Distilled water is made by boiling water and collecting the steam, which leaves behind virtually all minerals, chemicals, and contaminants. Bottled water is a broad category that includes spring water, mineral water, and purified water, each with different sources and processing methods. The core difference comes down to mineral content: distilled water contains almost nothing besides water molecules, while most bottled water retains or adds minerals that affect taste, pH, and nutritional value.
How Each Type Is Produced
Distillation is a straightforward physical process. Water is heated to boiling, the steam rises and is captured, then it cools back into liquid form. Because minerals, heavy metals, bacteria, and most dissolved solids can’t evaporate with the steam, they get left behind. The result is water that’s had roughly 99.9% of its dissolved materials removed.
Bottled water production depends entirely on the type. Spring water is collected from an underground source where water flows naturally to the surface. The FDA requires that the spring’s location be identified and that the water maintain the same composition it had underground. It may or may not be treated after collection. Purified bottled water, on the other hand, goes through a multi-step industrial process: chemicals are added to bind with particles, those clumps settle to the bottom, then the clean water passes through sand, charcoal, and gravel filters to remove bacteria, viruses, dust, and chemicals. A final disinfection step uses chlorine or similar agents to kill anything that survived. Mineral water must come from a protected underground source and contain at least 250 mg/L of total dissolved solids.
What’s Actually in the Water
Distilled water is as close to pure H₂O as you can practically get. Its total dissolved solids are near zero. That means no calcium, magnesium, sodium, fluoride, or any of the trace minerals found in most drinking water.
Bottled spring and mineral water contain varying amounts of these dissolved minerals depending on their geological source. Still bottled water typically has a pH between 6.9 and 7.5, and mineral water sits between 7.1 and 7.5. Distilled water, by contrast, has a pH of about 5.7, making it slightly acidic. That lower pH happens because distilled water absorbs carbon dioxide from the air once exposed, forming a weak acid. This isn’t dangerous to drink, but it does affect taste and makes distilled water mildly corrosive to certain metals over time.
Taste Differences
Most people describe distilled water as flat or bland. That’s because the minerals in water are what give it a sense of body and flavor. Calcium adds a slightly chalky quality, magnesium can taste faintly bitter, and the overall mineral profile creates what people perceive as “crispness” in spring or mineral water. Without any of those dissolved solids, distilled water tastes noticeably empty. Some people find it unpleasant. Others don’t mind, but the difference is real enough that you’d likely notice it in a side-by-side comparison.
Health Considerations
Drinking distilled water occasionally is perfectly fine. The concern is with long-term exclusive use. Water provides a meaningful portion of your daily intake of essential minerals, particularly calcium and magnesium. When you remove those minerals entirely, you lose that dietary contribution, and the effects compound over time.
There’s another issue that surprises most people: cooking with demineralized water pulls minerals out of food. Research published in the Medical Journal of the Armed Forces India found that using demineralized water for cooking can leach up to 60% of the magnesium and calcium from vegetables, meat, and cereals. Losses for other trace elements were even higher: 66% for copper, 70% for manganese, and 86% for cobalt. So it’s not just about what’s in the water you drink. It’s also about what the water takes out of your food.
Studies have linked long-term consumption of water low in calcium to higher fracture risk in children, and water low in magnesium to increased risk of pregnancy complications like preeclampsia. These findings don’t mean a glass of distilled water is harmful. They mean that relying on it as your only water source, especially for cooking, creates a slow mineral deficit that adds up.
Bottled spring and mineral water don’t carry these concerns. They retain naturally occurring minerals, and mineral water in particular can be a supplementary source of calcium and magnesium, depending on the brand and source.
What Distillation Removes (and Doesn’t)
Distillation is highly effective at removing heavy metals, dissolved solids, most bacteria, viruses, and inorganic contaminants like nitrate, sodium, fluoride, and sulfate. For people dealing with contaminated well water or poor municipal supply, distillation offers a reliable level of purification.
It does have a blind spot, though. Volatile organic compounds, the chemical pollutants that evaporate at temperatures close to water’s boiling point, can travel with the steam and end up in the “purified” water on the other side. If your water source contains these compounds (common near industrial or agricultural areas), distillation alone won’t fully remove them. A carbon filter before or after distillation handles this gap.
Standard bottled water filtration addresses a different set of concerns. The multi-stage process of coagulation, sedimentation, and charcoal filtration is designed for large-scale municipal-style treatment, removing particulates, bacteria, and chemical disinfectant byproducts. Reverse osmosis, used by some bottled water brands, removes dissolved solids similarly to distillation but often adds minerals back afterward for taste.
When Distilled Water Is the Better Choice
Distilled water is preferred or required for specific equipment and appliances. CPAP machines used for sleep apnea are the most common example. Manufacturers and sleep medicine experts recommend distilled water because the humidifier chamber aerosolizes the water directly into your airway. Your lungs lack the acid defenses your stomach has, so any bacteria or minerals in the water can cause irritation or infection. Even purified bottled water can leave trace mineral deposits that degrade CPAP components over time.
The same logic applies to steam irons, certain humidifiers, car batteries, and laboratory equipment. Minerals in regular bottled water create scale buildup that clogs small openings and reduces performance. Boiling tap water kills microorganisms but doesn’t remove dissolved minerals, so it’s not a substitute for distilled water in these applications.
Cost and Availability
Distilled water is widely available at grocery stores and pharmacies, usually sold in gallon jugs for a dollar or two. It’s marketed primarily for appliance use, though nothing stops you from drinking it. Bottled spring and mineral water come in a wider range of sizes and brands, with prices varying dramatically based on source and branding. For daily drinking, bottled spring or mineral water offers better taste and nutritional value. For equipment that needs mineral-free water, distilled is the only appropriate option.
If you’re choosing between the two purely for hydration, bottled water with its natural mineral content is the better everyday choice. Distilled water serves a specific purpose, and it does that job extremely well, but it wasn’t designed to be your primary drinking water.