Is it possible to drink boiled water several times? Is it possible to re-boil water in a kettle?

How often do we forget that the kettle has already boiled for a long time and has already cooled down, but we still can’t tear ourselves away from our favorite show? We turn the stove back on and boil the kettle again.

What happens when we boil water a second time? Although this is very important to know, it is not taught in school.

When water boils, its composition changes, which is completely normal: volatile components turn into steam and evaporate. Thus, boiled water is safe to drink.

But when the water boils again, everything changes for the worse: Boiled water is completely devoid of taste. If you boil it several times, it becomes very, very tasteless.

Some might argue that raw water also has no taste. Not at all. Do a little experiment. At regular intervals, drink tap water, filtered water, boiled once and boiled many times. All of these liquids will taste different.

When you drink the latter version (boiled many times), you will even have an unpleasant aftertaste in your mouth, some kind of metallic taste. Boiling “kills” water.

The more often the heat treatment occurs, the more useless the liquid is in the long run. Oxygen evaporates, and the usual H2O formula from a chemical point of view is actually violated.

For this reason, the name of this drink arose - “dead water”. As mentioned above, after boiling all impurities and salts remain.

What happens every time you reheat? Oxygen leaves, and so does water. Consequently, the salt concentration increases.

Of course, the body does not immediately feel this. The toxicity of such a drink is negligible. But in “heavy” water all reactions occur more slowly. Deuterium (a substance that is released from hydrogen during boiling) tends to accumulate. And this is already harmful.

We usually boil chlorinated water. When heated to 100 °C, chlorine reacts with organic substances. As a result, carcinogens are formed.

Frequent boiling increases their concentration. And these substances are extremely undesirable for humans, as they provoke cancer. Boiled water is no longer useful. Repeated processing makes it harmful.

Therefore, follow these simple rules:

• For boiling, pour fresh water each time;
• do not boil the liquid again and do not add fresh liquid to its remains;
• Before boiling the water, let it stand for several hours;
• Having poured boiling water into a thermos (for preparing a medicinal mixture, for example), close it with a stopper after a few minutes, not immediately.

Source

The water we drink must be of high quality, since our health and well-being directly depend on it. But, since we have something vaguely resembling real water in our tap, many people start boiling it twice to improve the quality. Is this really so?

Does prolonged boiling really improve the quality of tap water? Or is it still impossible to boil the kettle twice?

What happens to water when it boils?

Tap water, which we often use in everyday life, contains a lot of harmful substances. Here you can find not only chlorine, which is used for disinfection, but also various heavy compounds. Drinking such water without preliminary treatment (boiling) is strictly not recommended.

As water begins to boil, organochlorine compounds are formed. Moreover, the longer the water boils, the more such compounds are formed. Organochlorine compounds (dioxins and carcinogens) have a depressing effect on our body. And the point is not that the result can be felt immediately after drinking water of this quality. All this will accumulate in the body for quite a long time until it results in consequences in the form of chronic diseases.

You've probably noticed that boiled water tastes different. This is also the merit of dioxins; the more of them, the harder the water turns out. But at the same time, chlorine itself has a much more unpleasant effect on the body. This is why you simply shouldn’t drink unboiled water. Pediatricians even recommend boiling it for bathing babies. Chlorine can cause skin peeling, itching and other unpleasant consequences, especially in young children.

What happens if you boil water for a long time?

Here the result is natural; dioxins are formed during the boiling process, and the longer you boil, the more of these compounds will be formed. True, in order to bring their content to a critical level (in order to feel the immediate effect on your body), the liquid will have to be boiled not two, but even twenty times.


At the same time, do not forget that the taste of water changes, and accordingly, the second boiled water is already far from ideal. This will change the taste of the tea or coffee you were about to brew. Employees of various companies and offices often sin like this; they are simply too lazy to go and get water again.

Is it dangerous to boil water several times?

Unfortunately, no one can answer this question unequivocally. The concentration of organochlorine compounds increases with each boiling, but their content will not be so significant as to cause poisoning or death. Perhaps the main disadvantage of repeated boiling is the change in the taste of the water. This greatly spoils tea or coffee and prevents you from enjoying the full taste of these drinks.

At the same time, the content of microbes in boiled water (turn on the kettle at least several times in a row) decreases after the first boil. Everything that could not survive at a temperature of 100 degrees died, and what was able to survive would not be killed by the second or third boiling. The boiling point is constant and equal to 100 degrees; if you re-boil the water, the boiling point will not become higher.

Boiling also removes so-called hardness salts from water, since they have a lower boiling point. They settle on the kettle in the form of scale, as you can see for yourself.


