How long do eggs actually last?

Stand in an American supermarket and you'll find eggs in the refrigerated aisle. Stand in a European supermarket and you'll find eggs on a shelf, at room temperature, sometimes near the bread. Both countries are wrong. Both are also right. Let us explain.

The eggshell's natural defense

When a hen lays an egg, it comes out coated in a thin protective layer called the cuticle (or "bloom"). This invisible coating seals the porous shell and prevents bacteria — including salmonella — from getting in. With the cuticle intact, an egg can sit on a counter for weeks without spoiling.

Where the USA and Europe diverge

In the United States, federal regulations require commercial eggs to be washed and sanitized before sale. This removes the cuticle along with any pathogens on the shell. The egg is now clean — but also defenseless. Without the cuticle, bacteria can pass through the porous shell, so US eggs must be refrigerated to stay safe.

In most of Europe, washing eggs is actually illegal. Hens are vaccinated against salmonella, and the cuticle is preserved. Unwashed eggs can sit at room temperature safely. (If you wash them, you must then refrigerate — same logic, applied later.)

Both systems work. They just commit to different points in the chain of safety.

How long eggs actually last

The float test

The single most reliable way to check an egg's freshness without cracking it: drop it in a glass of cool water and watch what happens.

• Sinks and lies flat on its side: Very fresh. Less than a week old.
• Sinks but stands at an angle: 1-3 weeks old. Still good. Actually peels easier when boiled.
• Stands upright on the bottom: 3-5 weeks. Use today. Don't poach — the white will spread.
• Floats to the surface: Toss it. The air cell has grown so much the egg is buoyant. Almost certainly bad.

Why does this work? As an egg ages, moisture and gases pass through the shell, and the air cell at the rounded end of the egg gets bigger. A bigger air cell means more buoyancy. It's a fast, accurate visual proxy for age.

The smell test (when in doubt)

Even if the float test says an egg is fine, crack it into a separate small bowl before adding to your dish. A bad egg announces itself with an unmistakable sulfurous smell. Trust your nose more than any chart, including this one. Eggs are good at telling you when they've gone bad.

What about "sell by" and "best by" dates?

These are conservative. In the US, eggs are typically sold within 30 days of being packed and remain safe for another 3-5 weeks past their printed date if refrigerated properly. The dates protect retailers from liability — they're not a hard expiration.

The actual decoder: on US cartons, look for a 3-digit number (the Julian date — 001 is January 1, 365 is December 31). This is the day the eggs were packed. Add 30-45 days for "safe to use," or 21 days for "optimal quality."

Storage tips that actually matter

• Don't store eggs in the fridge door. The temperature swings every time you open it. Use a shelf.
• Keep them in the carton. The carton protects them from absorbing fridge smells (eggs are porous).
• Pointy end down. Keeps the air cell at the top, away from the yolk. Prolongs freshness.
• Don't wash eggs before storing. If you have backyard eggs, store them unwashed. Wash only right before you cook.

When in doubt, calculate it

We built a Storage Calculator that tells you exactly how long your eggs will last based on when you bought them and how they're stored. And a Freshness Tester that walks you through the float test interactively.