Boza is a thick, sweet-and-sour fermented grain drink from Turkey and the Balkans – Bulgaria, Albania, North Macedonia, Bosnia and neighboring countries. It’s made by cooking grain (millet, maize, wheat or rice, depending on the region) into a thin porridge, sweetening it and fermenting it briefly with a starter. The result is pale, creamy and lightly fizzy, somewhere between a drinkable pudding and a sour malt drink, with very little alcohol. In Turkey it’s a winter drink, served with a dusting of cinnamon and roasted chickpeas (leblebi); in Bulgaria it’s sold bottled year-round and famously paired with banitsa pastry for breakfast.
How Boza Is Made
Turkish boza is usually made from a mix of maize, wheat and rice, or their flours, cooked with water. The starter is typically some boza from a previous batch, or sourdough or yogurt, which brings lactic acid bacteria and yeasts (Altay et al., 2013). Both lactic and alcoholic fermentation happen: bacteria make it sour, yeasts give the fizz and a trace of alcohol. It’s fermented only briefly, so it stays sweet; homemade boza left longer gets sourer and a little stronger.
In Istanbul, Vefa Bozacısı, opened in 1876, still serves boza from its original shop, where the glass Atatürk drank from in 1937 is on display.
The Microbes
An analysis of three unpasteurised Bulgarian bozas found a rich, varied community: lactic acid bacteria including Lactobacillus fermentum, L. parabuchneri, L. coryniformis, members of the L. casei group, Weissella confusa, Leuconostoc citreum and Pediococcus, plus yeasts such as Pichia fermentans and Torulaspora (Osimani et al., 2015). Many commercial bozas are pasteurised, so live cultures depend on the product – homemade boza has them.
Lab studies have found peptides in boza that inhibit angiotensin-converting enzyme (the target of some blood pressure drugs) and that remained active after simulated digestion (Kancabaş & Karakaya, 2013), but there are no human trials. Treat boza as a traditional sweet drink – it contains a fair amount of sugar – rather than a health supplement.
Tips
- Grain: millet gives the classic pale-yellow Balkan boza; maize gives the Albanian style; bulgur, rice or a mix are common in Turkey.
- Starter: a few spoonfuls of a previous batch or of sourdough starter work best; plain live yogurt works too.
- Timing: it’s ready when it’s pleasantly sour and slightly fizzy, usually 1–3 days. Longer makes it sourer and a bit more alcoholic.
- Too thick? Thin with cold water before serving. Separating? Stir – that’s normal.
Related grain ferments: Russian kvass, Egypt’s wheat bouza (a different drink despite the name), and Greek trahanas.