Quick bread leavening agents include a weak base, such as baking soda (sodium bicarbonate) plus a weak acid, such as cream of tartar, lemon juice, or cultured buttermilk, to create an acid–base reaction that releases carbon dioxide. (Quick bread leavened specifically with baking soda is often called "soda bread".) Baking powder contains both an acid and a base in dry powdered form, and simply needs a liquid medium in which to react. Other alternative leavening agents are egg whites mechanically beaten to form stiff peaks, as in the case of many waffle recipes, or steam, in the case of cream puffs. Nevertheless,
Buttermilk Buttermilk Buttermilk is a dairy drink. Originally, buttermilk was the liquid left behind after churning butter out of cultured cream. This type of buttermilk is now specifically referred to as traditional buttermilk and the fermented dairy product is known as cultured buttermilk. Cultured buttermilk is common in warm climates (e.g., Afghanistan, the Balkans, India, the Middle East, Nepal, Nicaragua, Pakistan, Sri Lanka, Turkey, and the Southern United States) where unrefrigerated fresh milk sours quickly, as well as in colder climates, such as Scandinavia, Ireland, the Netherlands, Germany, Poland, Slovakia, Slovenia, Croatia, and the Czech Republic. This fermented dairy product, known