What Boiling Water Does
Boiling water is one way we make water safe to drink. It kills most bacteria and destroys most organisms present. Boiling does not remove dirt, minerals or some compounds from water, however. For that, we must "purify" water---that is, separate the water from impurities in it. Distilled water, by definition, contains dihydrous oxide and nothing else. Since water is the standard for a neutral pH, its pH is 7.0. So, no. Although water that is boiled for a few minutes is reliably safe to drink, it is not distilled. Boiling water is, however, the first step to distillation.
Ways to Purify Water
Distillation, filtration and reverse osmosis are methods of purifying water. They remove dirt, minerals and other impurities that may make water "hard" or undrinkable. Filtration and reverse osmosis involve moving water through barriers that remove impurities. They are used for city water supplies and drinking water, applications in which it is important to have clean, safe water to drink. Deionization is used in most home water softeners to remove certain minerals, like calcium and iron, from water. Distillation, the oldest method of purifying water, actually removes the water from the impurities. Distilled water is as mineral-free and neutrally charged as possible. Only distillation removes all organic and non-organic impurities. Since production is more exacting, its use is limited to laboratory applications or any place (like an iron or humidifier) in which completely pure, neutral water is necessary.
Unlike other methods of water purification, distillation actually changes the state of water. The temperature at which any compound changes states differs from that of other compounds. Water can be turned into a gas or vapor at a fairly low temperature. It is then literally "boiled away" from impurities by allowing the vapor to escape the boiling chamber. The vapor is routed away from the boiling pot through a long, thin passageway, leaving everything else in the chamber. As it travels along this passage, it cools and condenses until it drips into a receptacle set to catch the purified liquid at the other end. Re-doing the process yields "double-distilled" water. The drawback to this seemingly superior method is that the operator must clean the equipment carefully after each use and keep surfaces absolutely sterile to avoid adding impurities during the process. Although it may seem logical that distilled water would be safer to drink than any other water, the benefits or dangers of using distilled water for consumption are hotly debated. Those who argue for it claim that it is the safest form of water. Those who argue against insist that distilled water robs the body of trace elements and minerals that occur naturally in clean water.