What does fermentation do to fireweed and currant leaves in this tea?

Fermentation is a natural, controlled process applied to harvested leaves. Unlike fresh or simply dried herbs, fermented leaves undergo enzymatic changes that develop their flavor and aroma compounds. For the fireweed leaves (Ivan-tea), this results in a deeper, more rounded aroma and a softer, less grassy taste compared to non-fermented versions. The currant leaves also benefit, with fermentation helping to mellow any sharp edges and integrate their bright, fruity-green fragrance more harmoniously with the fireweed. The outcome is a warm infusion with a fuller body and a complex, balanced character that many find more enjoyable than a standard herbal tisane. This traditional technique is valued for turning simple garden leaves into a soothing, caffeine-free beverage for quiet moments.