of cream or sour cream or yoghurt

Sour cream is a dairy product produced by fermenting regular cream with lactic acid bacteria cultures (Lactobacillus lactis and related species), which produces lactic acid and gives the product its characteristic tangy flavor and thick texture. Native to Eastern Europe, sour cream typically contains 18-20% milk fat and has a smooth, pourable consistency. It differs from crème fraîche, which has a higher fat content (40-45%) and milder flavor, and from yogurt, which is produced by fermenting milk rather than cream.

The fermentation process lowers the pH, creating a naturally acidic product with a distinctive sour taste and creamy mouthfeel. Sour cream is thicker than regular cream but less thick than some yogurts, with a slight tang that intensifies with age.

Sour cream is extensively used in Eastern European, Russian, and Mexican cuisines as both a condiment and cooking ingredient. It is commonly served as a topping for baked potatoes, soups (particularly borscht), and other savory dishes, and is a staple accompaniment to tacos and enchiladas in Mexican cuisine. In cooking, it enriches sauces, marinades, and baked goods, including cakes, cookies, and quick breads. Its acidity and fat content make it valuable in tenderizing meats and providing moisture to dense baked goods. It is also used in salad dressings and dips.