Not Just Convenient
It takes a minute or two to make whipped cream in a powerful stand mixer, and it can take three to five if you're whisking it by hand. The heavy cream and bowl must be well chilled for the best results, and even then the cream only holds its shape and airiness for an hour or two at room temperature. In contrast, whipped cream from an aerosol canister or refillable "charger" is fully whipped when it comes from the can's nozzle. Aside from its speed and convenience, aerosol whipping produces the lightest, longest-lasting whipped cream – and you can pick up these whipped cream canisters from any grocery store or convenience store – or even Amazon!
How It Works
Despite the apparent contradiction, cream's heavy fat content is what makes it light and fluffy when it's whipped. Ordinarily, that fat takes the form of tight globules, held together by strong molecular bonds. The wires of your whisk shear those bonds and incorporate air, so when the fat molecules re-connect, they surround a small pocket of that air. The longer you whip, the lighter the cream gets, and the more air it traps. Aerosol cans like Reddi-Wip or Whippits replicate that effect instantly by using a compressed gas as a propellant, usually nitrous oxide, to force the cream through a tiny nozzle.Contrary to popular belief, carbon dioxide is not used! The fat globules are sheared and inflated in a split second, creating a perfectly fine and uniform foam.
The Good and The Bad
The silky, perfect whipped cream from your aerosol can or whipped cream charger has the advantages of speed and durability, but that doesn't mean you should hang up your whisk. Canned cream often lacks the fresh flavor of cream you've whisked by hand, and you give up the option of sweetening it to your own taste or using superior vanilla as the flavoring. The nozzles on the cans of whipped cream re-create the star tip on a pastry bag, but for garnishing desserts, the pastry bag gives much better control along with a wide range of tips to create special decorations. All in all, making your own is often the better option.
The Ugly
Nitrous oxide is used in the aerosol cans and refillable chargers because it's an inert gas that prevents the cream from spoiling and because it quickly dissipates once it's sprayed. Unfortunately, nitrous oxide is the "laughing gas" long used as an anesthetic by dentists, and it's frequently used as an inhalant recreational drug. Like other inhalants, nitrous oxide can be extremely dangerous for its euphoric effect, and it's sometimes fatal even to first-time users. Nitrous oxide abuse is most common among minors and young people, as whipped cream dispensers and other devices with nitrous oxide are easy to purchase. There are side effects to be aware of, so be sure to contact substance abuse and mental health services if you or someone you know is having these problems.