Why Does Water Taste Better At Night? Science Explains Why…

clear drinking glass filled with water

Last Updated on October 9, 2022 by theworldofsleepstaff

For most of us, waking up during the night with a dry mouth or throat isn’t an unusual occurrence. When this happens, the first thought in our mind is how to get a glass a water to quench our thirst, and by the time we are gulping down that glass of water, we acknowledge that that quick trip to the kitchen was definitely worth it!

In fact, you might find yourself taking more than you usually do because suddenly, that glass of water you’re drinking tastes better and more refreshing than usual.

Many folks, including us, have often wondered why the water we drink in the middle of the night somehow tastes better.

Some people have concluded that it’s probably all just in their head. But what if we told you that there might be some evidence to actually back up your claim that water tastes better at night?

Yes, that’s right, there might actually be some logical reasons why water tastes better at night. And we’re going to show you those below.


  1. Possible Scientific Reasons Why Water Tastes Better at Night
  2. Other Reasons Why Water You Drink At Night May Taste Better
  3. Does Water Go Stale If Left Out On The Bedside Table?
  4. Why Does Water Taste More Refreshing When You Wake Up?
  5. Our Final Thoughts
woman drinking water

Possible Scientific Reasons why Water Tastes Better at Night

Do you know that there are phenomena called “dark water” and “light water”?

Both of these phenomena are an anomaly that occurs when your water is exposed to either darkness or light respectively. During the day, it seems that water absorbs daylight ions, which affects the water’s weight and temperature. So even though most people might not be aware of the difference, daylight water takes on a flat taste.

At night, when everywhere is dark, the water takes on a more refreshing taste. This is because heavier nighttime ions have displaced the absorbed daylight ions.

Most people might actually prefer dark water, even though they might not realize there’s a difference.

person holding drinking glass

Other Reasons Why Water You Drink at Night may Taste Better

1. Good Oral Hygiene

Dentists and other medical personnel count brushing your teeth at night as good oral hygiene. And if you’re one to practice it (as you should!), it might explain why the water you drink at night tastes better.

Besides the leftover minty taste of toothpaste on your mouth, brushing your teeth/ tongue will help you eliminate slime that may have accumulated over the day. This slime covers your taste buds and may not allow you to taste the flavor of some foods adequately.

However, by brushing it off, you’re exposing your taste buds and making them more sensitive to taste.

Drinking some water when your taste buds are in this state might make you sense some sort of flavor in the water that you may not have ordinarily detected.

Additionally, food particles and residue are always on our tongues after eating. When we drink water with these residues on our tongues, we might not be able to fully taste the refreshing taste of the water we drank.

For example, let’s say you had mac and cheese and then drank water afterward. Chances are you’ll still taste some measure of mac and cheese in the water you’re drinking.

Brushing makes this residue go away and exposes your taste buds to the real refreshing taste of water.

closeup and selective focus photography of toothbrush with toothpaste

2. Reward System

Do you notice how you feel particularly good after completing a task? That’s your brain’s reward system at work. It is your brain’s way of teaching and encouraging good behavior.

To reinforce a happy feeling associated with completing a task, the brain releases serotonin – also called the feel-good hormone – when you do something that makes you happy.

This reward system goes beyond just encouraging good behavior; it is extremely important for survival too. So when you do things that aid your survival and safety, the brain also releases a small dose of this compound.

This can be related to the impact of the taste of water. Waking up dehydrated and in need of water can prompt your brain to tell you that you need water to survive.

That’s because when you’re thirsty, it is your body’s way of telling you that the fluid levels in your body are low and should be replenished. Your brain knows you need water for survival, so it creates the illusion that drinking a cup of water to quench your thirst is a reward, thus stimulating the reward center and release of serotonin.

For this reason, when you taste the water, your brain will send you the impression that it tastes better in order to encourage you to keep drinking more.

technology computer head health

3. Acid Reflux

This is a condition in which the acid in the stomach keeps traveling up the throat and mouth. Acid is a drying agent, and a person with this condition might find out that they repeatedly have a dry mouth and throat with high acidity content. Another prominent symptom of acid reflux is a sour taste in the mouth.

When the person wakes up in the night to drink water, that person may find out the water tastes better. This is mainly because of 2 reasons. First, the water will wash away the sour taste; and secondly, it will also reduce the acidity in the person’s mouth or throat.

This will inadvertently make the person feel better, which might be mistaken to be the taste of the water being tastier too!

clean clear cold drink

4. Toothpaste

Toothpaste is one of the most common reasons water tastes better at night.

Many of us brush our teeth, then go to bed almost immediately. And of course, toothpaste lingers in the mouth if it remains closed. Since it’s not like you’ll be performing or singing in your sleep, this means that the taste of the toothpaste in your moth will linger more at night.

So, if you wake up at night and drink water before the taste of the toothpaste is completely gone, some traces of the toothpaste will mix with the water and may make it taste sweeter. If you use a minty toothpaste, this taste will be further noticeable.

