Overview

Buttermilk is a dairy drink that exists in two distinct forms. Traditional buttermilk is the thin, tangy liquid left behind after churning butter from cream. Cultured buttermilk, the common commercial product today, is pasteurized skim or low-fat milk that has been fermented with lactic acid bacteria to produce a similar tangy flavor and thickened texture.

Origin and history

Traditional buttermilk has been produced wherever butter is churned, for as long as humans have made butter. It was a common byproduct in European, Middle Eastern, and South Asian dairying traditions. In the United States, traditional buttermilk was widely consumed until the early 20th century, when centralized butter production and refrigeration reduced its availability. Commercial cultured buttermilk was developed in the 1920s as a shelf-stable substitute, using bacterial cultures (typically Lactococcus lactis and Leuconostoc citrovorum) to replicate the sour taste and thick body of the traditional product [1]. In warm-climate regions such as the Middle East, India, and the Southern United States, fermented milk drinks analogous to buttermilk have long been made by allowing fresh milk to sour naturally, a preservation technique that predates mechanical refrigeration [2].

Varieties and aliases

  • Traditional buttermilk: The liquid byproduct of butter churning. Thin, slightly acidic, with occasional flecks of butterfat.
  • Cultured buttermilk: Commercial fermented milk product. Thicker than traditional buttermilk due to added milk solids or stabilizers.
  • Doogh (Persian): A carbonated or still yogurt-based drink, often diluted with water and flavored with mint, salt, or dried lime. Related to buttermilk in its fermented dairy character.
  • Chaas (Hindi/Urdu): An Indian buttermilk drink made by churning yogurt with water and spices. Distinct from Western buttermilk but functionally analogous.
  • Tan (Armenian): A diluted yogurt drink, sometimes carbonated, similar to doogh.
  • Kefir: A fermented milk drink made with kefir grains. Tangy and effervescent, sometimes used as a buttermilk substitute in baking.

Culinary uses

Cultured buttermilk is widely used in American and European baking. Its acidity reacts with baking soda to produce carbon dioxide, leavening biscuits, pancakes, scones, and quick breads. It also tenderizes gluten, yielding a softer crumb. In Southern U.S. cuisine, buttermilk is a key ingredient in fried chicken marinades (the acid tenderizes the meat) and in buttermilk pie, a custard dessert. In South Asia, chaas is drunk as a cooling digestive beverage, often seasoned with roasted cumin, black salt, and mint. In the Middle East and Iran, doogh is served alongside grilled meats and rice dishes. Traditional buttermilk, where available, is drunk plain or used in soups and cold borscht preparations in Eastern European and Baltic cuisines.

Cross-cuisine context

Buttermilk has direct analogues across multiple cuisines in the Yum corpus. In Persian cuisine, doogh is a fermented yogurt-water drink that mirrors buttermilk’s tang and digestive function, though it is often carbonated and flavored with mint. In Armenian cuisine, tan serves a similar role as a cold, salty yogurt drink. In Indian cuisine, chaas is the closest analogue: a spiced, diluted yogurt drink consumed as a meal accompaniment. In Filipino heritage cooking, a mildly soured coconut milk is used in some recipes to provide a tangy depth analogous to buttermilk, though the base is plant-based. In Salvadoran cuisine, crema salvadoreña is cultured cream that shares buttermilk’s fermentation process and tang, though it is thicker and higher in fat. In Russian and Lithuanian cold soups (kholodnik, šaltibarščiai), buttermilk or kefir provides the sour dairy base for beet and cucumber soups. No direct analogue exists in Korean, Japanese, or Chinese cuisines, where fermented dairy beverages are historically uncommon.

Notes for cooks

  • To substitute buttermilk in baking: add 1 tablespoon of lemon juice or white vinegar to 1 cup of milk and let stand for 5 minutes. The acid level will approximate cultured buttermilk.
  • Buttermilk freezes well for up to 3 months. Thaw in the refrigerator and shake or whisk before use, as separation may occur.
  • Traditional buttermilk is thinner and less tangy than cultured buttermilk. If a recipe calls for cultured buttermilk, traditional buttermilk may not provide enough acidity for proper leavening.