The Real Reason Cucumbers Look and Feel 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 I’ve noticed that they always look and feel waxy. Why is the skin covered with wax? Is the wax safe to eat? I recently asked two food scientists to weigh in. 

Why Are Cucumbers Waxy?

While cucumbers naturally have a waxy protective layer, it gets washed off during processing, after they are picked from the plant. So it’s common for processors to add a layer of wax to cucumbers. The added wax mimics the wax naturally produced by the cucumbers.

The wax prevents the cucumbers from shriveling and improves their appearance, according to the U.S, Department of Agriculture's Agricultural Marketing Service. 

"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.

The wax protects the cucumbers during processing, transportation, and storage. "Field-grown cucumbers experience moisture loss due to temperature variances at harvest and then moving through storage and transportation," explains Lara Tiro, food scientist and consultant of Rebel Botanica Inc., a Vancouver-based food product development consulting company. 

Are All Cucumbers Waxed?

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

Once the vegetable is in the hands of the retailer, they have to 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. Most cucumbers that are not packaged or are shrink-wrapped have a wax coating. That’s because the packaging acts as the protective layer.

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. Their product, Edipeel, is a thin coating made from plant-based materials that are GRAS (Generally Recognized as Safe) by the FDA. Tiro says that using Edipeel has shown promising results for greenhouse 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 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 options of organic cucumbers at farmers markets or Community Supported Agriculture near you.

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 says, "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, the shortest of the three cucumber types, is best for pickling as they are not waxed.