egg yolks

Egg yolks are the nutrient-rich yellow or golden centers of avian eggs, consisting of approximately 50% water, 30% fat, and 16% protein, along with vitamins and minerals. They are present in the eggs of domesticated chickens, ducks, quail, and other birds, with chicken yolks being the most widely used in culinary applications. The yolk is enclosed by the vitelline membrane and suspended within the albumen (egg white) by the chalazae. Yolks vary in color from pale yellow to deep orange depending on the bird species, diet, and feed composition—free-range and corn-fed birds typically produce richer, darker yolks. The yolk contains lecithin and other emulsifiers, making it essential for binding and stabilizing sauces and batters.

The flavor profile ranges from mild and buttery to distinctly rich, with higher levels of carotenoids producing more flavorful, golden yolks. Pasteurized and unpasteurized yolks are available commercially, with pasteurization killing potential pathogens while affecting viscosity and coagulation properties.

Egg yolks are fundamental to countless culinary preparations across world cuisines. They serve as primary emulsifiers in mayonnaise, hollandaise, béarnaise, and other classical French sauces, where their lecithin content stabilizes fat and water. In baking, yolks enrich doughs, custards, ice creams, and pastry creams, contributing color, moisture, and structure. They are essential in custard-based desserts, zabaglione, crème brûlée, and lemon curd. In Asian cuisines, yolks are used in noodle doughs, egg puddings, and as garnishes. Yolks also thicken soups, enrich pasta doughs, and are whisked into vinaigrettes. Their coagulation properties make them useful for clarifying stocks and broths. Whole yolks, separated yolks, or yolk-based preparations can be heated gently to soft-cooked or poached consistency, or incorporated raw into dressings and sauces destined for immediate consumption.