Sauna fragrance Birch is made of pure Finnish dried birch leaves. The package includes 4 bags of birch leaves. Soak the bag in the warm water intended for throwing on the sauna coals. Pour the water on the hot coals according to preference and enjoy the genuine aroma of birch in your sauna. If you allow the bag to dry after use, its scent will suffice for re-use in several saunas.