Table of Contents
What, exactly, does nothing taste like?
Water—bottled, tap, mineral, or sparkling. It might even have a lemon slice or some mint leaves. Water from the tap and water from the bottle don’t taste the same; but how do we know what exactly water tastes like?
How do we taste things?
If you’ve ever looked at your tongue closely in the mirror, you might have noticed hundreds of tiny little bumps, called taste buds. Each bump is filled with 50–100 taste receptor cells . There are four types of taste receptors, and scientists haven’t quite figured out what each one does. The first type of taste receptor detects changes in salt concentration. The second type is what allows us to taste bitter, sweet, and umami, and are the best-studied taste receptors. The third receptor is sour, and the fourth type’s purpose is still unknown. Scientists think tasting water involves both the “sour” receptor and detecting salt, so the first and third types of taste receptors are what allows humans to detect what water tastes like.
Compounds responsible for sweetness, bitterness, or umami bind to the outside of the cell, triggering a specific nerve impulse . Taste is an important part of human evolution, and scientists think taste is what allowed early humans to detect poisons and other toxic substances. Toxins are usually bitter and activate the bitter taste receptor. Bitterness is unpleasant, making us avoid bitter and therefore potentially toxic substances.
What changes the taste of water?
Tasting water involves both the salty and sour taste receptors. A study done on mice found that activating the “sour” taste receptor induces the mice to feel thirsty—extra thirsty if they were water-deprived before the experiment. This might be an evolutionary adaptation , ensuring that we drink as much water as possible when it is available.
Humans are also quite good at telling waters apart! In a blind taste test, scientists gradually changed concentrations of various minerals. Tasters were most sensitive to sodium, potassium, and chlorine concentrations. Interestingly, a medium concentration of these compounds seemed to be the tastiest. Too high or too low, and the tasters disliked it—kind of like Goldilocks! This too might be an evolutionary adaptation. Pure water with no minerals can actually draw water out of your body, dehydrating you. Too many minerals and the water might not be potable and might contain toxic compounds.
Although we can rank water quality and tell what tastes better or worse, it’s incredibly hard to actually describe the taste of water. This is because water doesn’t bind to a type two receptor, and is more a perception of salt and sourness than taste itself. Next time you drink a glass of water, try to tell if you like it or not. It might be an evolutionary pressure protecting you from toxins and making sure you don’t get dehydrated.
Flesch Kincaid Grade Level: 55.3
Flesch Kincaid Reading Ease: 9.5
Glossary
Adaptation: A bodily feature or behavior that allows an organism to withstand an unfavorable environmental condition
Compound: A chemical substance with a specific shape and size
Taste receptor cell: A group of four types of cells present in the human body, allowing the perception of taste
Nerve Impulse: An electrical signal that encodes information and can be transmitted through the body
Potable: Describes water that is safe to drink
References
https://awwa.onlinelibrary.wiley.com/doi/abs/10.1002/j.1551-8833.2007.tb07930.x
https://pubmed.ncbi.nlm.nih.gov/23200507/
https://www.karger.com/Article/FullText/442612
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3169900/
https://www.frontiersin.org/articles/10.3389/fnins.2010.00175/full
https://pubmed.ncbi.nlm.nih.gov/19039089/
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