What Is Egg Yolk?
Egg yolk is the yellow-orange part at the center of an egg and is rich in fat and nutrients. Much of an egg’s energy and many of its nutrients are in the yolk; it is much higher in fat and calories than the white.
Its creamy, rich texture gives sauces body and thickness; its natural emulsifiers also bind oil and water. This makes it essential in mayonnaise, hollandaise, and many creams.
Egg Yolk Nutrition
Egg yolk is high in calories, providing approximately 322 kcal per 100 g; it is rich in fat (~27 g), protein, and various vitamins and minerals. It is high in cholesterol; people watching their cholesterol are advised to consume it in moderation.
How Should Egg Yolk Be Eaten?
Egg yolk is nutritious but rich in fat and cholesterol, so it is eaten in moderation as part of a balanced diet. Like any egg product, it carries a risk of Salmonella when eaten raw; cooking it thoroughly or using a pasteurized product is safer.
This is general information; egg yolk is a food and is not a substitute for medical treatment.
How to Separate and Choose Egg Yolks
A fresh egg yolk is firm, rounded, and holds together easily, which makes it easier to separate cleanly. A spread-out, watery yolk may be a sign of staleness; using fresh eggs matters for both flavor and use.
- A fresh egg yolk should be firm and rounded
- A yolk that holds together easily is fresher
- A spread-out, watery yolk may be stale
How to Store Egg Yolks
Store separated egg yolks briefly in a sealed container in the refrigerator, covered with a little water to keep them from drying out; because they dry quickly, they are recommended for use within 1–2 days. Whole eggs last longer in the refrigerator in their shells.
Using Egg Yolks in the Kitchen
Egg yolks are used most often in mayonnaise, hollandaise, pastry cream, custard-like desserts, pasta sauces, and for glazing dough. Their emulsifying and thickening properties bind sauces; for glazing, brush them over dough.
Why Does Egg Yolk Bind Mayonnaise?
Natural emulsifiers in the yolk (such as lecithin) disperse and stabilize oil droplets in water; this allows a creamy emulsion (mayonnaise) to form without the oil and water separating.
Frequently Asked Questions
Can egg yolk be eaten raw?
Raw egg yolk is not recommended because of the risk of Salmonella; use pasteurized eggs in recipes containing raw yolk, such as homemade mayonnaise.
Why are egg yolks separated from egg whites?
Some recipes call for only the yolk’s thickness and richness (cream, sauces) or only the white’s foam (meringue); for this reason, eggs are separated into yolks and whites.
Can egg yolks be frozen?
Yolks can gel when frozen on their own, so it is recommended to mix in a pinch of salt or sugar before freezing. This helps them remain usable after thawing.