Champagne glasses are made tall to indicate that the drink that goes in the glass should be cold. The stem that adds to the height of the champagne glass helps you get a better flavor without your body heat from your fingers changing the taste and aromatics of the drink.
The wider bowl is beneficial as it allows a little more room for aeration of the wine, and therefore allows greater development of flavours and aromatics. The narrowing towards the rim also captures and preserves the aromas in the glass and focuses them more towards the nose, to inhale deliciously with every sip
Bubbly poured into a long narrow flute provides more of a nose-tingle than when served in a wide and shallow ‘coupe’, thanks to high levels of carbon dioxide at the top of the glass.