested samples. However, overwintered canola could still provide suitable quality seeds as there were samples of the top grade with acceptable FFA levels.

The overwintered canola samples were submitted by producers and processors from across western Canada. The majority came from northern Alberta, which was the hardest hit area. Dr. Barthet and her team found that:

  • 27.4% of the samples were graded No. 1
  • 34% of the samples were graded No. 2
  • 20.8% of the samples were graded No. 3
  • 17.9% of the samples were graded Sample

The research team graded and analyzed the samples for parameters that define canola quality, including protein, oil content and FFA. FFA was a key concern because of its negative impact on oil quality. They re-analyzed FFA content after the samples were in storage for two months and found that FFA had increased in storage, even though the samples were stored in low moisture conditions.

While some of the overwintered canola samples were of good quality and could be processed, it’s recommended that all overwintered canola be processed as soon as possible to limit the effects of FFA content and oxidation on oil quality.


“Grain handlers and processors had concerns about free fatty acid levels in overwintered canola crops. We were able to determine that some of these samples could still be processed into good quality oil as long as they’re processed as soon as possible.”

Dr. Véronique Barthet
Program Manager, Oilseeds, Grain Research Laboratory
Dr. Véronique Barthet

For more information:

Quality of the spring harvest (overwintered) western Canadian canola

Date modified: