A starter culture is a group of beneficial microorganisms, such as bacteria, yeasts, or molds, used to initiate fermentation in various foods. It often contributes a tangy, mildly sour flavor and a varying texture, depending on the specific product, such as the creamy consistency of yogurt or the bubbly fizz of sourdough bread. In international cooking, starter cultures are essential for producing traditional fermented foods like kimchi, sauerkraut, kefir, and cheese, imparting distinctive flavors and preserving ingredients. Historically, these cultures have played a vital role in food preservation and cultural identity, with each region developing its unique microorganisms and fermentation techniques over centuries.