Yes, same here, it is hard to find the correct juniper branches. The author indicated that the species of juniper from the states taste woody and a bit piney as well. I used juniper berries as a trial.
Different book in the pic, but I read that one too. This is my sahti. Every year I try to make it a little more authentic. This time I was able to use actual Finnish bakers yeast. Never used the juniper branches, just berries. It's one of the things I'm looking to do next time.