Take a mouthful of water, letting it linger initially on the tongue before swilling it around the mouth. Hold the water over the back of the tongue before swallowing. This technique allows you to assess acidity, sapidity, structure, lightness and mouth feel.
To assess the balance and length of finish of the water, take a second mouthful and let it lie on the tongue. Breathe in a small amount of air through the mouth and breathe out through the nose.
Continue as before, holding the water over the back of the tongue and then swallowing.