Sour cream

Sour cream is a dairy product made by fermenting regular cream with certain lactic acid bacteria, which sour and thicken it. Its tangy flavour and dense texture set it apart from plain cream, and it is a common accompaniment in many kitchens across Latin America and North America.

History

Its origins lie in a simple practice: cream skimmed from the top of milk was left to ferment at a moderate temperature. The bacteria that developed thickened the cream and made it more acidic, which also kept it from spoiling quickly. The exact time and place where this practice began are not documented with precision.

With pasteurisation and industrial production the process changed. Today the cream is standardised for fat content, organic acids such as citric acid are added, and it is homogenised and heat-treated at a high temperature before a starter culture is introduced. During fermentation the pH falls from around 6.5 to about 4.6, and the milk proteins form a network that gives the product its characteristic body. National regulations, such as those of the US Food and Drug Administration and Canadian food rules, set minimum fat and acidity levels and list the permitted additives.

Culture

Across Latin America it takes different names depending on the country. In Costa Rica and Venezuela it is called natilla, a sour cream with a low fat content of roughly 10 to 15 per cent. In Colombia, on the plains of Córdoba, Sucre and Bolívar, people speak of suero atollabuey, a typical sour cream that accompanies almost any meal. In Mexico it is known as crema fresa or crema espesa, and it is still sold directly at some ranches outside the most populated cities.

Its presence extends into the Latin American diaspora, where Mexican and Latin American supermarkets in the United States stock it regularly. It is often served alongside hot dishes, soups and sauces, because its combination of acidity and body offers a counterpoint to spicy food.

Trivia