The actual cause of bitterness in cucumbers (which also occurs in other gourds, like zucchini,) is due to the compound cucurbitacin. It’s always present in cucumbers, but the levels change based on the vegetables’ growing process. The higher the level of cucurbitacin, the more bitter the cucumber will be. Unfortunately, you can’t tell if a cucumber is becoming bitter while it is still growing and you have time to do something about it. Usually, the bitterness is caused by some climate or soil condition that could be easily solved. Thus, it’s important to take preemptive steps to keep them from becoming bitter in the first place.
What Makes Cucumbers Bitter?
Cultivated cucumbers all contain cucurbitacin B and cucurbitacin C, compounds that are supposed to make their leaves bitter and less tasty to munching animals. These compounds are usually confined to the leaves and stems of the plants, parts of the plant humans don’t eat, so we are not aware they are there. It is only when they move into the fruits that we start detecting a bitter taste. Usually, it is not the whole fruit that turns bitter. More commonly, the bitterness will be concentrated at the stem end and the area right under the skin.
Preventing Bitter Cucumbers
There is still some disagreement about what causes the bitterness to spread into the fruits, but it seems to point to types of stress while the cucumbers are growing. So although we cannot correct the problem after the fact, we can try and avoid the following 3 growing conditions that are potential culprits of bitter cucumbers. So even though cucumber plants grow rather easily, and you can get a prodigious harvest from a couple of plants, to get quality as well as quantity, you need to provide them with good growing conditions: plenty of sunshine, regular water, and rich soil. Finally, look for varieties that are well-suited to your area and that are labeled “non-bitter”. Some reliable varieties are ‘Marketmore 97’, ‘Diva’, ‘Eversweet’ (any variety with “sweet” in the name), ‘Long Green Improved’, and the heirloom ‘Lemon’. As with all plants, edible or otherwise, the real trick to healthy, productive cucumber plants is to research what growing conditions the plant prefers and do your best to provide them. Even a few days of stress can cause a ripple effect of damage. Ornamental plants will probably recover, but you only get one chance to get it right with cucumbers and other edible plants. That’s why it is so important to put some thought into choosing both your growing site and your edible varieties.
What to Do with Bitter Cucumbers
If you find yourself with bitter cucumbers, don’t automatically reach for the compost bucket. Peeling the fruit should improve the flavor. Cut off the first inch or two from the stem end and test the flavor. If it’s still bitter, try a slice toward the center of the cucumber and see if it is sweeter. You should be able to salvage more than enough for a salad. And as soon as you notice a bitter cucumber, take the precautions above to ensure the rest of your harvest doesn’t suffer the same fate.
