How To Wash Lemons To Remove Dirt and Pesticides, According to a Food Scientist

While back at home for the holidays, I noticed a family member zesting a lemon without washing it first. Now, as someone who rinses every fruit and vegetable before eating, zesting, or cutting, I was surprised. Which led me to wonder: How many people use store-bought lemons without washing them first and is this step necessary at all? That’s when I realized, I’m actually not sure why I give lemons a rinse before using them. 

To get to the bottom of these questions, I reached out to Bryan Quoc Le, food scientist and author of 150 Food Science Questions Answered to get his take on washing lemons. 

Is It Necessary To Wash Lemons Before Use?

Necessary? No. Preferred? Yes. “It’s best to wash lemons to remove any dirt residue on the rind,” says Le. “This is especially true if you are zesting the lemon.” If you’re just cutting it to squeeze, washing is not necessary per se, “but some of the dirt from the rind can enter into the lemon when it is cut, so it's good practice to do so. Lemon rinds can have dirt and residues that contain bacteria and potentially food-borne pathogens.”

Le suggests rinsing store-bought lemons and homegrown alike, adding: “It’s good practice to wash lemons picked from the backyard, which could be contaminated with dirt or fecal matter from birds.”

For the most part, any particles that would wash away when rinsing your lemons are going to be physical dirt and, not, for example, pesticides. “Unfortunately, washing a lemon will not remove the pesticide residues, as many of them are fat soluble and will penetrate into the rind on their own accord,” says Le. “They cannot be easily washed off with water as many are not soluble in water.”

The Best Way To Wash a Lemon, According to a Food Scientist 

When it comes to cleaning your citrus, Le says “lemons can be simply washed under cold water for about 30 seconds to dislodge most of the dirt.” Using dish soap is a no-no as “some of the soap residues will dissolve into the rind and can be lodged into the peel.” Furthermore, you should never wash lemons with detergent or bleach solutions as those can also be absorbed into the rind and should not be ingested. It’s also a good idea to steer clear of hot water when rinsing lemons as the heat can begin to break down the vitamin composition and structural integrity of the rind. 

After washing, lemons should be dried with either a dish towel or paper towel and, if you’re not going to use it immediately, Le suggests leaving the citrus out on the counter to continue air drying. “No special precautions are needed when it comes to drying lemons,” says Le, “but they should not be stored wet as this can contribute to the growth of mold.