Most people rinse apples under the tap, but a study found plain water barely touches pesticide residue; a baking-soda soak removed up to 96% of it

If your entire pesticide-removal strategy is just to hold an apple under the kitchen tap for ten seconds, you’re not alone, and you’re also not doing much. According to a 2017 study published in the Journal of Agricultural and Food Chemistry and led by food scientist Lili He at the University of Massachusetts Amherst, a baking-soda soak removed surface pesticide residue from apples far more effectively than plain tap water or the food industry’s standard bleach wash in under 15 minutes. For a generation raised on grocery-store produce and DIY kitchen hacks, this is the kind of study that actually changes what you do at the sink.

The science behind the soak
In the same study titled ‘Effectiveness of Commercial and Homemade Washing Agents in Removing Pesticide Residues on and in Apples,’ the team coated organic Gala apples with two common pesticides, thiabendazole, a fungicide, and phosmet, an insecticide, at a rate of 125 nanograms per square centimeter, roughly what might be applied on the farm, and let the residue sit for 24 hours before washing.

They tested three cleaning methods: rinsing with tap water, soaking in a Clorox bleach solution (the two-minute wash used after harvest by commercial processors), and soaking in a sodium bicarbonate (baking soda) solution. The team used a laser-based imaging technique called surface-enhanced Raman scattering, combined with liquid chromatography tandem mass spectrometry, to track exactly where the pesticides ended up.

The baking-soda solution was the winner by a big margin. After 12 minutes in the solution, about 80% of the thiabendazole was removed from the surface, and 96% of the phosmet was removed after 15 minutes, according to an analysis by Chemical & Engineering News. By contrast, the same washing times produced far more residue in the tap water and bleach wash.

Why the standard bleach wash falls short
That bleach detail is worth sitting with because it's not some fringe method; it's standard industry practice. Most commercially processed produce in the US undergoes a brief chlorine wash after harvest, primarily to kill bacteria and mold, not to remove pesticides. That standard two-minute bleach dip isn’t an effective way to fully remove pesticide residue, and treating it as a safety net is a mistake, the study says.

Baking soda worked better because of basic chemistry. Sodium bicarbonate solution is alkaline. Most pesticide compounds are unstable at alkaline pH, which breaks them down and helps wash them away. The chemical breakdown of the residue, combined with the soaking and rinsing, accomplished what plain water alone could not.

The part a soak can't fix
Here's the catch, and it’s important if you’re imagining a magic fix: not all of the pesticide remained on the surface. In those 24 hours, the study found that about 20 percent of the applied thiabendazole and 4.4 percent of the applied phosmet had already entered the apple’s peel and flesh. Thiabendazole, a “systemic” pesticide that moves through plant tissue, penetrated the peel about four times deeper than phosmet, which tends to remain on the surface. There was no eliminating that internalized residue, not even by washing with baking soda.

The researchers were clear-eyed about this trade-off. The study showed that peeling the apple would remove most of the penetrated pesticide, but would also strip away the fiber, antioxidants, and other bioactive compounds concentrated in the skin, not a clean win.

Should you actually be worried?
It’s easy to get lost in a scary headline, so context matters here. According to the USDA's Pesticide Data Program, which tests thousands of food samples every year, more than 99% of produce sampled comes in below EPA residue limits, suggesting a low acute health risk from typical exposure. However, apples are always on the Environmental Working Group’s “Dirty Dozen” list. This year, apples rank eighth on the Environmental Working Group's 2026 Shopper's Guide to Pesticides in Produce list of conventional produce with the highest levels of detected pesticides.

None of this means you should panic-toss your fruit bowl. In general, both regulatory agencies and food scientists agree that the benefits of eating fruits and vegetables far outweigh the risks of exposure to residues at normal dietary levels. But if you’re after a real upgrade over a ten-second rinse, the fix is sitting in your pantry.

The 15-minute fix
Next time you’re prepping apples, skip the quick splash. Mix about a teaspoon of baking soda with two cups of water. Dip the apples in the solution and let them soak for about 12 to 15 minutes. Rinse and dry. It won't reach pesticide that's already lodged under the skin, but for everything on the surface, it's the closest thing to a proven upgrade over the ten-second rinse most of us grew up with.