yolks

Egg yolks are the nutrient-rich, lipid-dense centers of chicken eggs, separated from the albumen (white). They consist of a yellow or golden sphere surrounded by the vitelline membrane and suspended in the albumen by the chalaza—cord-like structures that maintain the yolk's position within the shell. The coloration ranges from pale yellow to deep golden-orange depending on the hen's diet, particularly pigments from maize and xanthophyll-rich feeds.

Yolks contain approximately 50% water, 30% lipids (including cholesterol and phospholipids), and 16% proteins, along with vitamins and minerals. They possess a rich, slightly nutty flavor that intensifies when cooked, and their emulsifying properties—derived from lecithin—make them invaluable in both sweet and savory preparations.

Egg yolks function as a critical binding, emulsifying, and enriching agent across global cuisines. In French cuisine, they form the base of emulsified sauces such as hollandaise, béarnaise, and mayonnaise, while in baking they contribute moisture, richness, and structure to custards, cakes, and pastry creams. In Asian cuisines, particularly Chinese and Japanese, yolks are cured, salted, or preserved to create distinctive umami-rich ingredients for congee and baked goods. Yolks also serve as the primary thickening agent in custards, sabayon, and liaison preparations. They are frequently used whole in preparations where their color and richness are desired, or separated when only their emulsifying or binding properties are needed.