So, whipped cream is basically just cream that’s been whipped until lots of tiny air bubbles become suspended in it and it becomes a much thicker foam, right?
Would it be possible to use a SodaStream machine (or some similar carbonation machine) to make whipped cream by carbonating the cream until it becomes whipped cream?
Your title and your question body are somewhat different. Until now, answers seem to have been directed at the title.
In fact, whipping cream with a gas siphon is a thing. Your idea is known, and widely used. You can buy whipping siphons with rechargeable cartridges for the home kitchen, and these sprays of "whipped cream" you get in the supermarket are exactly that, a one-time siphon which contains liquid sweetened cream and "whips" with the gas pressure when you press the nozzle. I believe there are also such siphons built in in some large all-in-one professional espresso machines, so the barista can float a little bit of whipped cream on your drink on the push of a button.
As the other answers mentioned, you need a siphon which is designed for it. Not only does it have to use NO instead of CO2, but it also has to be engineered to be suitable for dealing with cream instead of a watery liquid. Soda stream is not such a siphon. There are, however, siphons which are multipurpose (just not ones manufactured by soda stream). They can handle both the carbonation of lemonade and whipping of cream, as long as you use the correct gas cartridge.
No, because the bottle would explode off the Soda Stream, spraying cream and foam all over your kitchen.
Per the Soda Stream FAQ:
No. Only water should be carbonated in the SodaStream Sparkling Water Maker. You risk damaging your Sparkling Water Maker, not to mention making a big fizzy mess! The money-back guarantee and the warranty are both invalidated if you carbonate any liquid other than water in your Sparkling Water Maker. Stick with plain, cold water and adding any one of our fantastic flavors - AFTER the water has been carbonated!
Speaking from personal experience, the Soda Stream won't tolerate anything even a little more viscous than water ... not even fruit juice. The liquid foams too fast and blows the bottle off the device. Cream would be a hilarious mess.
You could probably make a foam. But a foam does not whipped make.
Sodastreams use carbon dioxide wheras most cream whippers (which work pretty much exactly like a sodastream on the technical side) use nitrous oxide.
One issue is that carbon dioxide reacts with water to form acid so your whipped cream will be slightly sour.
Another is that carbon dioxide is far more water soluble so your cream will contain much more gas and probably in larger bubbles.
It's an interesting experiment but I don't think you'll get the effect you are looking for.
