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Water knowledge

Can you drink distilled water?

Is drinking distilled water dangerous, or just unnecessary? Few questions about water attract as many half-truths. The short answer: small amounts are harmless for healthy adults, and the oft-cited “bursting cells” are a myth. As an everyday drink it still makes little sense, because distilled water lacks all minerals, and with them any taste.

Updated August 2026 · 6 min read

In brief

  • Small amounts are harmless for healthy adults; the often-quoted “bursting cells” is a myth.
  • Unsuitable as an everyday drink: it lacks all minerals, and with them the taste.
  • Hardware-store or chemist’s stock is a technical product, not made as a foodstuff.

What exactly is distilled water?

Distilled water is produced by evaporating water and then condensing the vapour again. Minerals, salts and most accompanying substances are left behind; what remains is almost pure H2O. You can see this in its electrical conductivity alone: in distilled water it is close to zero, because hardly any dissolved ions remain. Rainwater, too, is naturally very low in minerals. Distillation takes this principle to its technical extreme. Closely related are demineralised and deionised water, which are desalinated using ion exchangers or reverse osmosis: the process is different, the result similar. In shops, distilled water is usually sold as technical-grade water for household appliances – a first hint that it was never intended as a drink.

Drinking distilled water: is it dangerous?

No, at least not in the quantities that matter in everyday life. Anyone who drinks a glass of distilled water need not fear any consequences: it mixes with saliva in the mouth and with food and digestive secretions in the stomach, and the body continuously balances out differences in concentration. An accidental sip while filling an appliance is no cause for concern either. Things would only become critical with very large quantities in a short time, because the body's salt balance can then be thrown off. That applies to any water, though, as the article on drinking too much water shows. There is no reason to worry, then. There is also no reason to choose distilled water deliberately as a drink.

This article provides general information. If you have health concerns or are unsure (in the case of kidney disease or a markedly altered sense of thirst, for instance), please consult your doctor.

What lies behind the myth of “bursting cells”?

The myth contains a kernel of truth, but one from the laboratory. Osmosis describes the effect whereby water moves through a semi-permeable membrane towards the side where more substances are dissolved. If red blood cells are placed directly in pure water, water therefore flows into the cells: they swell and can indeed burst – specialists call this haemolysis.

When you drink, however, this situation never arises. Distilled water does not reach the body's cells in pure form: within seconds it is mixed with saliva and stomach contents, absorbing dissolved substances as it goes. What the intestine passes into the blood is no longer pure water by any means. Besides, blood and kidneys, steered by hormones, keep the body's water and salt balance constantly in check. The laboratory observation is therefore correct; transferring it to a glass of water is not.

Why is distilled water unsuitable as an everyday drink?

The fact that distilled water is not toxic does not make it a good drink. What speaks against drinking it daily:

  • No minerals: distilled water contains no calcium, magnesium or hydrogen carbonate at all. It contributes nothing to your daily mineral intake.
  • Flat taste: the character of a water comes largely from its dissolved minerals. Without them, water tastes empty; many people find distilled water bland.
  • Not a foodstuff: distilled water sold in shops is generally a technical product. It is not produced and monitored according to the standards that apply to drinking water and natural mineral water.

Anyone planning to drink demineralised water and nothing else would be giving up minerals without need. It is not acutely dangerous; it simply brings the body nothing. If minerals matter to you, choose your water by what it contains.

What is distilled water actually meant for?

There are good reasons why distilled water is still found in every DIY store; they just have nothing to do with the kitchen. It plays to its strengths wherever dissolved substances would get in the way:

  • Household: irons, steam stations and humidifiers do not scale up when run on distilled water, unlike with hard, limescale-rich water from the tap.
  • Technology: car batteries, cooling systems and laboratories call for water of defined purity that leaves no residues or deposits.
  • Aquaristics: aquarium keepers mix demineralised water with tap water to set water hardness and conductivity precisely.

In short, distilled water is a tool for appliances and processes. It was never meant for the dining table.

What does mineral water offer that distilled water lacks?

Natural mineral water is in a sense the counter-model to distilled water: on its long journey through layers of rock it absorbs minerals that shape its profile and its taste, differently at every spring, as the comparison of spring water and mineral water shows. Calcium and magnesium from mineral water can contribute to your daily intake: the European Food Safety Authority (EFSA) gives reference values for adults of around 950 to 1,000 mg of calcium and 300 to 350 mg of magnesium per day. A water rich in minerals covers part of that quite incidentally, as you drink.

Just how strongly rock can shape a water is shown by the Castels spring in Mels: its water seeps into the ground at over 2,000 m above sea level in the Sardona Alps, by the UNESCO World Heritage Tectonic Arena Sardona, and is filtered through layers of rock and stone for around 12 years. The result is Piz Sardona, a naturally alkaline mineral water with a pH of 8.0, carrying 87 mg of calcium and 35 mg of magnesium per litre and a balanced total mineralisation of 540 mg per litre. The difference from distilled water is easy to measure and easy to taste.

Frequently asked questions

Is boiled water the same as distilled water?

No. Boiling kills germs, but the dissolved minerals and salts remain fully in the water. Distilled water, by contrast, is produced by evaporation and re-condensation, a process in which almost all dissolved substances are left behind. Boiled tap water is therefore still perfectly ordinary water, just low in germs; distilled water is almost pure H2O without any minerals.

Can you drink distilled water from the DIY store?

It is best avoided. Distilled water from DIY stores or chemists is a technical product: it is not produced, bottled and monitored as a foodstuff, and the containers are not intended for food use. If you want water to drink, you are better off with drinking water or natural mineral water; both are subject to strict food-safety regulations.

Can you cook with distilled water?

In principle, yes: there is nothing wrong with occasional use, especially as food itself supplies minerals. But there is hardly anything to be gained either. Soups, tea and coffee also draw their taste from the character of the water used, and that character comes from its dissolved minerals. Dishes prepared with distilled water therefore often taste strikingly flat.

What is the difference between distilled water and reverse-osmosis water?

Both are largely demineralised; the process differs: distilled water is evaporated and condensed again, while reverse-osmosis water is forced under pressure through a fine-pored membrane that holds back dissolved substances. Reverse-osmosis water usually still contains minimal traces of minerals. For drinking, the same assessment applies: small amounts are harmless, but neither is suitable as an everyday drink.

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Piz Sardona

Alkaline mineral water with a pH of 8.0 from the Castels spring in Mels — filtered through the rock of the Sardona Alps for twelve years.

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