Other fermented milk

Overview

Fermented milk products are dairy foods that have been cultured with lactic acid bacteria such as Lactobacillus, Lactococcus, and Leuconostoc. The fermentation process increases shelf life, enhances taste, and improves digestibility of milk. These products range from liquid drinking yogurts to thick, strained cheeses, and their flavor profiles span from mild and creamy to sharply tangy.

Origin and history

Fermented milk is among the oldest preserved foods, with origins in the Neolithic domestication of ruminants. Spontaneous fermentation of raw milk by ambient lactic acid bacteria was likely discovered independently across multiple regions, including the Caucasus, Central Asia, the Middle East, and the Balkans. Documented references to cultured milk appear in ancient Indian, Persian, and Greek texts. The specific bacterial strains used today were first isolated and characterized in the late 19th and early 20th centuries, enabling industrial production of standardized products like commercial yogurt and kefir ^[1].

Varieties and aliases

• Yogurt (fermented with Lactobacillus bulgaricus and Streptococcus thermophilus)
• Kefir (fermented with a complex culture of bacteria and yeasts)
• Buttermilk (traditionally the liquid left after churning butter; cultured buttermilk is a modern variant)
• Sour cream (cream fermented with lactic acid bacteria)
• Crème fraîche (French-style cultured cream, higher fat content than sour cream)
• Skyr (Icelandic strained cheese, technically a fresh cheese but often classified with fermented milks)
• Filmjölk (Swedish ropy fermented milk)
• Ayran (Turkish salted yogurt drink)
• Lassi (Indian yogurt-based drink, sweet or savory)
• Laban / labneh (Middle Eastern strained yogurt)
• Jocoque (Mexican cultured milk product, similar to labneh or sour cream)
• Kumis (fermented mare’s milk, Central Asia)
• Viili (Finnish ropy fermented milk)

Culinary uses

Fermented milk is consumed directly as a beverage or spoonable food, and used as an ingredient in cooking and baking. Yogurt and kefir are common breakfast items, often paired with fruit, granola, or honey. Sour cream and crème fraîche are used as toppings for baked potatoes, tacos, and soups, or stirred into sauces to add richness and acidity. Buttermilk is a key component in baked goods such as pancakes, biscuits, and soda bread, where its acidity reacts with leavening agents. In Mexican cuisine, jocoque is used as a table condiment, a marinade for meats, and a base for dips. In Indian cuisine, yogurt is used in marinades (tandoori chicken), curries, and raitas. In Middle Eastern cuisine, labneh is spread on flatbreads or served with olive oil and za’atar.

Cross-cuisine context

Fermented milk products are a global category with strong analogues across many cuisines represented in Los Angeles. Mexican jocoque is functionally similar to Middle Eastern labneh and Greek strained yogurt, though its texture and tang vary by producer. In Korean cuisine, there is no direct analogue to fermented milk as a standalone product, but yogurt-based drinks (such as yakult-style beverages) are widely consumed. In Japanese cuisine, gyunyu (milk) is not traditionally fermented, but modern yogurt and drinkable yogurts are common. In Chinese cuisine, fermented milk is historically rare, though modern yogurt drinks are popular. In Armenian cuisine, matsun (fermented milk) is a direct analogue, used similarly to yogurt. In Persian cuisine, mast (yogurt) is a daily staple, served with meals, in dips like mast-o-khiar, and as a side to rice dishes. In Salvadoran and Guatemalan cuisines, crema (cultured cream) is a common table condiment, analogous to sour cream but typically thinner and less tangy. In Filipino cuisine, there is no traditional fermented milk analogue; modern yogurt is a recent introduction.

Notes for cooks

• Substitution: In baking, 1 cup of buttermilk can be approximated by adding 1 tablespoon of lemon juice or vinegar to 1 cup of milk and letting it sit for 5 minutes.
• Storage: Fermented milk products keep longer than fresh milk due to their acidity, but should be refrigerated and used by the sell-by date. Separation of whey is natural; stir to recombine.
• Signal characteristics: Fresh fermented milk should smell clean and tangy, not sour or yeasty. Mold or off-odors indicate spoilage. For yogurt, a smooth, unbroken curd is a sign of quality; for kefir, slight effervescence is normal.