Distilled water, also known as Aqua Dest or Aqua Bidest (when distilled twice), is one of the purest forms of water. It is highly purified water that has been freed from nearly all impurities, ions, minerals, trace elements, organic substances, bacteria, and pollutants through the distillation process. Unlike natural spring or tap water, distilled water contains no dissolved salts or microorganisms - it is virtually pure H₂O.
This high degree of purity makes distilled water indispensable in sensitive fields such as medicine, pharmaceuticals, chemistry, and laboratories. It serves as an ideal solvent and cleaning agent because it leaves no residue and does not distort experiments or processes. It is also valued in industry and households, where limescale deposits or impurities could be problematic. The question “What is distilled water?” is often asked when the highest water quality is required - and the answer lies in its unique purity achieved through physical separation.
Natural water, such as spring or tap water, always contains various ions, trace elements, and impurities. Distilled water, on the other hand, is considered highly purified water because it is free of these additives. In medicine, pharmaceuticals, chemistry, and biology, it is used as a solvent and cleaning agent and enables the extraction and further processing of intermediate products.
The production of distilled water takes place in a closed system, where water is heated until it evaporates. The vapor is then passed through a counterflow cooler, such as a Liebig condenser, where it is cooled and condensed. The resulting condensate, also known as distillate, is collected in a separate vessel.
However, its production is energy-intensive and therefore expensive, which is why demineralized water is often preferred for everyday applications such as batteries or irons, as it is more ecological and cost-effective to produce. In water-scarce, warm regions, distilled water is also obtained from seawater by evaporating it using solar energy in glazed facilities and condensing it on sloped glass roofs, with the stored heat enabling production at night as well.
History of distillation
Distillation has a long history dating back to antiquity. Distillation was already used in ancient Egypt and Greece to produce essential oils and perfumes. The earliest known distillation methods were further developed by Arab alchemists in the 8th century, who used them to obtain alcohol and medicinal substances. In the Middle Ages, distillation became popular in Europe, particularly for producing spirits and medicines. Today, distillation is a fundamental process in chemistry, medicine, and industry.
Modern distillation technology has evolved considerably over the centuries. While simple devices such as alembics were used in the past, complex distillation systems are used today, enabling precise control of temperature and pressure. This has revolutionized the production of highly pure distilled water for medical and scientific purposes.
Distilled vs. bidistilled water
Distilled water is produced through a single distillation process that removes impurities such as salts, minerals, and organic substances. It is frequently used in households, laboratories, and industry. Bidistilled water, on the other hand, undergoes a second distillation process to achieve even greater purity. This water is particularly important in medicine, pharmaceuticals, and highly sensitive scientific applications, where even the smallest impurities can cause problems.
The main difference between distilled and bidistilled water lies in their purity. While distilled water is already very pure, bidistilled water contains virtually no impurities. This makes it ideal for applications such as preparing injection solutions or cleaning laboratory equipment.
Distilled, bidistilled, demineralized, and osmosis water - differences at a glance
| Type of water | Purity level | Process | Removes organic substances/microorganisms | Typical applications | Energy consumption/costs |
|---|---|---|---|---|---|
| Distilled water | Very high | Simple distillation | Yes | Households, laboratories, industry, medicine | High |
| Bidistilled water | Highest | Double distillation | Yes (even more thorough) | Pharmaceuticals, injections, high-precision analyses | Very high |
| Demineralized water | Medium to high | Ion exchange or similar | No | Irons, batteries, car radiators | Low |
| Osmosis water | High | Reverse osmosis (membrane filtration) | Partially (with post-treatment) | Drinking water filters, aquariums, laboratories | Medium |
Scientific applications
Distilled water plays a central role in science. It is used in laboratories to prepare solutions, calibrate equipment, and clean glassware.
Because it is free of impurities, it ensures reliable and reproducible results in experiments. In medicine, distilled water is used to prepare infusion solutions and sterilize instruments.
Distilled water is indispensable in biology and chemistry because it contains no ions or organic compounds that could distort experimental results.
It is also used in the electronics industry to clean sensitive components because it leaves no mineral residues.
Application and production of distilled water
Distilled water plays an important role both in the home and in specialized industrial and scientific fields. In everyday use, it is mainly used in appliances such as steam irons because it contains no minerals that could cause limescale deposits.
