Why Some Cucumbers Are Bitter—and What You Can Do About It

We love a cucumber's fresh, mellow taste, but they can sometimes be noticeably bitter. What gives? Is it a result of improper cucumber storage or how the cucumber was grown? And, perhaps most important, is there anything that can be done about it? Here, experts explain what makes cucumber bitter, plus how to prevent this problem in homegrown cucumbers and tips for using up the bitter ones.

What Makes Cucumbers Bitter?

A specific compound called cucurbitacin is responsible for the bitter flavor. "Cucurbitacin is generally more concentrated in the skin and towards the stem end of the fruit," says Tucker Taylor, director of culinary gardens at Kendall-Jackson Wine Estate & Gardens in Sonoma County. "Lack of proper irrigation is the main reason cucumbers can be bitter, but cold weather can also be a culprit."

Taylor adds that while some cucumber varieties are grown for their more bitter flavor, most modern varieties that you'll find at your local supermarket or farmers' market lack bitterness when grown properly.

How Can You Tell If a Cucumber Will Be Bitter?

Unfortunately, there's no definitive way to tell that a cucumber is bitter just by looking at it. Taylor notes that misshapen cucumbers tend to be more bitter than normally shaped ones, and seedless cucumbers with thin skins tend to be less bitter, but the only way to know for sure is to taste them.

"It's tough to tell if a cucumber is going to be bitter by its appearance," says John Amann, co-chef of Castle Hot Springs in Morristown, Arizona. "Sometimes it's hit or miss in the summertime, which beds in the farm will have a volunteer bitter cucumber."

Ways to Make Cucumbers Less Bitter

Since cucurbitacin tends to be concentrated in the stem end and just under the skin, Ian Beger, resident agronomist of Castle Hot Springs, recommends cutting off the stem end and peeling the cucumber as an easy way to eliminate most of the bitterness.

How to Prevent Bitter Cucumbers in the Garden

The best way to avoid bitter cucumbers is to grow bitter-free varieties, such as Sweet Slice and Sweet Success. Additionally, since poor watering can increase bitterness, it's a good idea to water cucumber plants once a week, especially when the weather is dry and hot.

You should also make sure the soil is rich in organic matter, as soil that is lacking nutrients can cause bitter cucumbers. To do this, incorporate compost or other organic matter into the soil when planting and feed cucumber plants a balanced fertilizer regularly, about every month or two. Make sure to plant cucumbers in a spot where they get enough sun and space plants out so they can absorb all the resources they need without fighting for it.

Can You Use a Bitter Cucumber?

Yes, you can still enjoy a slightly bitter cucumber. Taylor likes to make quick pickles with cucumbers that are on the bitter side. He recommends using seasoned rice wine vinegar, which has salt and sugar to help balance the bitterness.

"You can have delicious pickles in about an hour or so," he says. "Use these to top off your noodle bowls or salads, add in a stir fry, or just by themselves!" However, if the cucumber is just too bitter to eat, Amann recommends composting it.