Eggs
In the US, eggs stay safe roughly 3 to 5 weeks in the refrigerator after you buy them — well past the Sell-By date printed on the carton.
Why refrigerate?
A freshly laid egg comes with its own defence: a microscopically thin layer on the shell called the cuticle, which seals the thousands of tiny pores and keeps bacteria out. In the United States, eggs are washed and sanitised before sale, and that washing removes the cuticle. Without it the porous shell is more vulnerable, so the FDA requires eggs to be kept refrigerated at or below 40 °F (4 °C) from the store onward.
Kept cold from the start, eggs stay safe for roughly three to five weeks. The Sell-By date printed on the carton is a store-rotation date, not a safety deadline — it simply tells the retailer how long to display them. What matters far more is an unbroken cold chain: an egg that warms up and cools down repeatedly forms condensation that helps bacteria spread, so avoid leaving eggs out for more than two hours.
Around a third of the food produced worldwide is thrown away, and misread dates are a major reason. Eggs are among the items discarded soonest — often while they are still perfectly good. Knowing the float test turns a guess into a two-second check and keeps good eggs out of the bin.
Source: FAO / USDAHow do I know?
Whether an egg is still good comes down to your senses more than the printed date. Three quick checks tell you almost everything:
Cracks, a slimy film or a musty smell are warning signs. Do not use such eggs raw.
A fresh egg smells neutral. A sulphur or sour smell means it is off — discard it. Smell is the most reliable test.
A watery, runny white and a flat yolk point to an older egg. It is usually still fine if you cook it thoroughly.
Check it yourself: the float test
The simplest freshness test costs nothing and takes seconds. Place the egg in a glass of cold water. Inside every egg is an air cell that grows with age as moisture escapes through the pores. The bigger the air cell, the more the egg floats — and that tells you the status:
Fresh — safe to use any way.
Older — use soon and cook it thoroughly.
Do not use — throw it out.
Shelf life at a glance
How long an egg keeps depends heavily on how it is prepared and stored. This table sums up the most common cases:
| State | Shelf life |
|---|---|
| Raw, in shell (refrigerated) | 3–5 weeks |
| Raw yolks/whites (refrigerated) | 2–4 days |
| Hard-boiled, refrigerated | about 1 week |
| Left out over 2 hours | discard |
| Frozen (out of shell, beaten) | about 1 year |
Store it right
The right storage keeps eggs fresh for weeks longer. Four habits make the biggest difference:
Keep at or below 40 °F (4 °C) — refrigerate as soon as you get home and keep the cold chain unbroken.
Leave them in the carton — it protects them and keeps strong odours out of the porous shell.
Not in the door — the temperature swings every time it opens; use an inner shelf.
Do not wash — US eggs are already cleaned; re-washing adds moisture and pushes bacteria through the shell.
Common myths
Stubborn myths send plenty of good eggs to the trash. Three come up again and again:
Not so — Sell-By is for the store. Kept cold, eggs are usually good for three to five weeks after purchase.
Brown or white only reflects the breed of hen — it says nothing about freshness or quality.
Not US eggs — they are washed at the plant, and re-washing removes protection and adds moisture.
The three-digit Julian date stamped next to the plant code on a US carton is the pack date (001 = 1 Jan, 365 = 31 Dec) — a more useful freshness guide than the Sell-By date. Eggs are typically packed within a week of being laid.