Distilling tastes and flavors to their most basic constituents is essential to making food the tastiest it can be. We currently know of five basic tastes: sweet, sour, salty, bitter and the somewhat hard to pin down umami (think savory or anchovies, tomato juice, the likes). Now, a group claims it has pinned down the sixth: fat. Bacon lovers throughout the world might rejoice at the news. However, if you like bacon you should feel grateful you didn’t take part in this study because isolated fat molecules are reportedly awful tasting. Distinct yes, but quite awful. In fact, to distinguish from what people generally refer to as “fat”, the researchers at Purdue University propose a new term to describe the sixth basic taste: oleogustus.

The inside of the mouth is littered with taste buds, each with 100 or so receptors that chemically bind with the food and send a signal to the brain. This signal is what we eventually perceive as a taste or flavor. The most taste buds are found on the tongue, but you’ll find other buds on the throat, top, bottom and side of the mouth. The average person has around 10,000 taste buds in their mouth and throat. The peak is hit in childhood then these progressively wither as you age. The older you get, the less better you’ll be at discerning the various tastes and flavors found in the food you ingest.

Though there are a myriad of flavors and tastes, these can be broken down to a couple of basic tastes. Similarly to how the primary colors (yellow, blue, red) can be combined to rend other colours, so can basic tastes combine in various degrees to form new flavors. Taste is a bit more complicated than sight though, and a lot more subjective. “There is no accepted definition of a basic taste,” said Michael Tordoff, a behavioral geneticist at the Monell Chemical Senses Center in Philadelphia. “The rules are changing as we speak.”

So, the jury is definitely not done with what constitute the basic tastes, but scientists are working it out. For good reasons, too. Understanding vision and how colours work is essential to the latest display technology like smartphones or LED TVs we all know and love. Similarly, the food industry can use molecular interactions to make food tastier or come up with new flavors altogether. Pinning down what the basic tastes becomes quite important in this context. So far, there are six such basic tastes, the latest one being oleogustus.

To confirm fat as the sixth basic taste, Richard Mattes, a professor of nutrition science at Purdue University, offered more than 100 participants isolated solutions which contained one of the six tastes: sweet, sour, salty, bitter, umami and fat (nonesterified fatty acids). The participants were asked to group each solution they sampled in a group. They had no problem grouping three basic tastes:  sweet, sour and salty. The rest were a bit ambiguous to the participants. So, most grouped the rest of the samples into one large group that served as a stockpile for all that is weird, gross and essentially awful (even bitter and umami taste terrible when isolated).

Elucidating further, the researchers made a new experiment with another group of participants. This time, only three isolated tastes were offered. This time, the participants easily divided the solutions into three distinct tastes, as expected. While there was some overlap with the solutions for sour and umami tastes, the majority of people were able to identify oleogustus as a taste distinct in itself, as reported in Chemical Senses.  

“There isn’t a firm agreement about what characteristics are necessary, but we have a pretty solid sense,” said Mattes. “We just needed to prove that it produced a sensation that was unique from the other primary tastes.”

“Understanding this could have huge implications for the food industry,” said Mattes. “It could make a lot of food taste a lot better.”

What about the seventh or eighth basic taste? Well, there may be other candidates as well. These include metallic (self explanatory), piquance (the burn you feel on your tongue from peppers), coolness (minty and fresh sensation from peppermint or menthol) or carbon dioxide (the zingy fizz you get from soda, beer, champagne and other carbonated beverages).