“Leafy greens have been related to foodborne outbreaks because they are consumed without a process that can kill microorganisms after they are harvested from the field,” says Francisco Diez-Gonzalez, PhD, the director of the Center for Food Safety and a professor of food science and technology at the University of Georgia in Griffin.
While no cleaning method can completely eliminate every single harmful germ, experts say proper selection, washing, storage — and for some hearty greens, blanching — can help reduce your risk of foodborne illness.
Step-by-Step Guide to Washing Salad Greens Safely
Step 1: Prepare your space. Before handling your greens, wash your hands, countertops, cutting boards, and knives with hot soapy water to help prevent cross-contamination.
Step 2: Soak and swish, then rinse under running water. If your greens are especially dirty or gritty, place them in a clean bowl of cold water and gently swish them to loosen particles. Lift the leaves out of the water, then rinse each leaf thoroughly under cool running water to remove any remaining dirt, debris, and microorganisms from the surface.
Step 3: Dry thoroughly. Remove as much excess moisture as possible using a clean salad spinner or fresh paper towels. This helps clear any remaining dirt and microbes and also slows spoilage during storage.
How to Blanch Leafy Greens
“Blanching is normally done as a precursor to freezing,” says Martin Bucknavage, a senior food safety and quality specialist at Penn State University in State College. “It sets the color and destroys the enzymes that would cause the product to turn to mush during freezing and thawing,” he says. Blanching also destroys germs, “so it does have a sanitary function,” he adds.
Step 1. Briefly immerse vegetables in boiling water.
Step 2. Immediately transfer to an ice bath to stop the cooking process.
Experts note that blanching works best for sturdy greens that can withstand brief cooking, such as spinach, kale, Swiss chard, and collard greens. “It is not normally recommended for leafy greens such as [delicate] lettuce because of the damaging effect of heat on the crispiness and flavor,” says Diez-Gonzalez.
What Doesn’t Work to Reduce Food Poisoning Risk
Plenty of home remedies promise to remove germs from leafy greens, but food safety experts say many of them offer little benefit — and some may even increase your risk.
- Skip vinegar, baking soda, and DIY produce washes. There isn’t enough evidence to recommend these methods over thoroughly rinsing produce under cool running water. “Baking soda is largely ineffective to increase the effectiveness of washing with plain water,” Diez-Gonzalez says.
- Don’t use soap, bleach, or household cleaners. Fresh produce can absorb residues from these products, which shouldn’t be eaten and may cause illness. “These chemicals will be picked up in the leaf structure and will be there when consumed. Just not a good idea,” says Bucknavage.
- Don’t rewash “triple-washed” greens. Rewashing these items won’t make them safer and could actually introduce new bacteria through cross-contamination. “It really will not provide any further reduction, and will just add more moisture to the product — reducing storage time,” Bucknavage says.
How to Safely Select and Store Salad Greens
Minimizing contamination starts before you bring your produce home. Experts recommend these simple tips.
- Choose fresh, undamaged greens. Look for leafy greens that are crisp, brightly colored, and free of excessive bruising, sliminess, or signs of decay, Bucknavage says. Damaged leaves spoil more quickly, creating more opportunities for bacteria to grow.
- Keep produce separate from raw meat. Cross-contamination is one of the easiest ways for harmful bacteria to spread. Keep leafy greens away from raw meat, poultry, and seafood in your shopping cart and grocery bags, Bucknavage says.
- You don’t need to avoid bagged salads — but do inspect them carefully. Although bagged greens have occasionally been linked to foodborne illness outbreaks, experts don’t recommend avoiding them altogether. Instead, choose bags that are refrigerated, cold to the touch, and free of excess moisture, damaged packaging, or expired “use by” dates. “If you’re concerned and want control over washing your own produce, buy the unprocessed product and wash it yourself,” Bucknavage says.
- Don’t judge safety by where produce was grown. Both domestic and imported produce must meet food safety standards, so a product’s country of origin is not on its own a reliable indicator of safety. “Some types of both domestic and imported produce have been implicated in foodborne disease outbreaks, but there is no conclusive evidence that indicates that one is safer than the other,” Diez-Gonzalez says. Instead, he recommends paying attention to public health advisories and avoiding products that have been recalled.
“If you are in one of the harder hit regions of an outbreak, I would consider avoiding the items that the state has identified as a likely source — especially for those who are most at risk,” Bucknavage says. “If you are overly worried or are at risk due to health issues, consider switching away from the type of product being investigated until you feel more comfortable.”
