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Fizzy drinks leave sour taste in the mouth

soft drink can

The research helps explain why a fizzy drink will never taste the same as a flat drink with the same base ingredients (Source: stock.xchg)


In an article published in the journal Science, the researchers speculate that the ability to taste carbonation may have evolved as a reaction to help humans avoid foods that are going off and have begun fermenting.

They claim that sour and bitter tastes often indicate foods that should be avoided, while sweet, salty, and the savoury taste sensation called umami, are those that can be beneficial.

The research follows recent work showing that fruit flies can taste carbon.

Unlike humans, fruit flies sense the taste of carbon dioxide as an encouragement, indicating the presence of growing microorganisms.

Drink design

The latest research, led by Dr Jayaram Chandrashekar of the University of California, San Diego was done using genetically engineered mice.

Sensory scientist Dr Hannah Williams of Curtin University of Technology in Perth says the research is likely to help drink manufacturers to better manipulate the flavour of new products.

"It's about the understanding of how carbonation affects flavour perception," she says. "The application of it is in understanding where your flavours are coming from."

"Often when you're creating a beverage, you produce the base liquid without a lot of carbonation in it and you do a lot of sensory testing on that. It's going to change when you carbonate it, because of that sour note."

But it's not only the sour taste of carbon that we perceive when drinking 'fizzy' drinks, a whole range of senses are stimulated by the physical sensation of swigging the bubbles created by carbonation.


The bubbles also trigger nerves in the mouth to create, what Williams calls, the "fizz factor".

This means that a fizzy drink will never taste the same as a flat drink, even if they have the same base ingredients.

Williams, who researches the taste of wine, says that it may explain the sour taste of champagne.

"One of the things you often hear when people first start drinking champagne is that it's sour compared to other wines," she says.

"It does have a different note and I guess it comes from the carbonation effect."
