Doogh () is a cold and savoury Persian drink. It is made with fermented milk. Unlike its sister beverage of Turkish origin, ayran, Doogh is not diluted yogurt. According to the Iranian Ministry of Food Standards, Doogh "is a drink resulting from lactic fermentation of milk whose dry matter is standardized by diluting yogurt (after fermentation) or buttermilk (before fermentation)."
Production
Milk and plain yogurt, at a ratio of 15:1, are mixed and placed on low heat until uniformly warm. Salt is added and the mixture is poured into a closed container and placed in a warm area for 3–4 days, after which it is ready to serve. The longer the drink is left to ferment, the more savoury it becomes. Many subcultures in Iran prefer a longer fermentation period.
Etymology
Doogh has historically been referenced in Persian literature as the representation of a "sour version" of milk. The history of this word is uncertain. It is present in Avestan scripture, and essentially seems to have been another word for milk, or for the product of milking thus, the word Doogh derives from the Persian word for milking, dooshidan.
History
Doogh is an Iranian fermented drink that has long been a popular drink and was consumed in ancient Iran (Persia).
Doogh is mentioned in Persian literature from the middle period.