The pH (for "potential hydrogen") measures a substance's level of acidity or alkalinity. On this scale, 1.0 to 6.9 is acidic, 7.0 is neutral, and 7.1 to 14.0 is alkaline. Sour tastes, such as vinegar, come from acids, whereas alkaline substances tend to taste bitter and seem to have a slippery, soapy feel. Low-alkaline waters (pH levels of 7.1 to 7.5) may be perceived as sweet — this doesn't mean that the water tastes sugary but simply that it tastes neither bitter nor sour. Since pH is a logarithmic scale, the difference of 1 degree indicates a tenfold increase or decrease in acidity or alkalinity. Water with a pH of 5, for example, is 10 times more acidic than water with a pH of 6. My palate tends to register acidity as a significant component of taste at a pH of 6 or below. Alkalinity becomes a factor in the taste and mouthfeel for me at a pH of 8 or higher. The following is how I describe Orientation, which is the taste of water based on the pH factor, as you'll see in my tasting notes:
Distillation, reverse osmosis, and ion exchange can remove nitrate from water. Several manufacturers offer equipment to apply these techniques to home drinking water. Nitrate isn't removed by standard water softeners or filters, including carbon adsorption filters, and boiling water increases nitrate concentration.
Great water often has to come from remote sources, and remote sources are by definition hard to get to. Building a bottling plant in remote areas, together with the problematic transportation makes water from remote regions more expensive. The virginality concept allows consumers to appreciate the effort made by bottlers to source uncompromised waters and bring them to the table.