What is the Purest Bottled Water to Drink?

January 12, 2026 •

4 min read

According to the Environmental Working Group, a significant percentage of bottled water is simply tap water that has been put through a purification process. The quest to find the purest bottled water to drink involves navigating various types, from naturally sourced spring water to highly filtered options like distilled or reverse osmosis water.

Quick Summary

This guide examines the different types of bottled water, the purification methods they undergo, and the criteria that define purity. It compares leading brands and provides insight into which bottled water is genuinely the cleanest option for consumers.

Key Points

Purified Water with RO is Chemically Purest: Water purified by Reverse Osmosis (RO) has a very low Total Dissolved Solids (TDS) count, making it one of the purest options for drinking.
Distilled Water is Not for Drinking: While technically the most pure with a TDS of 0 ppm, distilled water lacks beneficial minerals and has a flat taste, making it unsuitable for regular consumption.
Spring Water Purity Varies: Spring and mineral waters contain naturally occurring minerals, and their purity depends on the specific source, with varying levels of TDS.
Purification Method is Key: The most rigorous bottled water purification methods involve multiple steps, including carbon filtration, UV treatment, and reverse osmosis.
Bottled vs. Tap Water Regulations: In many regions, tap water is more strictly regulated by government agencies than bottled water, and testing shows many brands are sourced from municipal supplies.
Consider Environmental Impact: The purest option for health is not always the purest for the environment; consider a home filter and reusable bottle for a sustainable solution.

The search for the purest bottled water to drink is a common one, driven by a desire for clean, healthy hydration. The term 'pure' can be misleading, as it can refer to the absence of contaminants, the presence of beneficial minerals, or a combination of both. Understanding the purification methods and sourcing behind different types of bottled water is essential to making an informed choice.

The Definition of Pure Water

When evaluating bottled water, purity is measured in several ways. The most stringent definition of pure water is based on its Total Dissolved Solids (TDS) level, which measures the concentration of all inorganic and organic substances. Lower TDS generally indicates higher chemical purity.

Distilled Water: Achieved by boiling and re-condensing water, leaving all minerals and contaminants behind, resulting in 0 ppm TDS. It's chemically pure but lacks flavor and isn't typically for drinking.
Reverse Osmosis (RO) Water: Processed through a semi-permeable membrane to remove impurities and dissolved solids, resulting in very low TDS (typically 1-10 ppm). Brands like Aquafina and Dasani use this method, sometimes adding electrolytes back for taste.
Deionized (DI) Water: Uses ion-exchange resins to remove charged ions. Often paired with RO for ultra-pure water, primarily for industrial or laboratory use, not drinking.

How Do Natural Waters Measure Up?

Natural waters are valued for their mineral content but vary in contaminant removal compared to highly filtered options.

Spring Water: Sourced from an underground formation flowing to the surface. Naturally filtered but contains minerals, leading to variable TDS. May undergo additional filtering or UV treatment for safety.
Mineral Water: From an underground source with a stable mineral composition that cannot be altered. Brands like Evian have higher TDS and distinct tastes due to minerals.

Purification Methods and Their Effects

Bottled water companies employ various methods to achieve desired purity levels.

Filtration: Removes larger particles but doesn't achieve chemical purity.
Ultraviolet (UV) Treatment: Disinfects water by inactivating microorganisms with UV light.
Ozonation: Uses ozone gas to disinfect water and kill microorganisms.
Remineralization: Minerals are added back to highly filtered water (like RO) to improve taste and provide electrolytes.

Comparison of Popular Bottled Water Types

Choosing the right bottled water requires understanding the differences. The table below compares common types:


Feature	Distilled Water	Purified (RO) Water	Spring Water	Mineral Water
Source	Any source	Any source	Underground spring	Underground source
Purification Method	Boiling, then condensation	RO, deionization, filtration	Natural filtration, potential UV/micron filtering	Minimal processing to preserve mineral content
TDS Level	Near 0 ppm	Very low (e.g., 1-25 ppm)	Varies widely	Varies, can be high
Taste Profile	Flat	Clean, crisp	Smooth, depends on minerals	Distinctive, strong flavor
Health Benefits	Hydration only; potential mineral leaching	Hydration, potentially supplemented electrolytes	Hydration, plus natural minerals and electrolytes	Hydration and potential mineral benefits
Best For	Appliances	Daily drinking, pure taste seekers	Daily drinking, mineral seekers	Those who prefer mineral-rich water

The Verdict: So What is the Purest Bottled Water?

If purity is defined strictly by the absence of dissolved solids, distilled water is technically the purest bottled water. However, its lack of minerals and flat taste make it less desirable for daily drinking. For most consumers seeking clean water, purified water using multi-step filtration like reverse osmosis is a better choice. Brands such as Aquafina utilize rigorous purification from municipal sources to achieve a low TDS. While spring and mineral waters offer beneficial minerals, their overall contaminant removal may not match highly filtered options.

The Bottom Line for Consumers

Your choice depends on your definition of purity and taste preferences. For minimal dissolved solids and maximum contaminant removal, reverse osmosis purified water is ideal. If you value taste and natural minerals, a reputable spring or mineral water is suitable. Both tap water (often highly regulated) and bottled water are generally safe, but advanced filtration in bottled water can offer a higher purity level.

Conclusion

Determining the purest bottled water hinges on your priorities. For the lowest dissolved solids, purified RO water is recommended for daily consumption. Distilled water, while chemically purest, lacks minerals and is not ideal for drinking. Spring water suits those who prefer natural minerals and taste. Always check labels for source and purification methods. For guaranteed high purity and clean taste, multi-stage reverse osmosis is a reliable option.

The Environmental Factor

Bottled water's environmental impact is considerable due to plastic production and transport. Reusable bottles and home filtration systems (like RO) are more sustainable and can provide pure water long-term. Consider a home water filtration system for a greener approach to hydration while maintaining purity.

For more information on reducing environmental impact, visit the EPA's website on sustainable water use.

Frequently Asked Questions

The main difference is the source and purification method. Purified water, like reverse osmosis (RO), comes from any source and is treated to remove contaminants and dissolved solids. Spring water comes from a natural, underground source and contains natural minerals, which means its purity and TDS can vary.

Yes, distilled water is safe to drink occasionally, but it is not recommended for regular, long-term consumption. Because it lacks minerals, some believe it can leach minerals from the body over time. It is often used for small appliances to prevent mineral buildup.

Yes, studies have shown that most bottled water contains microplastic particles, which can leach from the plastic packaging itself. Choosing reusable glass or stainless steel bottles is a good way to avoid this.

Look for a Total Dissolved Solids (TDS) level on the bottle or company website. A lower TDS indicates higher purity. Some bottled water companies also publish water quality reports, as recommended by organizations like the Environmental Working Group (EWG).

The answer varies depending on the specific water source and purification methods. Many bottled waters are simply purified municipal tap water. In many countries, tap water is subject to stricter government regulation than bottled water, but advanced home filtration systems can improve tap water quality even further.

Reverse osmosis removes a broad range of contaminants, including dissolved salts, particles, organic matter, and heavy metals. It forces water through a semi-permeable membrane, leaving impurities behind and producing a very pure product.

It depends on your health goals. Mineral water provides natural minerals and electrolytes, which some people value for taste and potential health benefits. Purified water, with fewer or no dissolved solids, is ideal if you want water with minimal mineral content.