The 1 Reason Cucumbers Are Waxy

It’s officially cucumber season, and I’m going to enjoy this crunchy and refreshing vegetable in as many ways as possible—chopped in salads, sliced in sandwiches, and pickled as a gift to my future self.

I mostly get cucumbers from my local grocery store, and the other day, it struck me that the ones I buy have a waxy coating. Why is the skin covered with wax? Is the wax safe to eat? To find out, I asked two food scientists to weigh in. 

Why Do Cucumbers Have a Waxy Coating?

While cucumbers naturally have a waxy protective layer, they get washed off during processing after they are picked from the plant. It’s common for processors to add a layer of wax to cucumbers before they are sent off to grocery stores for sale. The added wax mimics the wax naturally produced by the cucumbers.

According to the U.S. Department of Agriculture’s Agricultural Marketing Service, the wax prevents the cucumbers from shriveling and improves their appearance. It protects the cucumbers during processing, transportation, and storage.

“Cucumbers have an edible wax added to the skin to prevent moisture loss and slow down oxidation,” adds Brian Chau, food scientist and principal of Chau Time, a San Francisco-based food consultation firm focused on research and development.

“Field-grown cucumbers experience moisture loss due to temperature variances at harvest and then moving through storage and transportation,” adds Lara Tiro, food scientist and consultant of Rebel Botanica Inc., a Vancouver-based food product development consulting company. 

Are All Cucumbers Waxed?

Chau says that most processors add wax on cucumbers if sold in bulk to retailers as whole cucumbers. In this case, the FDA requires the processor to disclose that wax was applied to the cucumbers.

Once the vegetable is in the retailer’s hands, they must inform customers that a wax coating was applied, either on a label placed on the cucumber or on signage next to the product.

Not all varieties of cucumbers have the wax coating added. “Greenhouse-grown cucumbers, typically known as seedless cucumbers, a thin-skinned variety, are not waxed. Instead, they are individually shrink-wrapped in polyethylene film,” says Tiro.

Mini greenhouse cucumbers are also unwaxed and packaged in resealable polyethylene bags or film trays with holes. The packaging acts as the protective layer. Most cucumbers that are not packaged or shrink-wrapped have a wax coating.

Is the Wax Coating Safe To Eat?

A U.S. Food & Drug Administration (FDA)-approved food-grade wax, such as carnauba wax, is sprayed on or used to dip the cucumbers after harvesting. The FDA regulates wax coating used on fruits and vegetables, ensuring they are edible and safe. Both conventional and organic wax coatings are available for producers to use.

In recent years, a new technology developed by California-based company Apeel Sciences is getting the attention of the food science and agricultural communities. Its product, Edipeel, is a thin coating made from plant-based materials that are Generally Recognized as Safe (GRAS) by the FDA. Tiro says using Edipeel has shown promising results for cucumbers to move away from polyethylene film.

You Can Remove the Wax Coating

If you prefer not to eat the wax, Chau suggests rinsing and brushing the cucumber to remove the wax. “This is a labor-intensive process and can take 10 to 30 minutes,” Chau adds. Peeling the skin off may be the best option.

Chau adds that you may find unwaxed organic cucumbers at your local farmers markets or Community Supported Agriculture.

Can You Use Waxed Cucumbers To Make Pickles?

While you can use waxed cucumbers to make pickles, Chau doesn’t recommend it, as the brine will have a tougher time penetrating the cucumbers. He adds, “You can increase the brine penetration by cutting the cucumbers before placing them in the brine, but using unwaxed cucumbers is the easiest.”

Tiro agrees, “Pickling cucumbers are best for pickling as they are not waxed.”