Eggs are a staple in many kitchens, but they’re also one of the few foods that can spoil without showing obvious signs. While eggs typically have a long shelf life, it’s important to know whether they’re still safe to eat, especially if they’ve been sitting in your fridge for a while.

In this article, we’ll cover several simple methods to tell if an egg is bad, so you can avoid foodborne illness and enjoy your eggs with peace of mind.

1. The Float Test

One of the easiest and most reliable ways to check if an egg is still good is the float test. This method helps you determine the age of the egg by observing how it behaves in water.

How to Perform the Float Test:

Fill a bowl or glass with water: Use enough water to fully submerge the egg.

Gently place the egg in the water: Make sure the egg is completely submerged.

What to Look For:

If the egg sinks and lies flat on its side: The egg is fresh and safe to eat.

If the egg sinks but stands upright or tilts slightly: The egg is still good but not as fresh. It’s best to use it soon, preferably for hard-boiling or baking.

If the egg floats to the top: The egg is bad and should be discarded. Floating eggs indicate that the air pocket inside the egg has expanded, which happens as the egg ages and moisture escapes.

Why It Works:

Eggshells are porous, allowing air to gradually seep into the egg over time. As an egg deteriorates, the air pocket inside grows larger, making the egg buoyant and causing it to float.

2. The Sniff Test

The sniff test is a quick and definitive way to tell if an egg has gone bad. Spoiled eggs have a distinct and unpleasant odor that is hard to miss.

How to Perform the Sniff Test:

Crack the egg into a bowl: If you’re unsure about the egg’s freshness, crack it into a separate bowl rather than directly into your cooking or recipe.

Smell the egg: Take a good whiff of the egg after cracking it.

What to Look For:

If the egg smells neutral or has no odor: The egg is fresh and safe to eat.

If there’s a strong, sulfur-like or rotten odor: The egg is bad, and you should discard it immediately. This odor will be unmistakable and is a clear sign that the egg has spoiled.

Why It Works:

When an egg goes bad, bacteria break down the proteins inside, producing sulfur compounds that give off the characteristic “rotten egg” smell.

3. The Visual Inspection

Another way to check if an egg is bad is by giving it a visual once-over. While eggs may not always show obvious signs of spoilage, certain visual cues can indicate that the egg is no longer fresh.

What to Look For:

Check the shell: Examine the egg for cracks, slimy residue, or powdery patches. A slimy shell may indicate the presence of bacteria, while a powdery appearance could suggest mold.

Inspect the egg white and yolk: After cracking the egg into a bowl, look at the color and texture.

Fresh eggs will have thick, slightly cloudy whites and a yolk that sits high and round.

Older eggs will have thinner, more watery whites and yolks that may appear flatter.

Bad eggs may have discolored whites or yolks, such as pink, green, or black spots, which indicate bacterial contamination or mold.

Why It Works:

Changes in the egg’s appearance, such as discoloration or abnormal textures, often signal that the egg is no longer safe to eat due to bacterial growth or spoilage.

4. The Shake Test

The shake test can also help you assess an egg’s freshness, though it’s not as reliable as the float or sniff tests. This method is quick and requires no extra tools.

How to Perform the Shake Test:

Hold the egg close to your ear.

Gently shake the egg.

What to Listen For:

If you hear little to no movement: The egg is likely fresh. Fresh eggs have a thick egg white and yolk that do not move much inside the shell.

If you hear a sloshing sound: The egg is older, and the contents have become more liquidy due to the breakdown of the egg white and yolk. This doesn’t necessarily mean the egg is bad, but it’s a sign that it’s aging.

Why It Works:

As eggs age, the yolk and egg white lose their firmness, which causes them to move around more freely inside the shell. The more liquid you hear, the older the egg is likely to be.

5. Check the Expiration Date

While expiration dates aren’t always the most reliable way to tell if an egg is bad, they can give you a general idea of the egg’s freshness.

What to Look For:

Sell-by date: This date tells retailers when the eggs should be sold by, but eggs are often still good for 3-5 weeks after this date if stored properly.

Expiration date: If the egg is past its expiration date, it’s best to test it using methods like the float or sniff test to ensure it’s still safe to eat.

Julian date: On some egg cartons, you may see a three-digit number called the Julian date, which represents the day of the year the eggs were packed. For example, 001 would be January 1st, and 365 would be December 31st. Eggs are typically good for 4-5 weeks from the Julian date.

Why It Works:

While dates on the carton can provide a rough estimate of the egg’s age, they don’t always reflect the actual freshness of the egg, especially if it’s been stored properly in the fridge.

6. Observe How the Egg Cooks

If you’ve already started cooking the egg and suspect it may have gone bad, you can often tell based on how it behaves when it hits the pan.

What to Look For:

A fresh egg: The egg white should remain firm, and the yolk should hold its shape without spreading too much.

An old or bad egg: The egg white will spread out more thinly and the yolk may break easily or flatten out. Additionally, if the egg emits a bad odor when cooking, it’s a clear sign that it has spoiled.

Why It Works:

As eggs age, the proteins in the egg white and yolk break down, causing them to lose their structure. Cooking will often reveal these changes more clearly.

Knowing how to tell if an egg is bad is an essential kitchen skill that can help you avoid foodborne illness and prevent waste. By using methods like the float test, sniff test, and visual inspection, you can easily determine whether your eggs are still fresh or if it’s time to toss them. Remember to store your eggs properly and use these techniques whenever you’re unsure of their freshness.

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Julia Jane is a home cook inspired by her mother's cooking. With the desire to share my cooking experiences with everyone, she created this website

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