Here's the Best Way to Wash Apples, According to Science

When preparing produce, the Food & Drug Administration recommends that you wash fruits and vegetables thoroughly under running water beforehand to, at the very least, remove any dirt and bacteria. But what if you're worried about any excess pesticides that may remain? A study published in the Journal of Agricultural and Food Chemistry set out to specifically answer this question: What is the best washing method for removing pesticides from apples?

Researchers from the University of Massachusetts looked at the effectiveness of three washing methods when it comes to removing two types of pesticides – thiabendazole, a fungicide, and phosmet, an insecticide. In preparation for the experiment, apples were exposed to both of these pesticides for 24 hours. The fruit then went through one of three cleaning methods: tap water, as the FDA recommends, a Clorox bleach solution often used in the apple industry postharvest, and a solution of water and baking soda (sodium bicarbonate) that most people could make at home.

Of the three methods, the study concluded that a baking soda bath was the most effective for extensive removal of both pesticides. The solution was able to completely remove all thiabendazole and phosmet residue from the surface of the apple when the fruit was soaked for 12 and 15 minutes respectively and then rinsed with water.

Although the baking soda method was extremely successful at removing surface residues, however, the researchers warned that pesticide residues that had seeped into the skin – called "internalized pesticides" – still lingered. As a result, the study suggests that peeling is a more effective way to remove the penetrated pesticides, but this means that you will lose the benefit of the vitamins and minerals that are in the peel.

Beyond simply advising those at home on the best way to wash off pesticides, the authors also had a takeaway for the apple industry. "This study gives us the information that the standard postharvest washing method using Clorox bleach solution for 2 min is not an effective means to completely remove pesticide residues on the surface of apples," the paper states. How do you like them apples?