The propellant used in whipped cream is the same chemical compound that dentists use to make you laugh during a procedure. Nitrous oxide, also known as laughing gas or rocket fuel, has been in use for more than a century. This invisible gas is a sweet-tasting, weak anesthetic that doubles as a foaming agent when you press down on the nozzle of a whipped cream can. But the luxurious, airy cream doesn't last for long, so eat it quickly.
Manufacturers add nitrous oxide to the liquid cream once it enters the can. Since the nitrous oxide is fat soluble and easily dissolves in the liquid cream, it is possible to fill the can with high amounts of gas using a low-pressure system. Depressing the nozzle on the can releases the pressure inside little by little, filling the freed liquid cream with airy bubbles as the gas escapes the solution. The foaming action ceases as the nitrous oxide totals in the can diminish.
Unlike fresh whipped cream, which relies on a network of airy bubbles beaten into a liquid base to create its stable structure, aerosol whipped cream is completely unstable. The bubbles created by the nitrous oxide pumped into the liquid cream inside the aerosol container tend to lose form quickly -- within approximately 30 minutes in most cases. Once collapsed, what was once a foamy cream becomes nothing more than a shiny, shapeless liquid.
An Airy Difference
Nitrous oxide is the obvious choice for fueling the froth released from whipped cream cans. Unlike air, which when pumped into liquid cream only produces a foam twice the size of the contents of the can, nitrous oxide produces creamy foam four times the contents of the can. Pumping air into the can would also cause the liquid cream to turn rancid, compromising the quality and safety of the product. Like air, a carbon dioxide propellant would affect quality by curdling the cream.
Nitrous oxide is non-flammable and deemed safe for use in foods by the U.S. Food and Drug Administration. Recognized as safe when used as a whipped cream propellant, nitrous oxide also has a history of recreational use. Chronic abuse, via the inhalation of the propellant, can have dangerous consequences. Short-term exposure to the gas leads to mental impairment and dexterity problems. Long-term exposure often results in reproductive problems, neurological disorders and suffocation.
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