There's a Scientific Reason Why Some People Think Cilantro Tastes Like Soap
Passionate dislike for cilantro is real. A website called IHateCilantro collects vitriolic haikus about this "awful herb." Common descriptors from cilantro-haters include "detergent," "soap," and "kerosene." In recent years, scientists have tried to figure out where the intense loathing comes from—and whether it's learned or genetic.
Cilantro is an herb in the carrot family, one of the most varied and wondrous plant families for human consumption. Some of cilantro's cousins include celery, parsley, cumin, fennel, and dill.
Herbs like cilantro are extremely powerful in flavor, which is why they're classified as herbs rather than edible leaves. The difference between, say, basil and spinach, culinarily speaking, is raw strength: you wouldn't really want to eat large quantities of an herb. Because herbs are so strong, it's not necessarily surprising that some people would have an aversion to herbs, but the particular venom aimed at cilantro is definitely unusual. You don't hear people claiming that marjoram makes them angry, you know?
Cilantro is native throughout southern Europe, southwestern Asia, and northern Africa, and has become massively important in those cuisines and those they influenced. It's most commonly found in the food of Latin America, Southeast Asia, and the Middle East.
Manifestations of the distaste for cilantro are a bit of a jumble. A dominant perceived flavor is "soapy," but that's all mixed up with general dislike. Scientists have lately been trying to figure out exactly what's going on with cilantro hatred, and have some—but not all—answers.
Researchers at DNA-testing outfit 23andMe performed a survey, asking people whether they thought cilantro tastes like soap, and compared those answers with the DNA results they already had. They found a common genetic variant among the cilantro-haters: an olfactory-receptor gene cluster called OR6A2. Basically, some people have some sensors in their smell/taste genes that make them especially sensitive to aldehyde chemicals—and cilantro is very strong in those, as is the soapmaking process.
Other studies have narrowed in on completely different sensors in cilantro-haters. Some have focused on geographic distribution. A study funded by The Advanced Food and Materials Network, a Canadian academic organization devoted to food science and technology, for example, finds that Caucasians are much more likely than South Asians to strongly dislike cilantro. But the 23AndMe study also tested whether cilantro-hate is passed down through generations and found that it wasn't, saying the heritability is very low. So if heritability is low, and this mutation is sort of random, why do people in regions with cilantro-heavy cuisines show less cilantro hatred?
This isn't an incredibly well-studied research topic, but it looks as though there is a genetic basis for cilantro dislike. That said, that genetic basis may simply be one factor, and not even necessarily a major one, in cilantro-hatred. Where you grow up, and what kind of food you eat, might be just as important. And, as food scientist Harold McGee notes, learning to love cilantro is certainly possible.
If you just can't overcome your dislike of cilantro or are cooking for someone who is cilantro-adverse, our Test Kitchen suggests swapping in Italian parsley for cilantro in your cooking so everyone can enjoy their meal.