Why does my mouth taste like soap?

There are few things worse than getting soap in your mouth. It doesn't happen often but it's bound to have gotten in there at some point in your life, and it takes a while to shake it off. But what if your mouth taste like soap, but you haven't been anywhere near a bar of soap? It can be as disconcerting as when your mouth tastes like metal, but it has different potential causes. 

According to Healthline, the most common reason that your mouth tastes like soap is because you've eaten a certain type of food such as carrot and coriander (also known as cilantro), which actually comes down to your genetics. As Professor Russell Keast, who specializes in sensory and food science at Deakin University's School of Exercise and Nutrition Sciences, explains, "We have smell receptors in our nose that are responsible for identifying volatile compounds in the atmosphere, including volatile compounds released from potential foods." 

These receptors differ from person to person, and aid in deciding how things like coriander and carrot taste and smell. For some, this means carrots and coriander will taste like soap from the day they are born, and no matter how good it looks, it will still taste awful.

Fluoride can cause a soapy flavor in your mouth

It's important to know taste doesn't come down to smell receptors alone. It may also differ from one person to the other simply because of the culture or house they grew up in. "For example, many Australians have problems with the intensity of fish sauce, yet South-East Asian populations find it an integral part of their flavoring," said Keast. However, while you can sometimes force yourself to like the taste of certain food, Keats says your genetic smell receptors will never change.

If you constantly have a soapy taste in your mouth, Healthline notes that overexposure to sodium fluoride could be the reason. While it is often found in toothpaste and water, when you consume or are exposed to too much of the chemical, you're likely to experience a soapy taste in your mouth, along with other symptoms such as diarrhea, vomiting, and abdominal pain, among others. In this case, you should seek help from a medical professionally immediately as you may actually have fluoride poisoning.