By “zip” I mean too sharp a flavor. Sometimes a nice, mellow, creamy style of root beer is called for, and I fell this is one of them. Ordinarily I drink Barq’s, but for a RBF, A&W is my first choice.
Very simple:
Dreyer’s Vanilla Bean ice cream
Henry Weinhard draught-style root beer
The real question is which goes in first - the ice cream or the root beer.
It is? 
If you put the root beer in first, you never know how much ice cream will fit. The Correct Way™ to do it is to cram as much ice cream into the glass as you can without shutting off all nooks and crannies, then slowly add root beer. As it foams up, you can spoon out Goodness, add root beer as you deplete the glass. Done correctly, you will end up with about 1/2 glass of root beer infused with melted ice cream, which you then chug so fast it gives you a killer headache. 
How do you put the ice cream in after the rootbeer? That would just make a mess and waste your perfectly good rootbeer! You fill a very large mug with icecream (or if you have some self restraint, put in a single scoop) Then SLOWLY fill the mug with your (good and cold) rootbeer.
There is no other way!
I am stopping at the store on the way home for some roobeer and icecream, who is with me?
And I learned last night: ALWAYS use “fresh” rootbeer. I accidentally made a psuedo-float last night with completely flat root beer. Yuck…
There used to be a chain of ice-cream shops in St. Louis called Velvet Freeze. They had deal where if you got a root-beer float (with IBC), they’d keep refilling the glass with the rootbeer as long as you still had ice-cream in the glass!
Incidentally, I got addicted to IBC at an early age, because it was a local brand for me - it didn’t get the wider distribution until much later. When I was in college down here in Florida, I’d always bring 2-liters of IBC back from vacations.
First one scoop of ice cream and enough root beer to cover the scoop. Then mush up the ice cream so that it’s basically disolved in the root beer. Put more ice cream in the glass - 2 or 3 scoops is usually enough depending on the size of the glass. Then fill the glass with root beer. Make sure you have a straw at hand to suck up the foam before it can completely overflow.
Common Tater, most root beer doesn’t have caffeine but Barq’s does.
I just introduced my 5yr old to the Root Beer Float this past weekend, and he is addicted. I used AW and Breyers with vanilla bean. Now that I know I have a partner in crime, I plan on experimenting with different brands of Ice Cream.
The way around this is to pour in a small amount of root beer, then cram in the ice cream, followed by more root beer until the head threatens to topple over.
I blame all of you. I just brought home some Breyers and made a Root Beer float. I
It was delicious BTW. 
Jim
I’ll second the Blue bell Homemade Vanilla ice cream - though it is only available in “17 southern states” according to Wikipedia.
*As of 1997, Blue Bell Homemade Vanilla was the best-selling single flavor of ice cream in the United States. Also cited from Wikipedia.
I feel sorry for people that do not have the opportunity to try any Blue Bell products.
My first exposure to root beer floats was when I was little Mississippi boy visiting folks in Plain, Wisconsin. We went to the A&W stands sometimes, but they also made floats at home – always with A&W Root Beer though.
*Is it my imagination or did one of the vanilla ice creams they used have a sort of “micro-micro-gritty” feel to it, just before it melted?
I don’t really know how to describe it and it was so long ago, but it was a less-than-creamy feel on the tongue, like I said, right before the ice cream melted. There was nothing wrong, it just seemed the ice cream had a different texture.*
And I loved it.
Does anybody know of a brand in that part of Wisconsin that would fit that description?
BTW, the folks I stayed with called root beer and chocolate ice cream brown cows.
Yeah. Ice cream with embedded Oreo cookie bits has the same texture.
No, not it (long before IC/OC were available commerically). It was even finer than that and only lasted until the ice cream naturally began to melt.
Or, it could be I was hallucinating.
I know. Just drawing a comparison.
Theoretically, you had a vanilla with bits of vanilla bean, like Breyer’s.
No, you aren’t tripping. I remember that the ice cream got…“icey” on the surface. Different than its usual texture.
Use root beer from the Jones Soda Company. Maggie Moo’s ice cream parlor chain carries it. When they make a float, they’ll give you two or three big scoops of ice cream, while most other restaurants only give you one.
EXACTLY what I was talking about up thread. Thank you!
:o I thought you fill the mug up about 2/3 and then scooped in ice cream. I didn’t know!
On Brown cows -
A local burger chain (which went belly-up about 11 years ago) sold brown cows, but they were basically a vanilla shake, made with root beer instead of milk.