For me it will always be my Dad's homemade root beer made with Hire's extract. Us kids would scour the new houses under construction for empty coke bottles - the small ones. We would make the root beer using yeast and sugar. We had a bottle capper and kept the filled bottles in a red radio flyer wagon. for the first several days we had to bring them out of the basement to set in the sun. I think we had root beer with good foam after about 10 days. So it was the anticipation that built up the flavor.