This is a popular Bulgarian drink typical also of other Balkan countries.
The boza is a thick, fermented beverage (containing up to 4 percent alcohol) with a sourest or sweetish taste.
The boza is made of various kinds of flour (barley, oats, corn, wheat), but boza of best quality and taste is made of millet flour.
We offer you directions for making boza at home. The recipe is meant for 5 litters.
5 l of water
2 teacupfuls of flour
2 teacupfuls of sugar
1 teacupful of boza or home-made ferment
How to cook:
Roast slightly the flour (to become rosy in color). Take care not to get it burnt. Mix it with a bit of lukewarm water. Pour the mixture into the pot filled with the rest of the water and put it on the plate. Add the sugar and leave the liquid to boil stirring it once in a while. Keep boiling for 5-6 minutes still stirring. Remove the pot from the fire and let it cool. Add 1 teacupful of boza or 1 teacupful of the home-made ferment. Leave the mixture in a warm place for 2-3 days to cause fermentation. When the boza is ready, pour it in bottles and store in a cool place (refrigerator).
Home-made boza ferment:
1-2 spoonfuls of slightly roasted flour
1 teacupful of tepid water
1 spoonful of sugar
How to make the boza ferment:
Mix the slightly roasted flour (take care to keep it from burning) with the water and stir well. Add the sugar. Leave the mess in a warm place for 2-3 days to ferment, stirring it from time to time.
Note: The teacupful of boza or home-made ferment can be replaced by 6-7 moistened and crumbled slices of wholemeal bread /or toast/, or by 6-7 spoonfuls of leaven. In this case before storage the boza has to be filtered (without pressing).
There is reason to suppose that for causing fermentation it is also possible to use a mixture of a little bit of yeast, water or milk, and a teaspoonful of sugar, left beforehand to rise.
Obviously, to become a good boza maker one has to experiment!