Buttermilk
Buttermilk refers to a number of dairy drinks. Originally, buttermilk was the liquid left behind after churning butter out of cream. It also refers to a range of fermented milk drinks, common in warm climates (e.g., Middle East, Pakistan, India, or the Southern United States) where fresh milk would otherwise sour quickly. It is also popular in Scandinavia and the Netherlands, despite the colder climates.