Many consumers rely on the dates printed on egg cartons, which often leads to confusion and the unnecessary discarding of perfectly good eggs. While these dates provide a guideline, eggs can frequently remain safe for consumption beyond the stated period. Understanding egg dating and employing simple freshness tests can help determine an egg’s true condition.
Deciphering Egg Dating Labels
Egg cartons typically display various dates. A “Sell By” or “EXP” (expiration) date indicates the last day the store should offer the eggs for sale. This date is not a strict safety deadline; eggs can often be consumed safely for several weeks afterward. Federal regulations do not mandate expiry dates on eggs, though state laws might require “sell-by” dates.
Another date is the “Pack Date” or “Julian Date,” a three-digit code representing the day the eggs were washed, graded, and placed in the carton. Eggs stored properly in the refrigerator can remain fresh for four to five weeks beyond this pack date. The “Best By” date suggests when the eggs are at their peak quality.
Practical Tests for Egg Freshness
Beyond carton dates, several practical methods assess an egg’s freshness. The float test involves gently placing an egg in a bowl of cold water. A very fresh egg sinks to the bottom and lies flat. As an egg ages, its shell becomes more porous, allowing moisture to evaporate and an air cell inside to enlarge, increasing its buoyancy.
An egg that sinks but stands upright indicates it is older but still safe to eat, though it should be used relatively soon. If the egg floats completely, it is old and should be discarded. While the float test indicates age, it does not definitively confirm spoilage; an old egg may still be safe if other indicators are positive.
Sensory tests provide further confirmation. A visual inspection of the shell can reveal cracks or sliminess, indicating potential bacterial contamination. When cracked open, fresh egg whites are thick and do not spread much, while older eggs may have runnier whites. A fresh yolk appears rounded and firm, but an older one might be flatter. Any unusual colors like pink, green, or black spots are clear signs of spoilage.
The smell test is the most definitive for spoilage. A spoiled egg produces a strong, unpleasant, sulfur-like odor, often detectable even before cracking. If an egg emits any foul smell, it should be discarded immediately, regardless of its appearance or float test result.
Ensuring Egg Safety and Longevity
Proper storage is fundamental to maximizing egg shelf life and minimizing safety risks. Eggs should always be refrigerated promptly at 40°F (4°C) or below. Storing them in their original carton on an inside shelf, rather than the refrigerator door, helps maintain a consistent, cold temperature and prevents them from absorbing odors from other foods. The carton also protects them from physical damage.
The primary safety concern with eggs is Salmonella bacteria, which can be present inside an uncracked egg. Proper cooking eliminates this risk. Eggs and egg-containing dishes should be cooked until both the yolk and white are firm, reaching an internal temperature of 160°F (71°C). This temperature is sufficient to kill Salmonella. A foul odor remains the ultimate sign that an egg should be discarded for safety.