In any case, whether to boil or not to boil water several times is up to you to decide. However, many experts believe that you cannot boil water twice, since the process of accumulation of organochlorine compounds in the body still occurs (despite the insignificant concentration), and no one knows what this can lead to in the future. So is it worth taking risks and then looking for the cause of your ailments?

If many doctors claim that boiled water is much healthier than ordinary water, then why can’t you boil it twice? It would seem that this should bring double benefits, based on simple logic. However, the subject of chemistry is more involved here, and the chemical composition of this liquid allows us to understand why it cannot be boiled twice.

Double boiling makes water heavier

To understand the question posed, you need to turn to a school chemistry course, from which most of us know that water molecules contain natural isotopes of hydrogen. When boiling, some of them turn into steam - lighter molecules evaporate. But heavy molecules, which are also part of it, settle to the bottom. Consequently, each repeated bringing of water to a boil will make it heavier, and this cannot have a positive effect on our body.

Reducing benefit

In fact, everything is not as sad as it sounds in this subtitle. It should be clarified. And again we turn to the chemical composition of the white liquid, which, in addition to distilled water, also contains a certain amount of various impurities. This is especially true for tap water, which is subject to various cleaning methods, including chlorination. So, during boiling, only water molecules can evaporate, but all these harmful impurities remain. Moreover, due to the fact that part of the liquid turns into vapor, the concentration of such impurities increases. That is why it is considered sterile, but not free from various harmful substances.

The previous two paragraphs are perfectly acceptable explanations regarding repeated boiling. However, you should not take this too seriously. In addition, this does not mean at all that from now on it is impossible to bring water to a boil at all, since this can make it heavy, and therefore harmful, and the amount of harmful substances in its composition will increase. Let's explain. The fact is that it will receive significant and noticeable changes only when it is repeatedly boiled, for example, a hundred times. But it is unlikely that anyone would need such an action. So if you need it, boil it twice without any worries.

In addition, if you prefer to boil the white liquid for the purpose of sterilization, then this does not require a second step. All harmful germs and bacteria are killed the first time because they cannot survive at such a high temperature. Moreover, if the water in the kettle is already boiled, then the next time you use it, it is enough to heat it to the desired temperature.

If you want to use boiled water to brew tea or coffee, then you do not need to bring it to a boil again. It should be brought to the “white” state, that is, when it is saturated with bubbles before boiling.

And finally, I would like to note that if you boil water twice, it may lose its pleasant and mild taste. This may cause the tea to lose its aroma, and its benefits will become less.

Human life without water is impossible. With the help of water, 100% of metabolic processes occur in the human body. Also, with the help of water, a person maintains the cleanliness of his body, things and home. The most useful is considered to be the so-called “living” water, which flows to the surface of the earth directly from natural sources, but boiling it for a long time, especially 2-3 times in a row, can change its structure so much that it becomes unfit for drinking.

So why can't you boil water twice? It turns out that this is not a matter of terrible medieval superstitions, but of the ordinary course of chemical processes. As many remember from school chemistry courses, in nature there are isotopes of hydrogen, which are also found in water molecules. If boiling water becomes a long process, the heavier molecules settle to the bottom while the lighter molecules turn into steam and escape. The same process occurs when water is boiled twice. Each subsequent boiling makes the water heavier, which is harmful to the body.

There is another reason why you should not boil water twice. Any water (the only exception is distilled water) contains a certain amount of impurities. This is especially true for tap water that has gone through chlorination and other purification methods. As a result of boiling, water molecules (not all, of course) evaporate, and the concentration of impurities in the liquid thus increases.

All this answers the question why you can’t boil water twice. However, you shouldn’t take this so seriously that “I’d rather die, but I won’t drink twice-boiled water.” The golden mean and balance are good in everything.

So, if you look back at school chemistry textbooks, you can find problems in them to determine the number of times water is boiled in order to increase the concentration of heavy water. Solving such problems suggests that in order to achieve a more or less satisfactory result, water must be boiled 100 or more times. And it’s unlikely that anyone will dare to boil water at home more than 100 times in a row. Therefore, you can boil water twice - it will not cause serious harm to the body.

However, people are different. And if one group of people is worried about whether it is possible to drink water that has been boiled twice, then members of another group, on the contrary, are worried about whether it is possible to drink water that has been boiled only once. In this regard, we want to reassure you: if you boil water to sterilize it, then you can safely drink water that has been boiled once, because all the bacteria have already died during this process, and there is no need to perform the procedure a second time.

If you are not particularly worried about dangerous, very dangerous bacteria, then you don’t have to bring the water to the boiling point, but simply heat it to the desired temperature. By the way, in order for tea or coffee to be brewed successfully, you can simply heat the water to a “white” color - everything will brew well. It is interesting that water that is almost ready to boil acquires a “white” color as a result of the approach of saturated steam in its structure to the heated water, when the abundance of bubbles colors it white.

