The simplest thing we can say about chaga (Inonotus obliquus | чага in Russian) is that it's our favourite mushroom, and we drink it because the rich, dark brew is delicious. Popular among 'superfood' and 'elixir' enthusiasts, a Google search will reveal a wide variety of literature about chaga's health benefits. Though many of those articles don't seem to be based on solid data, a decent number are peer-reviewed articles from very credible sources.  We source our chaga from some good friends in Quebec, Canada. Chaga grows mostly on birch, in Circumboreal forests. A chaga 'tea' (or extraction) is a traditional drink in Siberia and some parts of Scandinavia.