The science behind soda water

We all love to have a sip of our favourite soft drink when we are thirsty, especially in summers. And we also love to have a little fizz in it. This fizz is the bubbly effervescence that is produced by adding pressurized carbon dioxide gas to water. It’s also called carbonated water or just soda water.

The first soda
Joseph Priestley was the first person to invent soda water. He suspended a bowl of water over a beer vat in a brewery and patiently waited to see what happened. Soon the bowl of water was fizzing with carbon dioxide released from the fermentation of beer. And that was how soda was born. However, it was only in the later part of the 19th century that soda water was introduced as a popular soft drink.

Flavoured soda drinks
Eugene Roussel, a Frenchman in Philadelphia, was the first person to popularize flavoured soda soft drinks. He set up a small counter in the perfume shop that he owned and offered customers glasses of orange, cherry, lemon, teaberry, ginger, peach and root beer flavoured soda water. And since the people who started producing soda water were chemists, this product was easily available in medical shops in the United States.

The chemistry of soda
When carbon dioxide is mixed in water it forms carbonic acid. To this, salts like sodium bicarbonate (food grade, the CAS number is 144-55-8) are added to reduce the amount of acidity in the drink. Sodium and other metallic salts are used to neutralise the acidic flavour of the drinks.

Today, soda water is made by sending pressurized carbon dioxide through water. The high pressure allows more carbon dioxide to dissolve than it would normally be possible. The soda is then packed into an airtight bottle. When this pressurized bottle is opened, the gas rises to the top bubbling. And if you shake the bottle before opening, the soda will spill out splashing all over, when opened.