What Is Alkaline Water?
Alkaline water is water with a pH above 7. That's the short answer. The longer answer involves understanding what pH means, why some water is more alkaline than others, and what the research actually says about whether drinking it does anything useful.
The pH Scale: 0 to 14
pH measures how acidic or alkaline a solution is on a scale of 0 to 14. Pure water sits at exactly 7, neutral. Anything below 7 is acidic. Anything above 7 is alkaline. Stomach acid runs around pH 1.5 to 2. Lemon juice is around pH 2. Baking soda is pH 9. Bleach is pH 12.
Most tap water falls between pH 6.5 and 8.5. Most bottled water sits in the same range. Alkaline water is typically marketed at pH 8 to 10, though some products like QURE go higher.
The pH level of alkaline water comes from minerals: calcium, magnesium, potassium, and bicarbonates, either naturally occurring in the water source or added during processing. Some alkaline water is produced through electrolysis, where an ionizer uses electrical current to separate water into acidic and alkaline streams. Hydrogen ions are removed in the process, raising the pH.
What the Research Says
The health claims around alkaline water run ahead of the evidence. That's not unusual for water marketing. Here's what the studies have actually found.
Acid Reflux and pH 8.8
Koufman and Johnston (2012, Annals of Otology, Rhinology & Laryngology) found that alkaline water at pH 8.8 permanently inactivated pepsin, the digestive enzyme most associated with acid reflux damage. In lab conditions, alkaline water could neutralize pepsin more effectively than regular water. This is one of the more credible findings in alkaline water research. It has a plausible mechanism, and the study used verified methodology.
The important caveat: this was a lab study, not a clinical trial. Whether drinking alkaline water meaningfully reduces acid reflux symptoms in people is not established by this study. Alkaline water might help. It might not.
Hydration After Exercise
Chycki et al. (2017, Journal of the International Society of Sports Nutrition) found that alkaline water improved hydration markers in athletes compared to regular water after intense exercise. The study was small (28 participants) but showed measurable differences in blood viscosity and acid-base balance.
The implication: alkaline water may offer a hydration edge in high-intensity athletic contexts. For most people (walking, desk work, casual exercise) there's no evidence alkaline water hydrates better than tap water.
What Alkaline Water Probably Can't Do
Claims about alkaline water and cancer, bone density, aging, and immune function are not supported by credible evidence. The body tightly regulates blood pH regardless of what you drink. Drinking alkaline water does not meaningfully change blood pH. The kidneys and lungs handle that. The idea that you can "alkalize your body" by drinking alkaline water isn't how human physiology works.
That said, alkaline water isn't harmful for most people. If you find you drink more water because you prefer the taste, that's a real benefit. Hydration matters.
Alkaline Water Brands and Their pH Values
Here's what you actually get in major alkaline water brands:
- Essentia Water: pH 9.5+. Ionized, with added electrolytes. One of the best-known alkaline water brands. Most widely available in convenience stores and gyms.
- Waiakea Hawaiian Volcanic Water: pH 8.8. Naturally alkaline from volcanic rock filtration. No ionization needed. Good mineral profile with calcium and magnesium.
- Alkaline88: pH 8.8. Uses Eighty-Eight Water's proprietary process. Widely available at Walmart and Target.
- QURE Water: pH 10. One of the highest-pH alkaline waters on the market. Ionized. Strong alkaline taste some people notice.
- Core Hydration: pH 7.4. Technically just above neutral. Markets as "perfect pH" matching the body's pH. Not strongly alkaline, but positioned in the alkaline water category.
- Evian Natural Spring Water: pH 7.2. Not alkaline water by most definitions, but has a clean mineral profile with calcium and magnesium.
For most people shopping for alkaline water, Essentia and Waiakea are the straightforward options. Essentia is the most consistent in pH and availability. Waiakea gets its pH naturally rather than through ionization, which some buyers prefer.
Alkaline Water vs. Regular Water
Regular water (tap water, most still bottled water) is neutral or slightly acidic to slightly alkaline (pH 6.5 to 8). There's nothing wrong with it. The idea that regular water is too acidic for your body isn't supported by evidence.
If you drink tap water and feel fine, you don't need alkaline water. If you're a high-performance athlete looking for marginal hydration advantages, the limited evidence suggests alkaline water might help. If you have acid reflux, alkaline water at pH 8.8 has some biological plausibility for symptom management. Consult a doctor.
The most honest summary: alkaline water is probably not harmful, the benefits are modest and context-dependent, and the marketing is significantly ahead of the science.
How to Drink Alkaline Water
There's no established protocol for drinking alkaline water. People who drink it regularly typically use it as their primary water source: with meals, during exercise, and throughout the day.
A few things worth knowing when you drink alkaline water:
- Drinking alkaline water with meals may reduce its potential acid-buffering effect in the stomach. Stomach acid is there to digest food. You probablybably don't want to neutralize it.
- The minerals in alkaline water (calcium, potassium, magnesium) can contribute to daily mineral intake, though the amounts are small.
- High-pH alkaline water (above pH 9) has a slightly different taste that some people prefer and others find off-putting.
CustomWater.com and pH
CustomWater.com produces custom labeled bottled water using standard still water at neutral pH. We don't produce alkaline water. If you're looking for alkaline water for events or branding, we can discuss options. request a quote to talk through what's possible.
For more on related topics: how to make alkaline water at home covers DIY methods and ionizer options. best alkaline water brands goes deeper on the top products and what to look for.