This purity also makes it ideal for cleaning sensitive surfaces such as glass or specialized tools where residues are undesirable.
Industry mainly requires distilled water as a cleaning agent and solvent. Aqua Bidest - double-distilled water - is used primarily in the medical and pharmaceutical fields. For example, it is required for the production of colloidal silver.
In chemistry, work is carried out almost exclusively with Aqua Dest or Aqua Bidest, as ordinary water contains too much lime and can therefore distort measurement results. The Aqua Bidest from Medicalcorner24® has an ideal conductivity of < 0.2µS.
Distilled water is indispensable in pharmacy, medical technology, and laboratories. It is used to manufacture medicines, for medical tests, and in biochemical experiments where any contamination could distort the results.
Due to its high purity, distilled water is also ideally suited for microbiological cultures and analytical procedures that require a contamination-free environment.
Modern production methods include not only classic steam distillation but also multistage systems and, increasingly, solar distillation in sunny regions to save energy.
Of course, you can also buy distilled water here and learn more about bidistilled water in the Medicalcorner24® online shop.
The production process for distilled water
Distilled water is produced through the distillation process, which is one of the oldest and most effective methods of water purification.
1 . This process begins by heating water until it changes into a vapor
2 . The steam is then diverted and condensed on a cool surface, turning back into water.
3. This collected water is generally free from dissolved solids and other contaminants.
4 . However, small amounts of volatile organic compounds may remain in the water during the distillation process, which in some applications makes multistage distillation necessary to guarantee the highest possible purity.
5 . Despite its many advantages, water distillation also has disadvantages, particularly its high energy consumption. This not only makes the process costly, but also raises ecological concerns, as the intensive energy input and the associated CO₂ emissions must be viewed critically in times of climate change. These factors lead to a continuous search for more efficient and environmentally friendly methods of water purification.
Distilled water in medical practices and healthcare facilities
In medical practices, clinics, pharmacies, and medical laboratories, distilled water (often referred to as Aqua Dest or Bidest) is indispensable for the highest hygiene and purity standards. It is used for:
- Sterilization of instruments (e.g., in autoclaves and small steam sterilizers, where low-mineral water prevents limescale deposits and extends the service life of the devices; widely used in general practices, dental practices, and beauty care facilities),
- Cleaning of wounds, medical devices, and laboratory equipment (free from germs, pyrogens, and residues to minimize contamination),
- Dilution of medications and preparation of solutions (e.g., for inhalation therapies, infusions, eye drops, or parenteral medicines),
- Operation of devices such as ultrasound devices, endoscopes, dental tools, oxygen concentrators, or CPAP devices (prevents deposits and ensures hygienic humidification).
Double-distilled water is particularly sought after in this context because it is required for injectable preparations or sensitive procedures. In medical practices, it reduces the risk of contamination and extends the service life of expensive medical equipment. According to the European Pharmacopoeia (Ph. Eur.) and the German Pharmacopoeia (DAB), water for injection (Aqua ad iniectabilia) must be produced by distillation to ensure the highest level of purity and sterility - a requirement strictly observed in German medical practices and pharmacies.
Ecological aspects of distillation
The production of distilled water is energy-intensive because the water must be heated to boiling temperature. This results in a higher carbon footprint compared with alternatives such as reverse osmosis or ion exchange. Depending on the system, energy consumption can amount to several kWh per liter, causing significant emissions in large-scale production.
In times of climate change, this aspect is increasingly viewed critically: Fossil fuels used for heating contribute to global warming. Modern approaches, such as solar distillation plants or energy-efficient multistage systems, significantly reduce this impact. In sunny regions, solar stills enable environmentally friendly production without fossil fuels - studies show that solar distillation can reduce CO₂ emissions by up to 70–80% while also utilizing waste heat.
In addition, hybrid systems (e.g., combined with photovoltaics) not only promote water production but also generate electricity, improving the overall balance. For everyday use, experts recommend using distilled water sparingly and turning to alternatives where possible to minimize the ecological footprint.
What are the effects of distilled water on the body
Our body consists mainly of water and requires essential amino acids, minerals, and trace elements to maintain its functions, most of which we obtain through our diet. It is often recommended to drink plenty of water or nutrient-rich fluids to stay hydrated, supplied with minerals, and capable of performing well.
