Are Burpless Cucumbers Really Burpless?

I never thought cucumbers were so complicated. When ordering seeds you can certainly order burpless cucumber seed. And the English cucumbers are burpless, or at least my wife thinks since she always complains when I buy the American slicing variety at the grocery store.

I recently posted about a popular procedure for making cucumbers less bitter, on our popular Garden Fundamentals Facebook Group, and someone asked, are the bitter free cucumbers really burpless?

Good question. I thought the answer was yes, and so do 99% of the blog posts on line that talk about this topic. Guess what? We are wrong. Lets stop burping and sort it all out.

What is a Burpless Cucumber?

So called burpless cucumbers are marketed in the US by numerous seed companies.

I’ll quote from Burpee Seed Company, a major supplier of seeds to gardeners in the US, “Burpless’ cucumbers, both American and Asian types, contain low or no cucurbitacin, the compound that causes bitterness and increases one’s susceptibility to ‘burping’ after eating the fruits.”

This is a common belief among seed companies, bloggers and gardeners.

The term American type refers to a fuller fruit, which has a thicker skin. It is also called the slicing cucumber or field cucumber. The original version of this cucumber did have a bitter taste but newer cultivars have the bitterness bred out of them.

The Asian type is a more slender fruit, that is longer, and is usually sold wrapped in plastic to keep it from drying out. It also goes under the name of English cucumber, telegraph cucumber and trellis cucumber.

This latter type of cucumber is known for being sweeter, having less bitterness and being burpless.

What Causes Bitterness?

I have reviewed this in detail in How to Grow Cucumbers Without Bitterness. In summary, a compound called cucurbitacin makes the fruit bitter.

Are Burpless Cucumbers Real?

What Are Burpless Cucumbers, is the title of a research project carried out by Todd C Wehner, an expert on breeding cucumbers and a professor of horticultural science at North Carolina State University. He tested three different cultivars to see if they cause burping. There were six test subjects, half of which had burping problems after eating cucumbers, and the remaining three had no problem. They received samples every two weeks over two seasons and were asked to eat them, and provide a numeric value as to the degree of burping they caused.

Subjects who’s digestion is not affected by cucumbers could not distinguish between American bitter (Marketmore 76), American non-bitter (Marketmore 80) and English (Tasty Bright). None caused burping for them.

Subjects who did have a burping problem found that American bitter and American non-bitter both caused significant burping and to the same degree. The English cucumber caused minor burping.

This test only looked at one cultivar of each type of cucumber. It’s not clear if any of the other American style cucumbers are burpless, but seeds from some sources are certainly promoted as such, but this may be due to the incorrect assumption that bitterness and burping are both caused by cucurbitacins.

Are English Cucumbers Bitter Free?

You probably think the answer here is obvious. If you have eaten them then you know they are bitter free.

To test if they produce cucurbitacins, the bitter compounds in cucumbers, subjects were asked to eat cotyledon leaves. These judges were specially trained to evaluate bitterness and this is a common technique used to evaluate breeding efforts.

All 12 of the tested English cucumbers were bitter.

In hindsight, this is not surprising since none of these English cultivars have been bred to remove the genes that cause bitterness.

English cucumbers possess the genes for making them bitter, the vegetation is bitter, but not enough of the chemical enters the fruit to make it taste bitter to us. From a chemical and genetic perspective, they are NOT bitter free.

What Causes Burping After Eating Cucumbers?

Many believe that cucurbitacins also cause burping and some believe it is the seeds.

Since English cucumbers produce cucurbitacin and are burp free, these compounds are not the cause of burping, as so many sources claim.

The reality is that research has not identified the compounds that cause burping. I can’t even find out what percent of the population has this problem.

The Truth About Cucumbers

To sum things up:

• American cucumbers are probably not burp free, but some cultivars are bitter free.
• English cucumbers may not taste bitter, but they do carry the genes for bitterness and they do produce cucurbitacins. They are not burpless but they do cause less burping than American types.
• In cucumbers, bitter free does not mean burpless.
• Nobody knows why some people burp after eating cucumbers.

More Cucumber Posts:

Should Cucumbers, Squash, Muskmelons and Watermelons be Grown Near Each Other?

How to Grow Cucumbers Without Bitterness