Is washing your produce a waste of time?
It's an unconscious act for many: Before you eat raw produce, rinse it off. But what would happen if we didn't? Probably nothing, food experts say.
While reflexively washing a radish does cut down your risk of illness, experts said that risk is small to begin with. And what's more, they stress that rinsing does not clean all produce equally.
Randy Worobo, a food microbiology professor at Cornell University, and Linda J. Harris, chair of the food science and technology department at University of California-Davis, shared on how to best wash produce, and why our best efforts may not matter much.
"Washing isn’t nearly as effective as cooking for reducing bacteria," Harris said. "But it can play a role when you want to eat your produce fresh."
Produce less risky than imagined
Most of that bacteria that glom onto your fruits and vegetables are harmless, Harris said, causing your kumquats to spoil but not actually making you sick.
Both Harris and Worobo agreed that the risk of illness from eating raw produce is low "but not zero." And while 85% of Americans worry about pesticides, according to a 2015 Consumer Reports study, federal studies show pesticide residues in Americans' foods are "well below" safety standards.
"The use of pesticides in the U.S. is strictly controlled, which is aimed at having low levels of pesticides in the finished produce," said Worobo, though "washing with just water will remove the water soluble pesticides that may be there."
Pathogen-infested produce has been linked to outbreaks of salmonella, E. Coli and listeria, Harris noted. The Centers for Disease Control lists multi-state outbreaks online, including one from packaged salads last year and cucumbers and bean sprouts the year before that.
But the most crucial steps to safeguarding against a nasty salmonella strain take place before those bean sprouts even hit your bag. The industry's overall strategy aims to reduce product-related illnesses during the farming, harvesting and packaging processes, she said.
Here's how to wash
Still, studies show 90% of any remaining pathogens are removed after rinsing, Worobo said.
Why clean a vegetable's surface, though, when you can remove it?
"I would probably recommend just peeling it," he said, a method he admitted works better on turnips than tomatoes.
If rinsing's the best option, here's what Harris recommends: Rub the fruit or vegetable as you wash it under tap water and then dry it with a clean paper towel. The physical acts of rinsing, rubbing and drying act in tandem to remove bacteria, Harris said, provided the towel is totally clean.
How long should you rinse, though? That varies, Worobo said. Aim for two minutes of water contact, going longer for items with more surface area like leafy greens. Tomatoes, with their smooth surface, clean relatively easily, he said, while "cantaloupes are a bear." Their netted rinds make perfect hiding spots for bacteria, Harris said.
"For items like raspberries, its very difficult to apply any physical pressure and the water tends to bead on the surface so washing is a challenge and not particularly effective," she said.
When we make it worse
Highly publicized outbreaks aside, one item you should never worry about washing is bagged greens such as spinach or salad advertised as pre-washed, Worobo and Harris said, as your kitchen's more likely to contaminate them than you are to further clean them.
"Best to go straight from the bag to the salad bowl," Harris said.
And if you really want to keep your produce clean, Worobo said, avoid cross-contaminating it with other foods.
“What you never ever want to do is go from handling raw meat and using the same knife or tongs or hands to prepare a salad," he said. "That's the best thing a consumer can do."
Follow Josh Hafner on Twitter: @joshhafner
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