Pesticide is a common concern when you eat produce that isn't grown organically. While washing the fruit may work on large pieces, grapes present a challenge because of their many small pieces and crevices. To remove pesticide from grapes, begin by washing them in water, then submerge them in a vinegar-and-water mixture.

1、Remove the grapes from their stems, place them in a colander, and rinse them in running water for 30 seconds or more. Bounce and shake the grapes around in the colander to ensure water reaches each one.
2、While rinsing the grapes in running water, rub them gently with your hands to further remove pesticide. A 1997 study by the Connecticut Agricultural Experiment Station showed that rubbing the fruit helps remove more pesticide.
3、Remove any stems or debris that have come off the grapes, and place the grapes into a pot or bowl.
4、Add 1 teaspoon of vinegar for every liter of water in the pot or bowl. Leave the grapes in the mixture for 10 minutes.
5、Drain and rinse the grapes.

From Network Resources