How Long Eggs Last, and Why You Should Not Wash Them

Eggs are one of the most common foods in a home kitchen and one of the most misunderstood when it comes to storage. The USDA's Food Safety and Inspection Service (FSIS) and the FDA both publish egg-specific guidance, and a few of their answers run against habits many people picked up at home.

1. The reason eggs need care: Salmonella

FSIS explains that even unbroken, clean, fresh shell eggs may contain Salmonella Enteritidis bacteria. The FDA's egg safety fact sheet describes what infection usually looks like: diarrhea, fever, abdominal cramps, and vomiting starting 12 to 72 hours after infection, typically lasting 4 to 7 days. Most people recover without treatment, but the FDA notes the risk of severe illness is higher for children, older adults, pregnant women, and people with weakened immune systems.

That is why egg cartons not treated to destroy Salmonella must carry a safe handling statement: keep eggs refrigerated, cook eggs until yolks are firm, and cook foods containing eggs thoroughly.

2. Should you wash eggs? No.

FSIS answers this one directly: it is not necessary or recommended for consumers to wash eggs. Washing at home can increase the risk of contamination, because wash water can be "sucked" into the egg through the pores in the shell.

Commercially, that problem is handled differently. FSIS says government regulations require processors to wash and sanitize USDA-graded eggs using approved compounds and at temperatures that keep wash water from being drawn into the egg. In other words, graded eggs from the store have already been washed under controlled conditions.

3. Where to store them

Both agencies give the same storage instructions:

• Refrigerate at 40°F or below, as soon as possible after buying. The FDA suggests using a refrigerator thermometer to check.
• Keep eggs in their original carton.
• Store them in the coldest part of the refrigerator, not the door.

FSIS also explains why temperature swings matter. A cold egg left out at room temperature can "sweat," and that moisture helps bacteria move into the egg, while any Salmonella in or on it can multiply at room temperature. FSIS says refrigerated eggs should not be left out more than 2 hours.

4. How long eggs keep

From the FDA's egg safety fact sheet and FSIS:

FSIS explains why hard-cooked eggs have a shorter life than raw ones: cooking leaves a thin layer of water on the egg's surface under the shell, which gives bacteria a favorable place to grow.

To freeze eggs, the FDA says to beat the yolks and whites together first.

5. What the dates on the carton mean

FSIS sets rules for date codes on USDA-graded eggs:

• An expiration-type date ("EXP," "Sell By," or "Not to be sold after") can be no more than 30 days from the packing date.
• A quality-type date ("Use by," "Use before," "Best before") can be no more than 45 days, counting the packing date.

So a "Best before" date on a USDA-graded carton is at most about six and a half weeks after packing, and the FDA's 3-week best-quality guideline is measured from when you bring the eggs home.

6. What the grade means

FSIS says USDA grading for quality is voluntary, but the grade shield means a licensed USDA grader checked the eggs. There are three consumer grades:

• Grade AA: thick, firm whites and high, round yolks. Best for frying and poaching, where looks matter.
• Grade A: like AA, but with whites that are "reasonably" firm. The grade most often sold in stores.
• Grade B: thinner whites and flatter yolks. Rarely sold at retail; usually used for liquid, frozen, and dried egg products.

Grade is about interior quality and shell condition, not size. Size is a separate label.

7. The float test, explained

FSIS addresses the old kitchen trick of dropping an egg in water. An egg floats when its air cell has grown large enough to keep it buoyant, which means the egg is older and lower in quality, but it may still be perfectly safe. FSIS's recommendation is to crack it into a bowl and check for an off odor or unusual appearance. A spoiled egg has an unpleasant smell when you open it, raw or cooked.

FSIS also explains a harmless color change: a green ring around a hard-cooked yolk usually comes from overcooking, or from high iron in the cooking water, and is safe to eat.

8. Key takeaways

• Do not wash eggs at home; FSIS says wash water can be drawn into the egg through the shell's pores, and graded eggs were already washed and sanitized.
• Store eggs at 40°F or below, in their carton, in the coldest part of the refrigerator rather than the door, and do not leave them out more than 2 hours.
• Use raw shell eggs within 3 weeks for best quality, hard-cooked eggs within 1 week, and frozen beaten eggs within 1 year.
• On USDA-graded cartons, expiration-type dates are at most 30 days after packing and "Best before" dates at most 45 days.
• A floating egg is old, not necessarily unsafe; crack it into a bowl and check the smell and look.