On Some Farms, Washing Machines Give Leafy Greens a Spin

Next time you inspect your salad greens to make sure they look clean, consider this: Researchers are trying to determine if drying leafy greens using the spin cycle of a retrofitted washing machine is safe.

Some farmers use the method instead of expensive, commercial-grade spinners to dry leafy greens after they’re washed. But it’s not clear using a converted washing machine is safe.

“This has been a common practice among small producers of greens,” said Amanda Kinchla, an associate professor of food science at the University of Massachusetts (UMass) Amherst Extension. “There are no regulations against this, but there is no data right now on the risk.”

Bacteria and grime could accumulate if farmers don’t know the best ways to spin the greens and clean the washing machines, according to Andrew Chamberlin, an agricultural engineering technician at the University of Vermont (UVM Extension).

“We are trying to share best practices for food production,” he said in a UMass news release.

One example of a best practice is to place the greens in baskets that fit inside the machine. This reduces the points of contact and the risk of contamination, compared with putting the greens directly into the washer, Chamberlin explained.

Based on his instructions, the UMass researchers have converted four washing machines to assess how leafy green contamination may occur, what germs are present, and how best to safely maintain, clean and sanitize the machines.

“We are examining whether the spin cycle on a washing machine has any more risk than commercially available, post-harvest leafy greens spinners,” said Kinchla, who is also co-director of the Northeast Center to Advance Food Safety in Bennington, Vt.

Her team will try to replicate as closely as possible the farmers’ practices and the environment and conditions in which they’re cleaning and drying the greens.

The goal is to develop guidelines for the safest and most effective use of a washing machine to spin-dry greens. “That would alleviate concerns from regulators, and avoid conflict between producers and regulators,” Kinchla said.

More information

Consumer Reports has more on leafy greens.