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Sourdough drink

Many years ago, when I still had no idea what sourdough is, I tried for the first time what even today I consider as the most flavorful drink I have ever tasted. I was in Bulgaria, where one day, a local friend offered me a traditional fermented drink. I poured it into a glass, I looked at it, and for a moment I hesitated to bring it into my mouth. It had an unappealing consistency and colour, even its name sounded rough and aggressive, it was called Boza.



Even though the initial hesitation, I was very curious, and I drunk it. It took me some moments to process the feelings and reach a verdict. I found it very unique and complex regarding its taste and mouthfeel. However, since I was negatively biased, I decided that I do not like it. For some reason though, after a while, I felt to give it a second try, and then simply I loved it, so much that I aimed to drink as much as I could the few days that I was planning to stay there.



Boza is a fermented cereal beverage, traditional to eastern European and Balkan countries, and Turkey. It has a very long history, initially appearing in the 8-9th century BC, but it became popular during the Ottoman period, when it took its name and began its journey from central Asia, spreading to many other areas. Because of being very nutritious, it gained the fame as the main ‘food’ of the Ottoman army.



It is made by simply fermenting cereal grains using a sourdough culture or nowadays even a baker’s yeast. Any grain can be used to make it, and thus boza can have different flavour and consistency characteristics, depending each time on the respective grain properties. However, in terms of flavour, millet-based boza is considered to be the best.



Other grains that are typically used are wheat and corn. In Turkey, it is typically prepared nowadays from whole wheat products, like bulgur.


In my experiments last weeks, I made even rye boza that similar to rye bread had a very intense taste and character, so that it made me feel full, with no appetite whatsoever, for many hours after drinking just a glass of it.



Boza has a great taste, a kind of a complex mixture of sweet and sour. At the same time, it is lightly alcoholic (1-2%) and bubbly because of the yeast fermentation. It is a ‘live’ product, meaning that the fermentation process goes on constantly, at a slower pace when in the fridge, but it still should be consumed relatively soon after being prepared so as not to become very aggressive. It is similar in concept to kombucha and kefir, but you can call it also a kind of beer since it is made out of grains. In Bulgaria where I got to know it, it is consumed for breakfast, together with a typical cheese pie.



Both whole grains and whole grain flour can be used to make it. In the first case, the grains are usually let to soak for a day in the water, before boiled and blended to form a kind of porridge. When flour is used, the same more or less porridge-like consistency is achieved after initially toasting and then cooking the flour in boiling water.



In both cases, the porridge mixture is let to cool down well (surely below 40°C) to prevent microbial death, before adding the sourdough culture to start fermenting on the grain material.



After one round of fermentation at room temperature, the sweetness is adjusted with the addition of sugar, the mixture is then bottled and transferred in the fridge to continue fermenting and carbonating. A couple of days later it is ready for consumption, something that is advised to take place during the following few days because the drink gradually becomes more aggressive in terms of alcohol plus gas content, and sourness.



Millet Boza



Makes approximately 1 lt of boza


  • 100 gr millet grains or flour *

  • 1 lt water and extra for adjusting consistency

  • 100 gr active sourdough **

  • 50 gr sugar***


* If it is difficult to find millet, use alternatively whole wheat or corn flour, or any other whole grain flour that you like

** Activate your sourdough by feeding your starter with the same flour used in the recipe

*** This is an indicative amount, you can adjust sweetness to your liking


- If you go with flour, add it into a pan and toast it slightly on medium heat. Add the water, bring to boil, and simmer for 10-15 min stirring frequently. It will thicken a bit and form a kind of porridge.

(Before adding the water remove the pan from the fire because it might splash and burn your skin)


- If you go with whole grains, let them soak overnight in water and then boil them for half an hour with some fresh water that exceeds a couple of fingers from the grain surface. After, blend the mixture with a hand blender to obtain again a porridge consistency.


- In both cases, let the porridge mix to cool down below 40°C and only then add the active sourdough culture. Mix it well, cover it with a lid, and let it ferment overnight at room temperature.


- Next day, depending on the type of flour you are using, it might change consistency and become more liquid. Scoop out with a spoon the water layer on the top (if there is any) and strain the rest.


- Add sugar, and mix well. At this point adjust consistency (if you prefer it more liquid) by adding extra water.


- Bottle and transfer in the fridge. Let it there for 1-2 days to become carbonated.


- Consume it in the next couple of days before it starts becoming very aggressive.

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