Carbonation.

@XOIIO I’m aware it’s carbonated – obviously. I’m wondering if it is more carbonated than most sodas or if it’s a property of that particular kind of soda. You haven’t really answered anything.

Sassafras roots and bark contain natural foaming agents. Also, additional foaming agents such as yucca or quillaja extracts, are often added to increase root beer’s froth, head or foaminess. Source: http://www.root-beer.org/questions.htm

So much frothier than what?

As @bkcunningham said, it has to do with ingredients, but it also has to do with how you pour it. It’ll froth more if you pour it straight down to the bottom of the glass. And of course, it froths a lot when you put the ice cream in. I prefer chocolate ice cream. Bring your straw. Such off the froth before it slides down the outside of the glass.

@asmonet That’s what I meant, it has more carbonation, and it is a thicker liquid. Also what @bkcunningham said.

Ice.

Mine has got Vanilla ice cream in the glass and boy does that FOAM !

It seriously took me 28 years, looking at my family like they were stupid, and 2 stints n the military to learn that ice reduces froth. Ice cream makes soda froth due to the carbon in the soda reacting to the breakdown of the ice cream. I don’t know why I know that before the ice trick. Funnily, I can get way more elaborate in the explaining of ice cream floats.