But what happens when you drink only water that contains no minerals or trace elements?
It is often claimed that consuming distilled or demineralized water can be dangerous. This complex issue requires differentiation. Consuming distilled water normally poses no acute health risks as long as it is consumed in usual amounts.
However, excessive consumption combined with an unbalanced diet can cause distilled water, like regular water, to lead to water intoxication. It is particularly dangerous when such water enters the bloodstream directly, for example through an infusion, as this can cause cell damage due to osmosis. Nevertheless, tap or mineral water is generally healthier because it contains the salts the body needs.
According to the World Health Organization (WHO) and studies on demineralized water (e.g. Kozisek, 2005), long-term exclusive consumption can lead to a slight deficiency in minerals such as calcium, magnesium, and potassium, particularly in the case of an unbalanced diet. This potentially increases the risk of electrolyte disturbances. The German Nutrition Society (DGE) also warns against exclusive consumption, as it can lead to electrolyte depletion in the case of an unbalanced diet. However, distilled water is harmless when consumed moderately as part of a balanced diet.
Myths surrounding distilled water
A widespread myth claims that drinking distilled water makes cells “burst” through osmosis. That is false: This effect occurs only when it is injected directly into the bloodstream (a hypotonic solution causes haemolysis). When drinking normally, the water mixes with food and saliva in the stomach, so no dangerous osmosis occurs. Distilled water also does not actively “draw” minerals from the body - another myth.
Distilled water: An indispensable companion in the modern world
Distilled water has evolved from an alchemical curiosity into an essential part of everyday life and high technology. In households, it prevents limescale in appliances; in laboratories and medical practices, it ensures precise results and the highest hygiene standards; and in industry, it helps extend the service life of sensitive systems. Its unique purity makes it indispensable wherever compromises in quality are not possible.
Despite the ecological challenges posed by energy-intensive production, innovative approaches such as solar distillation are opening up new, sustainable avenues. At a time when purity and precision are becoming increasingly important - from medicine and research to environmentally conscious households - distilled water remains a symbol of the highest water quality.
Whether as Aqua Dest for daily use or Bidest for sensitive applications: it reliably supports progress and health. In the future, its role will only grow through greener technologies.
FAQ: Frequently asked questions about distilled water
What is the difference between Aqua Dest and Aqua Bidest?
Aqua Dest (distilled water) is produced through a single distillation process that removes contaminants such as salts, minerals, and organic substances. It is already very pure and is commonly used in households, laboratories, and industry - ideal for applications requiring high, but not the highest possible, purity. Aqua Bidest (bidistilled water) undergoes a second distillation process to achieve even greater purity. This water is particularly important in medicine, pharmaceuticals, and highly sensitive scientific applications, where even the smallest contaminants can cause problems. The second pass also removes possible residues of volatile substances and ensures conductivity below 0.2 µS/cm. In practice (e.g., according to Ph. Eur.), Aqua Bidest is often preferred for injectable solutions, while Aqua Dest is sufficient for cleaning and general laboratory use.
Is distilled water safe to drink?
Distilled water is safe to drink and completely safe in moderate amounts (e.g., for tea or coffee) - it is free of harmful substances and germs. However, it contains no minerals such as calcium, magnesium, or potassium, which the body needs and normally obtains through food. In the long term, using it as the sole source of drinking water may contribute to a mineral deficiency if the diet is unbalanced (WHO report on demineralized water, Kozisek 2005). Studies show that the body efficiently absorbs minerals from food, but a restrictive diet could lead to a deficiency, which may cause fatigue or electrolyte disturbances. Recommendation: Yes as a supplement (e.g., occasionally), but no as the main source - it is better to choose mineral or tap water, which provides natural minerals. For infant formula or certain diets, consult a doctor.
What scientific applications does distilled water have?
Distilled water plays a central role in science and medicine. It is used in laboratories to prepare solutions, calibrate equipment, and clean glassware because it leaves no ions or residues and thus ensures precise, reproducible results. In analytical chemistry, it prevents measurement interference; in microbiology, it creates sterile conditions for cultures. In medicine, it is used to prepare infusion solutions, sterilize instruments, and dilute medications. Other areas include pharmaceutical production (e.g., colloidal silver), biotechnology, electronics cleaning, and highly precise analyses. Without distilled water, many experiments and treatments would be impossible, as ordinary water could cause interference through minerals or contaminants.
