Cilantro, known as phak chee in Thai, brightens tom yum, elevates larb, and finishes many street-side soups. A small but vocal segment of diners finds its flavor soapy. New research shows this aversion is genetic, not simply a personal preference, offering a fresh lens on how Thais experience food.
In Thai cuisine, cilantro’s citrusy zing is celebrated for lifting dishes from sour to savory. Yet the soapy bitterness has puzzled cooks and diners for years. Research indicates that genetic differences influence how cilantro tastes to different people.
The science centers on aldehydes, natural compounds in cilantro responsible for its distinctive tang. For most people, aldehydes contribute a fresh note. But roughly 3 to 21 percent of individuals—varying by ethnicity—perceive a soapy, bitter aftertaste. This variation is linked to a gene called OR6A2, which encodes an olfactory receptor highly sensitive to cilantro’s aldehydes. People with a particular OR6A2 variant are more likely to describe cilantro as soapy and bitter.
A landmark study from 2012 established the link between soapy cilantro perception and a nearby genetic variant. The gene is part of a family of receptors that help interpret aromas, underscoring the close tie between smell and taste that explains why cilantro tastes so differently across people.
Beyond flavor, cilantro offers nutritional value. It provides vitamin C, vitamin K, and folate, along with minerals such as potassium, calcium, and magnesium, supporting heart health and electrolyte balance. This profile reinforces cilantro’s role in health-conscious Thai homes and eateries.
Genetic aversion is not uniform across populations. Detection studies show higher dislike among Northern Europeans, while Southeast Asians and Latinos show broader acceptance. In Thailand, anecdotal evidence suggests dislike is relatively rare; when present, the soapy sensation can dominate other flavors, prompting menu adaptations and family debates.
Thai diners who dislike cilantro report a range of experiences—from mild discomfort to strong aversion. In kitchens and markets, many adjust by omitting cilantro or substituting with parsley or green onion. Some diners report gradual acclimation through exposure or by masking cilantro with bolder ingredients, or using dried leaves instead of fresh to temper the aldehydes.
Medical professionals note that while some palate adaptation is possible, the genetic sensitivity often persists. The OR6A2 receptor keeps those affected highly aware of the offending aldehydes, making cilantro a lifelong sensory difference for some. Thai chefs acknowledge this reality and respond with flexible menus and optional cilantro garnishes to respect diverse palates.
This genetic understanding helps explain regional variations in Thai cuisine. It also informs how restaurants cater to international visitors whose home cuisines may be less tolerant of cilantro’s soapy note. As Thai chefs expand internationally, offering cilantro as an option rather than an obligation supports inclusive dining.
Looking ahead, genetic insights could influence recipe design in homes and restaurants. Thai cooks and hospitality operators may increasingly tailor dishes to suit a broader range of palates, especially in fusion concepts and overseas outlets. The trend emphasizes inclusive menus that honor taste diversity without compromising authenticity.
What should Thai consumers and restaurateurs do? Respect genetic differences by presenting cilantro as an optional ingredient. Menu labeling that highlights cilantro as a garnish or permitting customers to request its removal supports personalized dining experiences. Families can introduce cilantro gradually but should understand that for some, the soapy taste is a fixed trait, not a phase.
For those curious whether they carry the cilantro gene, start with a small leaf and note any aftertaste. If so, consider masking cilantro with stronger flavors or using dried forms, which contain lower levels of the offending compounds. Substitutes such as culantro or basil are widely available in Thai markets and can maintain the dish’s brightness without triggering the same reaction.
Taste is deeply personal and often biologically embedded. Understanding why cilantro tastes like soap for some can foster empathy and inclusive dining at Thai tables and in restaurants. The takeaway: embrace adaptability, respect genetic diversity, and ensure everyone can enjoy Thai cuisine to the fullest—cilantro included or left aside.
Data from genetic research on cilantro helps explain the aroma perception across populations and its implications for culinary practice and nutrition education in Thailand.