Originally Posted by Brewtopia
I buy Root Beer Extract at my LHBS. It's enough for a 5 gallon batch and the directions are on the box. I substitute dark brown sugar for the granulated sugar and steep two vanilla beans in hot water and add that to the mix. I then keg and force carbonate. The brown sugar and vanilla add an extra richness.
If I had a keg system, that is the way I'd do it.
Without the kegging equipment, get an Igloo cooler, and a 2 pound chunk of dry ice. Mix up how you want, and pour into the cooler, with the dry ice. In an hour or so, it is ready to drink.
Note, this method only works for a large group of people, since it's going to go flat, a few hours after the dry ice evaporates. (Well, sublimates, really, but it's gone.)
I used to do this method, as a youngster, for large church gatherings. I think that is what started me on my hobby of homebrewing.