Not everyone has a garden, so carefully select produce at the grocery store for preserving, watch out for wax. Most grocery stores sell apples, beets, cucumbers, peppers, squash, tomatoes, turnips, and watermelons that are coated with wax. This makes them look glossier and helps prevent moisture loss.
The wax alone is not so bad. It’s usually made of natural products like beeswax. But the wax is often combined with fungicides to prevent mold problems during shipping and marketing. Since the wax is not water-soluble, it seals the fungicides onto the fruit, making them close to impossible to wash off.
To avoid buying waxed produce, shop at farmers markets, roadside stands, and organic farms or co-ops. Or ask your local grocery store to supply unwaxed produce; you’ll have to take their word for it because it can be hard to see thin layers of wax. If you do buy waxed fruits or vegetables, peel off the outer skin before eating or processing.