With a siphon, do we make an emulsion or a mousse?

 
With a siphon, do we make an emulsion or a foam? The question is wrong, obviously, because it all depends on what we put in the siphon.

If we put water or an aqueous solution, then we will have a very different result than if we had first made a mayonnaise, which is already an emulsion, with droplets of fat dispersed in an aqueous solution.

Moreover, it also depends on the gas used to pre-fill the siphone. If a carbon dioxide cartridge is used, this gas will dissolve in an aqueous phase and will allow to obtain an effervescence, when the liquid in which it is dissolved will be put back to the atmospheric pressure, when the siphon is activated.

But if we used nitrous oxide, which will dissolve less, we can obtain -or not- an overflow.

Let's imagine the siphon turned upside down, with the liquid in the lower part. If we slowly open the valve, then a liquid will simply be pushed out of the siphon. But if we open the siphon more quickly, then gas can disperse in the form of bubbles, which will produce an expansion.

And if the liquid is an emulsion, with droplets of fat dispersed in the liquid, then bubbles will be added, and we will get an overflow emulsion.

In short, we can do what we want with a siphon: it is up to us to understand and act accordingly.