Why Does Cilantro Taste Like Soap?

Fresh or dried cilantro adds a tangy citrus flavor to recipes, but some people think it tastes like soap.
Fresh or dried cilantro adds a tangy citrus flavor to recipes, but some people think it tastes like soap. Siriporn Kingkaew / EyeEm / Getty Images

Cilantro is a green, leafy herb that resembles parsley. It's the leafy part of the coriander plant (Coriandrum sativum), which produces seeds that are used as a spice. For those who appreciate it, cilantro tastes like a stronger version of parsley, with a tangy citrus flavor. However, some people loathe cilantro. Between 4% and 14% of tasters describe the flavor of cilantro as soapy or rotten.

Why is such an innocent-looking plant so reviled? The soap taste is real for some people and there is a scientific reason behind it. It's all about genetics.

Key Takeaways

  • Cilantro is the leafy part of the coriander plant. The plant is related to parsley and looks similar, but has a stronger flavor with an added citrus tanginess.
  • 4-14% of tasters describe cilantro as soapy or rotten in taste. The percentage varies depending on ethnicity and is lower in regions featuring cilantro in cuisine.
  • Genetic differences affect the perceived flavor of cilantro. Gene OR6A2 is an olfactory receptor gene that codes for a receptor sensitive to aldehydes, which are the compounds largely responsible for the aroma and flavor of cilantro.
  • Sensitivity to aldehydes causes the soapy scent and flavor to overpower any pleasant herbal notes.

Flavor Perception Relates to Ethnicity

Studies on the perceived flavor of cilantro have found that between 4% and 14% of tasters think the leaves taste like soap or taste rotten. Dislike for cilantro varies among ethnic groups, with 12% of East Asians, 17% of Caucasians, and 14% of person of African descent expressing aversion to the herb.

However, if cilantro is a popular component of local cuisine, fewer people dislike it. Where cilantro is popular, 7% of South Asians, 4% of Hispanics, and 3% of Middle Eastern respondents identified a dislike of the flavor. One explanation is that familiarity with the flavor, whether it tastes soapy or not, increases the odds of liking it. Another explanation is that people within an ethnic group share more common genes.

Cilantro is the leafy part of the coriander plant. The seeds are coriander spice.
Cilantro is the leafy part of the coriander plant. The seeds are coriander spice. kolesnikovserg / Getty Images

Genetics and Cilantro Flavor

The link between genetics and cilantro flavor was first identified when researchers found 80% of identical twins share a like or dislike of the herb. Further investigation led to identification of the gene OR6A2, an olfactory receptor gene that makes a person sensitive to aldehydes, the organic compounds responsible for cilantro flavor. People who express the gene find the smell of unsaturated aldehydes offensive. Additionally, they can't smell the pleasant aromatic compounds.

Other genes also affect the senses of smell and taste. For example, having a gene that codes for increased perception of bitterness also contributes to a dislike for cilantro.

Other Plants With a Soapy Flavor

Linalool is a molecule with a distinctive fragrance and soapy flavor.
Linalool is a molecule with a distinctive fragrance and soapy flavor. ollaweila / Getty Images

A variety of unsaturated aldehydes contribute to cilantro's aroma and flavor. However, the terpene alcohol linalool is the one most associated with the herb. Linalool occurs as two enantiomers or optical isomers. Basically, the two forms of the compound are mirror images of each other. The one found in cilantro is (S)-(+)-linalool, which has the common name coriandrol. The other isomer is (R)-(-)-linalool, which is also known as licareol. So, if you're sensitive to the soapy flavor of coriander, other plants may also smell and presumably taste like a shower stall.

Coriandrol occurs in lemongrass (Cymbopogon martini) and sweet orange (Citrus sinensis). Licareol is found in bay laurel (Laurus nobilis), sweet basil (Ocimum basilicum), and lavender (Lavandula officinalis). The soapy flavor of lavender is so pronounced that even people who like cilantro often object to lavender-flavored food and drinks. Hops (Humulus lupulus), oregano, marjoram, and marijuana (Cannabis sativa and Cannabis indica) are similarly high in linalool and taste like dishwater to some people.

A person who dislikes cilantro would also find lavender lemonade soapy-tasting.
A person who dislikes cilantro would also find lavender lemonade soapy-tasting. Westend61 / Getty Images

Sources

  • Knaapila, A.; Hwang, L.D.; Lysenko, A.; Duke, F.F.; Fesi, B.; Khoshnevisan, A.; James, R.S.; Wysocki, C.J.; Rhyu, M.; Tordoff, M.G.; Bachmanov, A.A.; Mura, E.; Nagai, H.; Reed, D.R. (2012). "Genetic analysis of chemosensory traits in human twins". Chemical Senses. 37 (9): 869–81. doi:10.1093/chemse/bjs07
  • Mauer, Lilli; El-Sohemy, Ahmed (2012). "Prevalence of cilantro (Coriandrum sativum) disliking among different ethnocultural groups". Flavour. 1 (8): 8. doi:10.1186/2044-7248-1-8
  • McGee, Harold (April 13, 2010). "Cilantro Haters, It's Not Your Fault". The New York Times. 
  • Umezu, Toyoshi; Nagano, Kimiyo; Ito, Hiroyasu; Kosakai, Kiyomi; Sakaniwa, Misao; Morita, Masatoshi (2006). "Anticonflict effects of lavender oil and identification of its active constituents". Pharmacology Biochemistry and Behavior. 85: 713–721. doi:10.1016/j.pbb.2006.10.026
  • Zheljazkov, V. D; Astatkie, T; Schlegel, V (2014). "Hydrodistillation extraction time effect on essential oil yield, composition, and bioactivity of coriander oil". Journal of Oleo Science. 63 (9): 857–65. doi:10.5650/jos.ess14014