You might wonder why this doesn’t happen when we brush in the morning. Our theory is that after we brush in the morning, we will most likely not keep our mouths closed (like we would when we go to bed). Greeting our family members and getting ready for the day may contribute to this.

Also, after brushing, most of us dash out to work or eat breakfast which will clear most of the taste and smell of the toothpaste away. These two factors will make the toothpaste taste disappear and prevent it from working as it would at night.

So, don’t be surprised if your water doesn’t taste minty during the day but tastes better at night.

white organic toothpaste tube and bamboo toothbrush on green leaf

5. Changes to Sense of Smell

It is possible to simultaneously perceive and taste things at the same time because both senses use the same airways. This is also one of the reasons our mouth will water whenever we smell something delicious!

For example, If you have ever smelled two good things at the same time, for example, Coffee and Pizza, you will probably get a phantom taste or an illusion of the combined taste in your mouth. This is primarily based on the fact that your mouth knows what pizza or coffee tastes like; this makes the taste buds respond accordingly.

Our sense of smell and taste are connected and intertwined, which is why we almost always lose our sense of taste whenever we catch a cold.

Same thing with allergies. If you are experiencing some sort of allergy that can impact your sense of smell, your taste buds will also feel the effects.

Water tasting better at night may also be linked to this phenomenon. If you’re the type whose olfactory lobes are more active at night, you may find that drinking water at night tastes better. This is, however, a rare occurrence.

woman s face

6. Diabetes

Water might taste good at night to a person that has diabetes. One of the major symptoms of diabetes is excessive urination which is a result of the body’s inability to perform its normal function of regulating blood sugar.

Since the cells in the body rely on sugar to perform some functions, regulation is an essential key to a healthy life.

Diabetes occurs when one or both of the body’s essential systems (glucagon and insulin) becomes unable to do their job. The body is kept healthy when glucagon and insulin work together to either lower or raise the blood sugar levels in the body. When one of these systems is impaired, water will taste better because it will often leave a trail of sweetness in the mouth.

The body of a diabetic person is unable to regulate sugar in the blood, and this will make the sugar end up in the mouth. So when the person wakes up to drink water, the sugary flavor in their mouth will get added to the water, making it taste better at night.

The reason this might only happen at night is because the body performs most of its digestive functions when the body is asleep. During digestion, sugar might then end up on the taste buds. Therefore, when the person drinks water during this period, it may taste better.

If you think you may have diabetes, then schedule a doctor’s appointment.

person holding black tube

7. Iron and Calcium

If you have a private well that supplies water for your house, you might discover that the water you take home tastes better than water you get elsewhere.

This may be due to the presence of iron and calcium in the well. These two minerals are common in wells that are not connected to a water treatment center and usually make the water sweeter when combined.

However, you might get an unpleasant or irritating metallic flavor if too much iron is in your water. But if the iron content is low and reacts with the calcium, it can give the water a slightly sweeter taste.

You may also find that the water tastes a bit better at night, mainly because the well has had time to fill up.

The minerals would have had time to marinate in the water since the well was untouched for a few hours. So when you wake up and take your first drink of water, it might taste a little better because there is a larger dose of iron and calcium in it.

The minerals might not have the time to accumulate during the day because you likely use more water, but at night the minerals can marinate in the water.

stainless faucet

Does water go Stale if Left Out on The Bedside Table?

Have you ever left out a glass of water on your bedside table? Did it taste a little weird when you drank it in the morning? There is a reason why it is so.

It has been proven that when you leave a glass of water out by your bed while you sleep, there might be a slight difference in taste when you drink it in the morning. Of course, this isn’t all in our heads; water does actually have a change in taste when left out for an extended period of time. But this isn’t much of a concern, as it doesn’t change in any way that has been proven harmful to health.

In a video, Discovery News explained that when water is left out for long, it absorbs small levels of carbon dioxide; this makes the PH of the water slightly lower, thereby making the water just a bit more acidic.

However, a glass of water shouldn’t be left out for long, as the more exposed it is, the greater the possibility of the water coming in contact with harmful bacteria.

close up of bottle pouring water on glass

Why Does Water Taste More Refreshing When You Wake Up?

The reason water might taste more refreshing to you when you drink it right after you wake up is that your mouth is probably dry. If you haven’t had anything to drink or eat for several hours, your mouth will probably be dry. But drinking some water will cure that dry mouth.

Additionally, drinking water on a parched throat – which you’ll most likely have when you wake up – is more refreshing than drinking it after a  meal or for drinking sake.

Why Does Water Taste Better At Night: Our Final Thoughts

Water might taste better at night due to several reasons, ranging from your toothpaste to changes in your sense of smell.

However, when water starts tasting abnormally sweet, especially when you drink it at night, it may be a sign of a serious health issue such as diabetes. If you notice this, it is in your best interest to visit your doctor or medical advisor.