What's the Best Way to Wash Apples?

How do you wash your apples? Everyone has a favorite technique, from rinsing under a tap to rubbing vigorously with a cloth to soaking in a special cleaning solution. But which one of these is actually most effective at getting rid of pesticide residues? Scientists from the University of Massachusetts, Amherst, decided to answer this question, just in time for this year's apple-eating season.

Led by chemist Lili He, the researchers sprayed organic Gala apples with two pesticides commonly used in the apple industry—thiabendazole, a fungicide, and phosmet, an insecticide. The apples sat for 24 hours, then were washed in one of three different solutions—a plain water solution, a bleach solution, and another water solution containing 1% baking soda.

They found that baking soda was the best way to get rid of pesticides.

From Consumer Reports: "Submerging apples in a baking soda solution for two minutes removed more pesticides than a two-minute soak in the bleach solution, or two minutes of rinsing in running tap water. But it took 12 to 15 minutes in the baking soda solution to completely get rid of the pesticides used in this study."

Some of the pesticides had already entered the fruit, however, which made it impossible to wash off. The researchers wrote in the abstract that "20% of applied thiabendazole and 4.4% of applied phosmet had penetrated into the apples following the 24 h exposure." Thiabendazole penetrated four times deeper than phosmet, "which led to more thiabendazole residues inside the apples, which could not be washed away using the NaHCO3 [baking soda] washing solution."

Bleach's lack of effectiveness shouldn't come as a surprise. After all, the Environmental Protection Agency requires that all apples sold in stores be washed in a bleach solution prior to sale, but this is meant only to get rid of dirt and bacteria; it does nothing for pesticides.

Worth noting is that this study only used two pesticides, whereas the apple industry has many more on its list of acceptable chemicals. Some of these penetrate deeply into the fruit, in which case you will not be able to remove them, no matter how well you wash them.

Peeling is another effective way to reduce pesticide exposure, but then you lose out on the fiber and vitamins in the skin. Buying organic is your best bet for reducing exposure to chemicals, although even organic apples can be sprayed with certain pesticides, usually natural ones, according to the National Pesticide Information Center.

Use the baking soda technique by mixing 1 teaspoon of soda in 2 cups of water and leaving apples to soak for 15 minutes.