I'm pickin' up what you're puttin' down...and if I was just brewing a batch here and there for myself, who cares...however, this is for my kids, who will probably drink a lot of it...and I don't want to have to ration it out for fear they might drink enough of it to have a problem down the road. That's not to say we let them drink soda all day anyway, I just don't want to have to worry about them getting cancer or liver damage from it more than we are already concerned about obesity or their teeth rotting out. Maybe it's nothing...I just don't want to take that chance on me kids, ya know?
I just don't see any recipes that indicate how to replace sassafras with wintergreen, or any other herb. I'm an experienced all-grain brewer, but these roots and herbs are completely new to me, so I don't know how to substitute anything yet...and there is virtually zero documentation, (including the nearly worthless book I just bought) that has a decent written description of the flavors of the various ingredients.
I hear what you're saying. I don't know if I've ever seen a home recipe that contains wintergreen. The Creswell book uses a LOT of sasafrass!! Personally, I've only ever made root beer from the Homemade Soda Company extracts, but the recipes in his book for kvass and switchel are both pretty good.