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Why Does Carbonated Water Taste Bitter?

Why Does Carbonated Water Taste Bitter?

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For some, the strange bitter flavor of carbonated water can be off putting. When carbonated water is combined with other flavors and drinks, the bitter taste is not noticeable.

But when you drink carbonated water itself, it can be hard to ignore.


One theory as to why carbonated water tastes bitter is that it’s a reaction from the feeling of the bubbles from the water popping in your mouth. However, this theory has since been disproved based on scientific studies.

These studies looked into what exactly caused the bitter taste, and found that it wasn’t a reaction to the bubbles popping. They found this out when they did studies of people drinking carbonated water that had gone flat.

The flat carbonated water still produced the same bitter taste that the carbonated water that still bubbled did.

After finding out that the bubbles weren’t the reason that carbonated water tastes bitter, researchers started to look into other reasons that carbonated water might have a strange flavor that not everyone likes.

Flavor Receptor Research

The strange flavor that you may be tasting in carbonated water comes from the carbon itself. There is some scientific evidence that the ability to taste the carbon in the water might be something that developed over time, and is linked to genetics.

In a study done on mice, researchers found that mice that were unable to taste sour flavors were also not able to taste any distinct difference in the taste of carbonated water when compared to regular, flat water.

They also found that the ability to taste sour flavors was programmed into the genetic code of mice. The way that this caused the mice to be able to break down the carbonated water led to the bitter flavor.

Carbonated water tasting bitter could come from this gene that was found in mice. The reason that it developed was to help differentiate between food that was good and food that had spoiled, making it genetically advantageous to have this ability.

So, while carbonated water isn’t spoiled, it could be bitter because it’s triggering a system in your body that was designed to detect food that had gone bad.

CO2 Causing Bitterness

Carbon dioxide (CO2) is what makes carbonated water fizzy. This is the substance that also makes the water taste bitter.

In the same study as mentioned above, which used mice as test subjects, researchers studied the effects of CO2 versus regular carbonated water. The researchers gave the mice both carbonated water and exposed them to CO2 in its gaseous state.

Both of these substances triggered the same physiological response that the carbonated water produces.

The CO2 was able to trigger nerve receptors. They were able to find out that it was linked to detecting sour flavor by tracking the receptors. The gene that is linked to sour taste receptors is called Car4.

Car4 works to create the bitterness that you taste when you drink carbonated water by converting the CO2 in the water to bicarbonate ions and protons. Those protons are what causes the bitterness in CO2, which is then what causes the bitter taste in carbonated water.

Does Carbonated Water Taste Sour?

You’re probably wondering why carbonated water is detected by taste receptors that only sense sour flavors. If carbonated water tastes bitter, wouldn’t it also have to taste sour to be detected by those sour receptors?

The short answer is no, carbonated water does not taste sour.

The reason why carbonated water is detected by sour taste receptors, which in turn makes the carbonated water taste bitter, is that there are other factors in play.

It’s not known for certain, but researchers theorize that the sensation of the bubbles in the carbonated water are what makes the water taste bitter and not sour.

So, while the bitter flavor of carbonated water isn’t necessarily due to the carbonation, the carbonation does have an influence on how our bodies taste the CO2.

Is Carbonated Water Painful?

Some people don’t like carbonated water because of how the bubbles feel, rather than because of the bitter taste of the water.

It might be unpleasant for them to drink anything that has carbonation, including sodas where the flavor and syrups added to the carbonated water cancel out any bitter flavor that you might have been able to detect in plain carbonated water.

It might be confusing to you if your friend hates carbonated water or beverages because they hurt, but you enjoy the bubbles. The way that the bubbles pop in your mouth could possibly lead to feeling pain, but it depends on the way that your individual body and system processes the stimulus.

When there’s a stimulus like carbonated water, bodies react in a way that might not seem like a logical response to something as harmless as little bubbles in water. There are different ways that your body might react to pain, which is triggered when you drink carbonated water.

Drinking carbonated water might cause things such as coughing, watery eyes, sneezing, and even feeling pain in your nose. These responses don’t happen in everyone, but when you consider this it makes it easier to understand why someone would think that carbonated water is too painful to actually be something that they would enjoy drinking.

Why Do Some People Like Carbonated Water?

If you are wondering why some people like to drink plain carbonated water even though it tastes bitter and can cause some people to feel pain, remember that everyone is different. There are many factors that go into what kinds of tastes that different people like.

For some people, they might not be bothered by the bitter taste. Some might even taste the bitterness in the carbonated water more or less than others, which might be why people make different choices about whether or not they would want to drink carbonated water or other carbonated beverages.

When it comes to the pain response to drinking carbonated water, remember that some people feel this more than others. Different bodies process the sensation of the carbonated water in different ways, so some people might actually like the carbonation while others would interpret the carbonation as painful.

Why Don’t Carbonated Drinks Taste Bitter?

Carbonated water itself might have a bitter taste, which some people find to be unpleasant. If you don’t like to drink carbonated water, but you do like to drink soda, this might be a bit confusing when you think about it.

The bitter taste in carbonated water is CO2, which is still present in different carbonated drinks such as soda.

The reason that you wouldn’t be able to detect the same bitterness in a flavored carbonated drink is that the other ingredients are able to mask the flavor of the bitterness.

When you drink something that has carbonated water in it, the other flavors and ingredients in the drink are added in large enough portions so that they are able to mask and overpower any bitter taste that the carbonated water has.

So, it’s perfectly normal to dislike the taste of carbonated water, while still being able to enjoy drinks that have carbonated water as an ingredient.

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