"sour cream"

Sour cream is a fermented dairy product made by adding lactic acid bacteria cultures (typically Lactobacillus lactis) to regular cream, resulting in a tangy, thick condiment. The fermentation process causes the milk fat to curdle slightly and develop its characteristic acidic flavor and rich texture. The product typically contains 18-20% milk fat and maintains a smooth, pourable consistency that becomes increasingly thick as fermentation progresses. Sour cream differs from crème fraîche primarily in bacterial cultures used and resulting tang level, with sour cream being more acidic and American in origin, whereas crème fraîche is creamier with a milder taste.

Sour cream functions as both a cooking ingredient and finishing condiment across numerous cuisines. It is essential in Eastern European and Russian cooking, appearing in borscht, stroganoff, and pierogi fillings. In American cuisine, it serves as a baked potato topping, component in baking (cakes, pancakes, and quick breads where it adds moisture and tang), and base for sauces and dressings. It is used in Mexican cuisine atop chiles rellenos and tacos, and in savory applications to balance spicy dishes. Its acidity makes it valuable for marinating proteins and enriching soups, while its thickness aids in emulsification.