Doogh

Doogh (in, dooqh, also dugh), also called dugh, abdug, or tahn (the last two mostly by Armenians) is a naturally-carbonated yogurt beverage popular in Iran, Afghanistan, Azerbaijan, Armenia and to a lesser extent in other parts of the Middle East and Caucasus.

Doogh is prepared by beating unflavored yogurt until smooth, and then diluting with water to a consistency similar to whole milk. Salt (and sometimes pepper) is added, and commonly dried mint is mixed in as well. Carbonation is achieved by letting it ferment. Doogh is generally served chilled, or over ice. A variation is adding diced cucumbers to provide an extra "crunch".

A popular yogurt-based drink, "lassi," is considered a staple by many Indians and Pakistanis and holds a high status in Indian cuisine and Pakistani cuisine. Being a yogurt drink similar to doogh, it is very easy to make and is used in the same way as doogh (served with hearty meals). However, lassi is sometimes flavoured with fruit juices and is not carbonated. In many respects, it is similar to the Turkish ayran.

The word Doogh is a noun form from the Persian verb دوشیدن (Dushidan) which means "to milk" thus doogh means "what comes from milking".

Carbonation
Traditionally, doogh is left unrefrigerated for 2-3 days in order to allow the yogurt cultures to ripen and carbonate the beverage. The carbonation in commercially-produced doogh however, comes from carbonated water being used in the dilution of the yogurt. Because of this, commercially-produced doogh, generally has harsher carbonation and coarser bubbles.