Answer: Cilantro

If you like food seasoned with the herb cilantro (coriander), you probably like the crisp citrus notes it adds to your food or maybe you have no opinion on the matter and are indifferent to the flavor of the commonly used herb. If you don’t like cilantro, however, you’ve probably got a very passionate dislike of it and with good reason.

There is an olfactory receptor gene known as OR6A2, and if you have this gene, you are more sensitive to the smell of aldehyde chemicals (which are found in various forms in many fragrant things like cinnamon and vanilla). The aldehydes found in cilantro, however, happen to be very similar to the aldehydes found in soap, and there is an overlap between cilantro’s aldehydes and those excreted by stink bugs. Delicious.

For people with the genetic propensity to smell these particular aldehydes better than others, that means eating cilantro tastes, courtesy of the strong cooperation between our sense of taste and sense of smell, like chewing on flakes of soap (or flakes of stink bugs if you really want a delightful mental image). It’s no wonder then that some people have a pretty serious aversion to food with cilantro in it.