Can you make distilled water yourself (how do I make distilled water)?
Yes, you can make distilled water at home by heating water, collecting the steam, and condensing it - this is the principle of distillation. You need a distillation apparatus (e.g., made of glass or stainless steel) or improvised equipment such as a pot with a lid, a bowl inside the pot, and a tube to direct the steam into a collection vessel. The process: boil the water, cool the steam (e.g., with cold water around the tube), and collect the condensate. However, the process requires time (hours for small quantities), energy, and clean materials to avoid contamination - otherwise, the result will not be pure. For household use, this is sufficient for small quantities (e.g., for an iron), but industrial systems are more efficient and purer. Tip: Use filtered source water and disinfect all parts. For medical purposes, it is better to buy ready-made distilled water, as home distillation does not guarantee sterility.
What is distilled water used for?
Distilled water has a wide range of applications thanks to its purity: at home, for steam irons (prevents limescale), humidifiers, car batteries, short-term plant watering, and cleaning sensitive surfaces (e.g., glass, without streaks). In industry and medicine, it is used for sterilization, medication production, laboratory experiments, inhalation therapies, and operating equipment (e.g., ultrasound machines). Practical tip: Store it in clean, sealed glass or HDPE containers in a cool, dark place to prevent recontamination by bacteria or CO₂ absorption - open bottles last only a few days. It is not suitable for aquariums long-term (the lack of minerals harms fish) or for plants (growth disorders). Alternatives such as remineralized reverse-osmosis water are often more practical for everyday use and drinking. In medical practices: indispensable for hygiene and equipment care.
What happens if you drink distilled water?
Drinking distilled water in moderate amounts is nothing dramatic - it hydrates the body like any other water. However, it lacks the minerals (calcium, magnesium, potassium) found in natural water. Long-term exclusive consumption combined with an unbalanced diet can lead to a slight mineral deficiency, causing symptoms such as fatigue, muscle cramps, or electrolyte disturbances (according to the WHO and DGE). The body primarily gets its minerals from food, so the risk is low with a good diet. It is acutely dangerous only when infused directly into the bloodstream (hemolysis). In small amounts (e.g., for coffee), it is completely harmless and even beneficial because it is free of contaminants.
What pH does distilled water have?
Distilled water theoretically has a neutral pH of around 7.0 because it is pure H₂O. In practice, however, it can become slightly acidic by absorbing CO₂ from the air (pH 5.5–6.5), which produces carbonic acid - a natural process that occurs in all water. This is completely harmless and affects neither its purity nor its use. The pH stabilizes quickly, making distilled water ideal for sensitive processes where a neutral medium is required.
Where can I get distilled water for medical purposes?
Distilled water for medical purposes (bidistilled water or Aqua Dest) is available from pharmacies, specialist laboratory suppliers, online shops such as Medicalcorner24, or drugstores. Look for certifications according to Ph. Eur. or DAB for pharmaceutical quality - especially for bidistilled water intended for sensitive applications. Practices and laboratories can obtain bulk containers, such as 5–20 liters. Recommendation: Buy from reputable suppliers to ensure purity and sterility.
Can you drink purchased distilled water?
Yes, purchased distilled water is drinkable and safe because it is free of impurities and germs. It is well suited for short-term use or emergencies. However, it should not be your main source of drinking water because it lacks minerals - in the long term, it is better to switch to mineral-containing water. Many people use it for tea, coffee, or baby food (after consulting a doctor) because it is tasteless and pure.
How long does distilled water last?
Distilled water has an almost unlimited shelf life in sealed, clean containers because it provides no nutrients for bacteria. After opening, however, it may absorb CO₂ (causing a slight drop in pH) or become contaminated - in that case, use it within a few weeks. Tip: Store it in a cool, dark, sealed place, such as its original bottles. When stored properly, it remains pure for years.
When does distilled water freeze?
Distilled water freezes at exactly 0 °C, like pure water. However, because it lacks impurities that act as nucleation sites, it can become supercooled - remaining liquid down to -10 °C or lower until a disturbance, such as shaking, suddenly triggers freezing. This is an interesting physical effect used in experiments, but it is harmless in everyday life.
