Here's something that happened to me recently—perhaps you can relate. I was eating a salad with a colleague when I took a bite out of a cucumber. The taste was so bitter and so, well, vile, that I immediately spit it out into my napkin.
A food has to taste pretty terrible for a reasonably polite adult to spit their food out like a four-year-old who's been made to taste a piece of chicken flavored with visible specks of parsley. (Parsley: the enemy of four-year-olds everywhere.) But my actions are justified by science.
Cucumbers—and other members of the pumpkin and gourd family—produce a compound called cucurbitacins that can impart a bitter taste. The amount of cucurbitacins a cucumber contains is increased when the plant faces adverse growing conditions, like a lack of water or excessive heat. (Basically, stress makes cucumbers bitter. Which is not all that different than what happens with people.)
The development of cucurbitacins is an adaptive trait, explains Jonathan Deutsch, a professor of culinary arts and food science at Drexel University. "Bitterness is a good defense against animals that might eat them—including humans," he says. “I can see evidence of this in my own backyard garden—I see two squirrel-eaten green tomatoes on the ground and some bug holes through my sweet basil leaves, but the cucumbers, and, not coincidentally, hot peppers, are looking great!”
Fortunately, the predator-foiling cucurbitacins tend to gather in the peel and ends of a cucumber, and therefore should be easy to avoid: just don't eat the peel and ends.
However, there's one more key step—something I learned years ago from an episode of "Two Hot Tamales"—to avoiding that bitter cucumber taste: Always cut the ends off of cucumbers before you peel them. Fail to do this, and each time you scrape the peeler down the cucumber's length you'll spread bitter cucurbitacins to the rest of the vegetable.
But if you take two seconds to slice those terrible-tasting ends off before peeling (about a 1/2-inch off each end) you'll keep the bitterness contained, thereby keeping your cuke slices fresh and sweet, and—most importantly—avoiding a potentially embarrassing social faux pas.
