Is Distilled Water Better or Purified? A Comprehensive Guide

November 30, 2025 •

5 min read

According to the U.S. Environmental Protection Agency (EPA), both distilled and purified water must meet rigorous safety standards, but their differences are crucial. Navigating the choice of is distilled water better or purified depends heavily on the intended application and your specific needs.

Quick Summary

Distilled water is created by boiling and condensing steam, removing virtually all impurities and minerals. Purified water uses various filtration methods like reverse osmosis, removing contaminants but potentially retaining some beneficial minerals. The best choice depends on its specific use, from drinking to medical applications.

Key Points

Process Defines Purity: Distilled water is boiled and re-condensed, removing nearly everything; purified water uses filtration methods like reverse osmosis, which can retain some minerals.
Mineral Content Matters: Distilled water contains virtually no minerals, while purified water can be treated to keep beneficial minerals like calcium and magnesium.
Daily Drinking vs. Specialized Uses: Purified water is generally better for daily drinking due to its taste and mineral content, whereas distilled water is essential for medical equipment, labs, and certain appliances.
Flavor Profile: Distilled water has a noticeably flat taste from the absence of minerals, while purified water tends to taste cleaner and more pleasant.
Health Impact: While both are safe for consumption with a balanced diet, long-term sole reliance on distilled water can remove beneficial mineral intake, which is retained in many purified options.
Energy and Cost: Distillation is an energy-intensive process, making purified water production often more energy-efficient, though system costs and maintenance vary.

What Is Distilled Water?

Distilled water is created through the process of distillation, an age-old method of water purification. This process involves boiling water to create steam and then collecting and condensing that steam back into a liquid form. All impurities, including minerals, salts, and non-volatile organic compounds, are left behind in the boiling vessel. This results in water with extremely high purity, often with a total dissolved solids (TDS) content of less than 10 ppm, and often closer to 0 ppm. Because it is essentially pure H2O, it has a flat, almost tasteless quality.

Benefits of Distilled Water

Highest Purity: Distillation is one of the most effective ways to remove a wide range of contaminants, including bacteria, viruses, lead, and sulfates.
Ideal for Equipment: Because it lacks minerals, distilled water is perfect for use in appliances that can be damaged by mineral buildup, such as steam irons, CPAP machines, and humidifiers.
Laboratory and Medical Use: The high purity is essential for scientific experiments and medical procedures where any mineral or contaminant could interfere with results or cause complications.

Drawbacks of Distilled Water

Lacks Minerals: The distillation process removes beneficial minerals like calcium and magnesium that are important for human health.
Energy-Intensive Production: The boiling process requires a significant amount of energy, making large-scale production costly and less environmentally friendly compared to other methods.
Potential for Issues: For daily drinking, relying solely on distilled water could potentially lead to mineral deficiencies if not supplemented by a balanced diet.

What Is Purified Water?

Purified water is water that has been treated to remove impurities and contaminants to meet specific purity standards. The definition of purified water is a legal standard, typically requiring that water has a TDS of less than 10 ppm. However, unlike distilled water, purified water can be produced using a variety of methods, including reverse osmosis, deionization, and activated carbon filtration. These methods are often used in combination to achieve the desired level of purity. Critically, purified water processes can be designed to retain some beneficial minerals, unlike the complete stripping that occurs with distillation.

Benefits of Purified Water

Enhanced Taste: By removing bad-tasting chemicals like chlorine while retaining some minerals, purified water often has a cleaner and more pleasant taste.
Safer for Drinking: It removes many common contaminants and heavy metals, providing a safer drinking option than untreated tap water.
Balanced Mineral Content: Many purified water brands aim to retain healthy mineral content, offering a more balanced drink for everyday consumption.

Drawbacks of Purified Water

Variable Purity: The final purity can depend heavily on the specific filtration methods used, meaning not all purified water is equal.
Waste Generation: Some purification methods, like reverse osmosis, can create significant water waste.
Maintenance Needs: Home purification systems require regular filter replacement, which is a recurring cost and a maintenance task.

Distilled vs. Purified Water: The Main Differences

The core difference lies in the process and the final mineral content. Distillation is a physical phase change (boiling and condensing), ensuring near-total removal of everything but H2O. Purification is a filtration process that can be fine-tuned to remove specific contaminants while potentially leaving trace minerals. The right choice depends entirely on the application.

