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 is freed from nearly all impurities, ions, minerals, trace elements, organic substances, bacteria, and pollutants through the distillation process. Unlike natural spring water or tap water, distilled water contains no dissolved salts or microorganisms - it is practically pure H₂O.
This high degree of purity makes distilled water indispensable in sensitive areas 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 cause problems. 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 water or tap water, always contains various ions, trace elements, and impurities. Distilled water, on the other hand, is considered one of the highly purified waters, as it is free of these substances. 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 steam 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 less costly to produce. In warm, water-scarce 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 significantly over the centuries. While simple devices such as alembics were used in the past, complex distillation systems are used today to enable 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 obtained 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/germs | 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.
Since it is free from impurities, it ensures reliable and reproducible results in experiments. In medicine, distilled water is used to prepare infusion solutions and sterilize instruments.
In biology and chemistry, distilled water is indispensable 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.
Uses and production of distilled water
Distilled water plays an important role both in the household and in specialized industrial and scientific fields. In everyday use, it is primarily used in devices 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 special 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 needed 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 limescale and can therefore distort measurement results. The Aqua Bidest from Medicalcorner24® has an ideal conductivity of < 0.2µS.
In pharmacy, medical technology, and laboratories, distilled water is indispensable. 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 conventional 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 of 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 transitions into a vapor state
2 . The steam is then diverted and condensed on a cool surface, turning back into water.
3. This collected water is generally free of dissolved solids and other impurities.
4 . However, small amounts of volatile organic compounds may remain in the water during the distillation process, which in some applications necessitates multi-stage distillation 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 environmental concerns, as the intensive energy input and the resulting CO₂ emissions must be viewed critically in times of climate change. These factors lead to a continuous search for more efficient and environmentally friendly water purification methods.
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 equipment; widely used in general practices, dental practices, and beauty care facilities),
- Wound cleaning, 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 medications),
- Operation of devices such as ultrasound machines, endoscopes, dental instruments, oxygen concentrators, or CPAP devices (prevents deposits and ensures hygienic humidification).
Bidistilled water is particularly in demand here 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 injections (Aqua ad iniectabilia) must be produced by distillation to ensure the highest purity and sterility - a requirement strictly observed in German medical practices and pharmacies.
Environmental aspect of distillation
The production of distilled water is energy-intensive because the water must be heated to boiling temperature. This results in a higher CO₂ footprint compared with alternatives such as reverse osmosis or ion exchange. Depending on the plant, 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 using waste heat.
In addition, hybrid systems (e.g., combined with photovoltaics) promote not only water production but also electricity generation, 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 is the effect of distilled water on the body
Our bodies consist mainly of water and require essential amino acids, minerals, and trace elements to maintain their 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 if you drink only water that contains no minerals or trace elements?
It is often claimed that consuming distilled or desalinated water can be dangerous. This complex issue requires differentiation. Consuming distilled water normally poses no acute health risks as long as it is drunk in usual quantities.
However, excessive consumption combined with an unbalanced diet can cause distilled water, like regular water, to result in 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 that are important for the body.
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, especially with 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. With a balanced diet and moderate consumption, however, distilled water is harmless.
Myths surrounding distilled water
A widespread myth claims that drinking distilled water causes cells to “burst” through osmosis. This is false: This effect occurs only when it is injected directly into the bloodstream (a hypotonic solution causes hemolysis). 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 level of hygiene; and in industry, it contributes to the longevity 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 pathways. In an era 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 impurities such as salts, minerals, and organic substances. It is already very pure and is frequently 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 impurities 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 drinkable?
Distilled water is drinkable and completely safe in moderate amounts (e.g., for tea or coffee) - it is free of pollutants and germs. However, it contains no minerals such as calcium, magnesium, or potassium, which the body needs and normally obtains through food. When used as the sole source of drinking water over the long term, it 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 deficiency could develop with a one-sided diet, potentially leading to 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 distortions; 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 therapies would be impossible, as ordinary water could interfere through minerals or contaminants.
Can you make distilled water yourself (how do you 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 is as follows: boil the water, cool the steam (e.g. by running cold water around the tube), and collect the condensate. However, the process requires time (hours for small quantities), energy, and clean materials to prevent contamination - otherwise, the result will not be pure. For household use, this is sufficient for small quantities (e.g. for an iron), but industrial versions are more efficient and purer. Tip: Use filtered starting 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, watering plants (short-term), 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 devices). 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 should not be used long-term for aquariums (the lack of minerals harms fish) or plants (growth problems). Alternatives such as remineralized reverse-osmosis water are often more practical for everyday use and drinking. In medical practices, it is 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 obtains minerals primarily 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 safe 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 with 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-supply retailers, 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. Large containers (e.g., 5–20 liters) are available for medical practices and laboratories. Recommendation: Buy from trustworthy suppliers to ensure purity and sterility.
Can you drink purchased distilled water?
Yes, purchased distilled water is drinkable and safe because it is free from 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-rich water. Many people use it for tea, coffee, or baby food (after consulting a doctor) because it is neutral in taste 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 (the pH drops slightly) or become contaminated - in that case, use it within a few weeks. Tip: Store it in a cool, dark, sealed place (e.g., in the 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 (which act as nucleation sites), it can become supercooled - remaining liquid down to -10 °C or lower until a disturbance (e.g., shaking) triggers sudden freezing. This is an interesting physical effect used in experiments, but it is harmless in everyday life.
