Defining 'Pure': A Scientific and Consumer Perspective
The idea of what constitutes 'pure' water can vary greatly. From a scientific standpoint, pure water (H2O) contains no dissolved solids, minerals, or other compounds. Distillation, where water is boiled and the steam is collected, is one of the most effective methods for achieving this level of purity. In contrast, a consumer might define purity by the water's source, preferring naturally filtered spring or artesian water from pristine, protected environments.
The Purest by Scientific Standards: Distilled Water
Distilled water is created by boiling water into vapor and then condensing the steam back into liquid, leaving behind minerals and contaminants. This process results in a product with a Total Dissolved Solids (TDS) reading of near zero, making it chemically the purest form of bottled water available. While it is excellent for scientific or industrial applications where mineral content is a concern, it lacks the beneficial electrolytes and minerals found in natural waters, which some people prefer for taste and health reasons.
The Purest from a Natural Source: Artesian and Glacial Water
Some of the world's most prized bottled waters come from exceptionally protected and remote natural sources. These waters often have a naturally low mineral content because they have been filtered through ancient geological formations, such as lava rock or deep limestone aquifers, for thousands of years. A brand like Hallstein Water, sourced from a deep aquifer in the Austrian Alps, is noted for its low nitrate level and natural filtration. Similarly, Icelandic Glacial water comes from Iceland's Ölfus Spring, where it's filtered through lava fields. These natural filtering processes create water with a unique, clean taste and high-level purity.
Purified Water: Processed for Purity
Many common bottled water brands labeled as "purified" undergo extensive treatment processes, often starting from a municipal water source. These processes can include reverse osmosis, deionization, and absolute 1 micron filtration to remove impurities. Reverse osmosis (RO) is a popular method where water is forced through a semipermeable membrane that removes minerals and contaminants. Some brands then reintroduce a proprietary blend of minerals for taste. While highly clean, some critics argue this method doesn't capture the essence of natural water.
Comparing Different Types of Bottled Water
To make an informed decision, it's helpful to compare the characteristics of different bottled water types. Here is a comparison of some key factors:
| Feature | Distilled Water | Natural Spring/Artesian | Purified (RO/Deionized) |
|---|---|---|---|
| Source | Municipal water source | Protected underground spring or aquifer | Municipal or other source |
| Purity Level | Very high (near zero TDS) | Naturally low TDS, but varies by source | Very high (typically low TDS) |
| Mineral Content | Essentially none | Varies; naturally occurring minerals present | None initially; sometimes added back for taste |
| Processing | Boiling and condensation | Minimal treatment (disinfection) to maintain integrity | Extensive filtration (RO, UV) and sometimes remineralization |
| Taste Profile | Flat, lacking flavor | Unique taste reflective of mineral content | Can be flat or remineralized for flavor |
| Health Factors | May not provide beneficial minerals | Provides naturally occurring minerals | Can be fortified with added minerals |
Factors Influencing the Definition of Purity
Beyond the base TDS level, other factors contribute to the perceived purity of bottled water. Sustainable sourcing, packaging, and the absence of contaminants like microplastics and PFAS are increasingly important to consumers. The FDA regulates bottled water quality, but voluntary certifications, such as those from the National Sanitation Foundation (NSF), provide additional assurance that companies meet strict standards beyond the federal requirements.
The Role of Packaging
The container itself can impact water's purity. Traditional plastic bottles can leach chemicals into the water over time, though reputable brands use BPA-free PET plastic. Alternatives include glass, aluminum, or plant-based cartons, which many consider safer and more eco-friendly. For instance, brands like JUST Water use plant-based cartons, emphasizing both purity and sustainability.
The Debate Over Minerals
One of the main points of contention is whether pure water should contain minerals. While some seek the complete absence of dissolved solids, others prefer the taste and potential health benefits of naturally mineral-rich water. Mineral water, by FDA definition, must have at least 250 parts per million (ppm) of naturally occurring dissolved solids. This richness is often what gives these waters their distinct flavor profile. So, while scientifically less pure, they are naturally complete and may be preferred for daily hydration. For further reading on water quality and regulations, the Food and Drug Administration website offers extensive information.
How to Choose the Purest Water for You
With various options, finding the "purest" bottled water is a personal choice. Consider what attributes matter most to you. If your goal is to consume water with zero dissolved solids, a distilled or highly purified water is the best choice. If you value a natural, unprocessed product from a protected source, a low-TDS spring or artesian water might be ideal. Always read labels to understand the source, processing, and mineral content. Checking for third-party certifications can provide extra peace of mind. Your definition of purity, whether scientific, natural, or a blend of both, will guide you to the right bottled water for your needs.
