Hi to all Boza fans!
I live in Bosnia, working in a sweet shop that makes boza since 1961.
Bosnian versions of boza is summer type (light) mostly with corn and wheat at some ratio. Secret is long cooking on low fire, constantly mixing to avoid burning of mix.
Fermentation is simple, with bakers yeast at first, or with already fermented boza from earlier batch. Real taste of fresh boza is like having million dollars in a pocket. Bottled versions are full with potassium sorbate, potassium metabisulfite and sodium benzoate. Sweeteners are also very unhealthy and taste is corrupted greatly.
Bottled boza is bad, not recommended at all. Luckily there are still real craftsman who produce real thing. Natural boza is very delicate and good recipe require many steps and time to invest, but the result is worth it. Real boza is good for pregnant woman, persons with high blood pressure and for immune system. Maybe we should all learn from Japanese and their "sake" national pride beverage. Sake is preservative free by law and Boza should be also protected by law here in balkan states and free of preservatives. We should be all proud on our balkan beverage!