TL;DR: YMMV, but from my understanding of the physics, this is an effective way to bloat with soda!
The reason floats froth like they do isn't because of some chemical reaction; it's the same mechanism as Diet Coke + Mentos, actually.
Essentially, CO2 becomes a gas again when it has something to grow from. This can be a rough surface (which is why bottles need to be smooth on the inside) or other bubbles (which is how shaking sodas makes them explode).
Ice cream makes for an effective surface in this regard, giving the CO2 lots of places to become gaseous, which is what makes a float froth; what's special about floats is that the sugar and cream content of ice cream makes the liquid thicker, resulting in more dramatic and longer-lasting foam.
In theory this works with any sugary ice cream and well-carbonated soda; root beer happens to be very sugary already, so the liquid is even thicker.
Whether the thickness of the resulting foam results in a more satisfying bloat is a matter of perception and taste, but the combination of the heaviness of the ice cream and the expansion of the soda decarbonating may be exactly what you're looking for.
2 years