However, in fairness, it is worth noting that water boiled twice becomes less pleasant to the taste. So, don’t be lazy, since water is not in short supply now, and you can safely pour boiled water into the sink once and fill the kettle with fresh water from the tap.

Mom, why are you boiling water?
- So that the microbes die.
- Do you want me to drink tea with dead germs?)))

Let’s say right away that repeated boiling of water in itself does not bring much harm, but there will be no benefit either.
So why shouldn’t you boil water again or add raw water to already boiled water and boil it together? Let's look at the main opinions.

1. Heavy water.
During prolonged boiling, large masses of water evaporate from water and in this way the proportion of “heavy” water D2O increases. Heavy water settles at the bottom of the kettle. Therefore, if you do not pour out the remaining boiled water, but add fresh water to it, then when boiling again, the percentage of heavy water in this vessel will increase even more. By repeatedly adding new quantities of fresh water to the remains of old boiled water, a fairly large concentration of heavy water can be obtained. And this is dangerous for human health. If you boil the same water for a long time, it becomes “heavy” - like treated water from nuclear reactors.

Heavy water is water with deuterium (deuterium oxide). Deuterium- heavy hydrogen, designated by the symbols D and 2H. Deuterium is also found in small doses in ordinary water (1:5500). The increase in the concentration of heavy water, even during prolonged boiling, is so insignificant that it lies beyond the sensitivity of the body and can only be detected by precise equipment. An increase in concentration does not mean an increase in the amount of heavy water itself.

Heavy water(also deuterium oxide) - this term is usually used to refer to heavy hydrogen water. Hydrogen heavy water has the same chemical formula as ordinary water, but instead of atoms of the usual light isotope of hydrogen (protium), it contains two atoms of the heavy isotope of hydrogen - deuterium. The formula for heavy hydrogen water is usually written as 2H2O. Externally, heavy water looks like ordinary water - a colorless liquid without taste or smell.
However, heavy water is not as poisonous as many people think. A person can drink a glass of pure 100% heavy water without any visible harm to health; all deuterium will be removed from the body in a few days.

Experiments on mammals have shown that tangible consequences for the body occur at very high concentrations of deuterium in tissues (25%-50%). A person weighing 70 kg should drink 3 liters of 100% heavy water daily for a week so that its concentration in tissues is 25%.

The final answer will be given to us by the school problem book in chemistry for the 11th grade. One of the problems contains a quote from Pokhlebkin’s book “Tea”, where the author writes about “heavy water”, the inadmissibility of making tea from it and the need to pour new water into the kettle every time. Next, the authors of the problem book ask: how many times do you need to add water and boil it in a 1.5-liter kettle so that the concentration of heavy water increases 10 times? There are all sorts of moles, shares, X's and, finally, the answer. “To increase the content of heavy water by 10 times, you need to evaporate half of the water 157 times in a row, that is, reduce its original amount by some unimaginable number of powers, which seems meaningless.” So calmly drink tea from water that has been boiled several times!

2. Reduction of oxygen in water.

The statement that it is impossible to boil water twice, because it “becomes less oxygen” is not true. There is as little oxygen in fresh boiled water as in twice-boiled water - and several times less than in water, say, 90 degrees. There is no supersaturated solution of oxygen in water under normal conditions, so neither the number of boils nor the rate of heating of the water is important.

3. Increase in salt concentration.

There is an opinion that when boiling again in water, the concentration of either just salts or salts of heavy metals increases and all this is very harmful, of course. With each boiling, the water evaporates and the concentration of dissolved salts in the residue increases. Moreover, everything depends on the purity of the source water; if the water is clean, you boil it no matter how much, nothing will happen.
This is wrong. All salts of reversible hardness disintegrate during the first boiling. When water is heated, hardness salts rapidly decompose with the release of carbon dioxide - this explains the “whitening” of the water and the release of a large number of small bubbles before boiling. Accordingly, boiled water, as a rule (with the initial presence of significant reversible hardness, is softer than unboiled water, but how many times the water was boiled is not important.

3. The water becomes “dead”.

Filtered water is “living”, i.e. saves because "information structure" of running water. Boiled, accordingly, is lifeless. (Not to be confused with “dead” acidic and “living” alkaline water after hydrolysis!) This is well felt by animals who are more willing to drink running water from a tap (even with chlorine!) or a filter (as well as from puddles and open reservoirs), than boiled from a kettle. This is not officially recognized by science. So to believe or not to believe is your choice.

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So, of course, water can be boiled again, but from the point of view of benefits, it is most beneficial to drink filtered water, but not boiled water. For tea and coffee, it is enough to heat the water to 80 degrees. And if you boil water, do not immediately from the tap! The water must sit for the chlorine to evaporate, as has already been written about here