We can't officially pinpoint what's doing it, but I think you've come to a pretty clear conclulsion - manufactured root beers have a lot of ingredients in them, and obviously something in there is doing this. It could possibly be a preservative that hasn't been added to the natural root beer.
Wish I knew what it was, for curiosity's sake!Beer and Pepsi.?
Wierd I've felt the same way. I've wondered if there was Msg in it because after I drink root beer I feel the same as when I eat some chinese food.Is red bull beer or an energy drink?