A sound echoing in the streets reminds us of cold winter nights in our childhood. With their familiar call of 'Boozaa!' street sellers carrying large metal jugs walk Istanbul's streets in the evenings, bringing a delicious traditional drink to our doors. Sadly boza sellers are becoming rarer today. Boza is a cold drink made from fermented grain and has a wonderful slightly acidic sweet flavour. It is a drink of great antiquity, first originating in Mesopotamia 8000-9000 years ago. The Greek historian Xenophon records that boza was made in eastern Anatolia in 401 BC, and stored in clay jars that were buried beneath the ground. This local speciality remained confined to the region, however, until the arrival of the Turks, who took to this nourishing drink and spread it far and wide under the name boza, a word deriving from the Persian buze meaning millet. Boza enjoyed its golden age under the Ottomans, and boza making became one of the principal trades in towns and cities from the early Ottoman period.

Until the 16th century boza was drunk freely everywhere, but the custom of making the so-called Tartar boza laced with opium brought the wrath of the authorities down on the drink, and it was prohibited by Sultan Selim II (1566-1574). In the 17th century Sultan Mehmed IV (1648-1687) prohibited alcoholic drinks, in which category he included boza, and closed down all the boza shops. The 17th century Turkish writer Evliya Çelebi tells us that boza was widely drunk at this time, and that there were 300 boza shops employing 1005 people in Istanbul alone. He also describes a type of non-alcoholic sweet boza of a milk white colour made for the most part by Albanians.
At this period boza was widely drunk by janissaries in the army. Boza contained only a low level of alcohol, so as long as it was not consumed in sufficient quantities to cause drunkenness, it was tolerated on the grounds that it was a warming and strengthening beverage for soldiers. As Evliya Çelebi explained, 'These boza makers are numerous in the arm

A small quantity of mature boza is then stirred into each batch, and the mixture left to ferment. When small bubbles appear, the boza is ready.
Boza is produced in most Turkic regions, but not always using millet. The flavour various according to the cereal which is used. In Kirghizia, for instance, boza is made with crushed wheat, in the Crimea with wheat flour, and in Turkmenistan with coarsely ground rice meal. In a scientific study of boza carried out by the Turkish Science and Technology Institute for Vefa Bozacisi, the drink was found to be extremely healthy and nourishing. One litre of boza contains a thousand calories, four types of vitamins A and B, and vitamin E. During fermentation lactic acid, which is contained by few foods, is formed, and this facilitates digestion.

But if you do not have the patience to wait so long for your boza, then listen out on winter nights for the cry of 'Boozaa!' ringing through the cold air.

* Hande Basman Düler is a freelance writer