Soda and Sparkling Drink Guides: Fizz, Flavour and Storage

Carbon dioxide dissolves into cold liquid under pressure and comes out of it as the pressure drops or the temperature rises. That is why a warm bottle fizzes over, why an opened one goes flat, and why ice poured into soda makes it foam.

Flavour in this family is mostly a balance of sweetness, acidity, and bitterness, and carbonation itself contributes a mild sharpness of its own through the carbonic acid it forms.

Cold is what holds the gas. Carbon dioxide dissolves far better in cold liquid than warm, so a bottle chilled before opening keeps its carbonation and one opened warm gives most of it up at once.

How you pour decides how much survives the glass. Down a tilted side keeps the bubbles in the drink; straight into the bottom drives them into a head that collapses.

The names on this shelf describe ingredients rather than strength. Seltzer is defined by an absence, soda water by added salts, and tonic by quinine and a great deal of sugar.

Bitterness here is deliberate and rare.

Tonic is the one mainstream soft drink built to be bitter, and it is also far sweeter than most people expect it to be.

Sweetener choice changes the aftertaste more than the sweetness. Cane sugar, high fructose syrup, stevia and sucralose each leave a different finish behind the same flavour.