Expert: Ralph Salier-Hellendag - 11/4/2009

Question
I need to explain natural carbonation of soda to a 10 year old.  Could you please help?  Thanks!

Answer
Hi Kimberly,

Soda like Coke, Pepsi etc... are artificially carbonated.  This is done by injecting CO2 (Carbon Dioxide Gas) into the drink just prior to sealing the container under pressure which keeps the CO2 dissolved in the drink.  Once opened, then the CO2 can come out of solution in the form of bubbles or "Fizz".  Depending on the quality of the water, the amount of sugar (or artificial sweetener) more or less CO2 can be injected into the soda.  The formula is a carefully guarded secrete since it impacts the taste and sale-ability of the soda in a given region.  You may not be old enough to remember soda fountains at the lunch counter but what they did was to mix the syrup with soda water (like seltzer water) to provide the fizz to the water and syrup mixture.  The soda water was kept under pressure in a keg under the counter.

You can find Natural Carbonation is drinks like Beer, Sparkling Wines and Champagne.   These naturally carbonated drinks get that way through a process called fermentation.  In these drinks, yeast is added along with sugar and some times ammonium nitrate (a yeast food) that causes the yeast to eat the sugars and convert them into alcohol and CO2.  In low sugar environments ammonium nitrate is used so no sugar is added but will still make CO2 as in dry wines.  As these are processed, and CO2 is being formed, these are pumped into pressurized storage tanks just prior to filling the bottles (cans or kegs for beer) and then quickly sealed to retain the CO2.  The CO2 also acts as a preservative.


en.wikipedia.org/wiki/Fermentation -

www.encyclopedia.com/topic/fermentation.aspx

Here are two websites  that may help you explain this to your child.

If this is still to complex, let me know and I will try to come up with perhaps a novel way to show it to your child.