How To Tell If An Egg Has Gone Bad

Eggs are a versatile and nutritious food, but like all perishable items, they have a shelf life. Determining whether an egg is still fresh or has gone bad can be tricky, especially since the outer appearance of an egg doesn’t always reveal its internal condition. This guide will provide you with multiple methods to assess the freshness of an egg, ensuring that you enjoy your eggs safely and without waste.

The Float Test: A Simple and Reliable Method

One of the most common and effective ways to check if an egg is still good is the float test. This method takes advantage of the fact that as eggs age, the air cell inside them enlarges, causing the egg to become more buoyant.

How to Perform the Float Test:

1. Fill a bowl with cold water.
2. Gently place the egg into the water.
   • Fresh eggs will sink to the bottom and lie flat on their sides.
   • Eggs that are still safe but not at their freshest may stand upright on the bottom of the bowl.
   • Bad eggs will float to the surface, indicating that they are no longer safe to eat.

This test works because, over time, the egg’s contents shrink as moisture evaporates through the shell, and the air pocket grows larger, making the egg buoyant enough to float.

The Sniff Test: Trust Your Nose

The sniff test is a straightforward way to determine if an egg has spoiled. Fresh eggs have a neutral smell, but when they go bad, they emit a distinctive sulfuric odor.

How to Perform the Sniff Test:

1. Crack the egg into a clean bowl.
2. Immediately smell the egg.
   • Fresh eggs will have no noticeable odor.
   • Spoiled eggs will have a foul, rotten smell.

If you detect any off-putting smell, it’s best to discard the egg, as it could make you sick.

Visual Inspection: Check for Unusual Appearances

Sometimes, you can visually inspect an egg to check for signs of spoilage.

What to Look For:

1. Shell: Examine the shell for cracks, sliminess, or powdery spots, which could indicate bacterial or mold contamination. Discard any eggs with these signs.
2. Egg white and yolk: After cracking the egg, inspect the egg white and yolk.
   • Fresh eggs have a thick, slightly cloudy white and a firm, well-rounded yolk.
   • Older eggs will have a thinner, runnier white, and the yolk may appear flattened or more spread out.
   • Spoiled eggs may have pink, green, or iridescent egg whites, which indicate bacterial contamination and should be discarded immediately.

The Shake Test: Listen to the Egg

The shake test is a less common but still useful method to assess an egg’s freshness.

How to Perform the Shake Test:

1. Hold the egg up to your ear.
2. Gently shake it back and forth.
   • Fresh eggs will not make much noise because the contents are still firm and cohesive.
   • Old or bad eggs may produce a sloshing sound, indicating that the egg white has thinned and the egg is no longer fresh.

While this test isn’t as reliable as the float or sniff tests, it can be a quick way to make an initial assessment.

Check the Expiration Date: Use It as a Guideline

Egg cartons come with a sell-by or expiration date, which can be a helpful guide in determining the freshness of the eggs. However, eggs can still be good for a while after the expiration date has passed, especially if they have been stored properly in the refrigerator.

General Guidelines:

• Refrigerated eggs: These can remain safe to eat for 3-5 weeks beyond the sell-by date. However, it’s always good practice to perform the float or sniff tests if you’re unsure.
• Room temperature eggs: If stored at room temperature, eggs should be used more quickly, ideally within a week or two, as they age faster outside the fridge.

The Candling Method: For the Curious and Committed

Candling is a technique used by egg producers and enthusiasts to assess the quality of an egg by observing it under a bright light.

How to Perform Candling:

1. In a dark room, hold the egg up to a bright light source.
2. Rotate the egg slowly to observe its contents.
   • Fresh eggs will show a small air cell, and the egg white and yolk will appear compact.
   • Older eggs will show a larger air cell, and the contents may be more spread out.

While candling is more commonly used to check for fertility in hatching eggs, it can also reveal the internal condition of an egg, helping you determine its freshness.

Conclusion: Multiple Ways to Ensure Egg Safety

Understanding how to tell if an egg has gone bad is essential for anyone who uses eggs regularly. By using methods like the float test, sniff test, and visual inspection, you can confidently assess the freshness of your eggs. Remember, when in doubt, it’s safer to discard an egg than risk consuming one that could cause foodborne illness. Following these guidelines will help you enjoy your eggs at their best while minimizing waste.