Comparison Table: Distilled vs. Purified Water


Feature	Distilled Water	Purified Water
Process	Boiling and condensing steam.	Filtration (Reverse Osmosis, Ion Exchange, Carbon Filters).
Purity Level	Extremely high; removes virtually all impurities and minerals.	High; removes most contaminants, with TDS <10 ppm.
Mineral Content	Virtually zero.	Variable; can retain some beneficial minerals.
Taste	Flat and bland due to lack of minerals.	Often cleaner and more pleasant due to mineral retention.
Common Uses	Medical/lab equipment, CPAP machines, irons, car batteries.	Everyday drinking, cooking, food and beverage production.
Energy Use	High due to boiling process.	Lower than distillation, varies by method.

Ideal Use Cases for Each

Determining whether distilled water or purified water is better requires a clear understanding of the intended use. For daily drinking, purified water is generally the more suitable option for most people. Its balanced mineral content provides a better taste and contributes to overall health. However, for specialized needs, distilled water is the superior choice.

When to Use Distilled Water

Medical Equipment: Use in devices like Continuous Positive Airway Pressure (CPAP) machines is crucial to prevent mineral build-up that can clog or damage the machine.
Scientific and Lab Settings: Experiments requiring an absolute pure water base to avoid mineral interference rely on distilled water.
Household Appliances: Steam irons, car batteries, and humidifiers all benefit from distilled water to avoid mineral deposits and prolong their lifespan.

When to Use Purified Water

Daily Drinking: A great option for ensuring your hydration is free from common contaminants found in tap water while still getting some beneficial minerals.
Cooking: Use purified water to ensure the purest flavors in your food and beverages.
Infant Formula: In many cases, purified water is a safe and readily available option for mixing with baby formula.

Potential Health Considerations

While both options are safe for consumption, their differing mineral contents lead to different health implications. With a balanced diet, the lack of minerals in distilled water is not a health concern, but it should not be relied upon as a primary source of hydration without considering mineral intake from other sources. In contrast, purified water, which retains some minerals, offers a more familiar and potentially more beneficial mineral profile for daily drinking. For individuals with compromised immune systems, the highest level of purity offered by distilled water can be a benefit by reducing the risk of waterborne pathogens. Concerns about fluoride removal and dental health are also worth noting for both types of water, though the impact is lessened with regular dental hygiene. For further reading on safe drinking water, consult the CDC guidelines on water treatment.

Conclusion

Ultimately, there is no single right answer to the question, "is distilled water better or purified?". The best choice is entirely dependent on its purpose. For everyday drinking and cooking, purified water offers a balance of safety and taste, retaining some healthy minerals. For specialized applications requiring the highest level of purity, such as medical equipment or scientific labs, distilled water is the necessary standard. Both are excellent choices compared to unfiltered tap water, and understanding their key differences empowers you to make the most informed decision for your needs.

Frequently Asked Questions

Yes, distilled water is safe to drink daily, provided you have a balanced diet that provides essential minerals like calcium and magnesium, which are removed during the distillation process.

Purified water generally tastes better to most people because it often retains some minerals that contribute to flavor. The absence of minerals gives distilled water a flat, bland taste.

Distilled water is often recommended for baby formula due to its exceptional purity, ensuring no contaminants are introduced to a developing immune system. However, purified water is also considered safe, and you should always consult a pediatrician for guidance.

Distilled water is best for appliances like coffee makers and humidifiers because it prevents mineral buildup (scale) that can clog and damage the machine over time. This extends the lifespan of the equipment.

Distilled water is the standard in laboratories and medical facilities. Its ultra-high purity ensures that no minerals or contaminants interfere with scientific experiments or sterile medical procedures.

Effective purification methods, like reverse osmosis and UV sterilization, are designed to remove bacteria and viruses, making purified water a very safe drinking option.

No, purified water is held to a higher standard. While filtered water passes through a filter, purified water must have contaminants removed to a specific level (TDS <10 ppm) using processes like reverse osmosis, distillation, or deionization.

Distilled water is too pure for aquariums and can be harmful to fish. The lack of minerals can cause massive and dangerous pH swings, and fish require certain minerals like calcium and magnesium for osmoregulation.