Do You Need to Wash Bagged Lettuce?

To wash or not to wash bagged lettuce. That's the question that unleashed a Twitter and blogosphere firestorm after an off-the-cuff on-air comment on National Public Radio's "All Things Considered" suggested a second wash might help.

Food safety experts tend to disagree. If bacteria managed to survive commercial-grade washing in chlorinated water, chances are a trip under your tap isn't going to help, explained Brian Buckley, chef/instructor and food safety expert at the Institute of Culinary Education. On NPR's blog The Salt, they followed up the on-air slip with a post explaining the tenacity of E. coli, noting that not only is it difficult to remove or kill bacteria trapped below the surface of a lettuce leaf, but "there's a real risk that you'll end up adding bacteria to greens that were perfectly clean to start with: Your sink or cutting board may be dirtier than the lettuce."

The opposite is true, too. If the lettuce isn't clean, a wash under the faucet risks contaminating your sink and work surfaces where other food is prepared as drips and drops of water from the contaminated lettuce spread around the kitchen, said Buckley.

But it's hard to shake the feeling that washing your lettuce is doing some good. A Consumer Reports study in 2010 found that 40 perfect of lettuce sold in bags or plastic clamshells were contaminated with bacteria that could be harmful to your health. Just last week they issued a recall of Dole's Seven Lettuces. While their warning that another wash won't remove all bacteria from lettuce corroborates the advisories of most food safety experts, Consumer Reports still recommends it.

So what's a cook to do? The short answer: Don't bother. "It's either clean or it isn't and rinsing it at home won't remove anything but surface dirt," Buckley said. If bags of lettuce frequently appear in your shopping cart because you need all the kitchen shortcuts you can get, you might as well skip the extra step of a second--or in some cases third--wash.

The bottom line: Eating raw lettuce of all kinds comes with some risks. If swishing leaves of bagged greens around in cold water helps you sleep at night, knock yourself out. Just don't expect another cold water wash to keep a food-borne illness from knocking you down.

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