Eggs are a staple in most kitchens, and in this alpha-gal friendly household, we go through more than most. No matter how you crack it, knowing how to tell if an egg is rotten is crucial for your recipes—and your health. Fortunately, there are simple ways to check if an egg has gone bad, and you don’t need a culinary degree to figure it out.
The information provided on this site is based on my personal experience living with alpha-gal syndrome. I consistently cite and link to expert sources, but nothing published on this site should be perceived as medical advice.
Alpha-gal sensitivities vary by person. You should understand your dietary restrictions, making any adjustments needed, and directing any questions to your physician.
In this guide, I’ll walk you through how to tell if an egg is rotten. From the classic water test to expert tips on what to look for when inspecting an egg, there are tried-and-true methods for checking egg freshness will help you avoid the unpleasant surprise of a rotten egg ruining your dish.
In This Article
Does It Smell Like Trouble?
One of the easiest ways to spot a rotten egg is by its smell. If your kitchen suddenly smells like a middle school science project gone horribly wrong — or like Satan himself dropped by for brunch — it’s time to toss the egg. I’m talking about an unmistakably pungent, sulfuric odor that’s hard to ignore.
If you notice this smell when you crack one, it’s a clear sign the egg has gone bad. That said, smell alone isn’t a foolproof indicator, as some rotten eggs may not have a strong odor. That’s where these other egg checks come in handy.
Inspect the Appearance
Rotten eggs may have a cloudy or discolored yolk, and the white might be watery instead of firm. In some cases, the eggshell itself may appear discolored, slimy, or sticky. These visual cues give you a chance to catch the culprit before it makes its way into your favorite cookie batter.
What Do the Dates Say?
In the United States, eggs are often labeled with either a “sell by” or an expiration date. Check your carton of eggs for a sell-by, expiration, or pack date.
- A sell-by date indicates how long a store should offer eggs for sale, typically no more than 30 days after packing.
- An expiration date refers to the period after which eggs are considered less than fresh, although they might still be safe to eat.
- Pack dates are another clue and represent the day the eggs were packed, using a three-digit code for the calendar day of the year. For example, January 1 is 001 and December 31 is 365.
Remember: These dates are guidelines for peak quality, not safety. Eggs stored in their original carton and kept in the fridge will often outlast the printed date, so don’t toss them without checking for other signs of freshness first.
The Float Test
One way to determine if an egg is past its prime is the float test. This test is simple and easy to do at home, so you can quickly check an egg before using it in something like a hashbrown casserole.
To perform this simple test:
- Fill a bowl with cold water.
- Gently place the egg in the bowl of water.
What to look for:
- If it sinks and lies flat, it’s fresh.
- If it stands upright on one end, it’s still safe to eat but less fresh.
- If it floats to the top, it’s likely spoiled and should be discarded.
Sage Advice: Eggs that stand upright at the bottom are ideal for making hard-boiled eggs. Their larger air pocket ensures the yolk stays centered—perfect for deviled eggs.
It’s important to note that the float test is not foolproof. Some rotten eggs may still sink to the bottom of the bowl, and some fresh eggs may float. When in doubt, use your eyes and nose as a backup plan.
“Checking if an egg is rotten before cooking is essential. Rotten eggs can contain harmful bacteria like Salmonella, which can cause foodborne illness. Verifying the freshness of your eggs helps prevent health hazards and any symptoms associated with consuming contaminated eggs.”
The Shake Test
Hold the egg up to your ear and shake it, listening for a sloshing sound. As the egg ages, moisture and carbon dioxide escape through the shell. This creates a larger air pocket inside, giving the contents more room to move around.
What to look for:
- A fresh egg should not make much, if any, sound when you shake it.
- A sloshing egg only indicates that the egg is older. It does not automatically mean that the egg is unsafe for consumption.
Shine a Light on Freshness
Known as the candling test, this traditional method requires a bright light. For this test, hold the egg up to a light source, such as a flashlight. Look for any irregularities inside the shell. A fresh egg will have a distinct yolk and thick, clear egg white. Rotten eggs may appear cloudy or show signs of dark spots.
It’s important to note that not all abnormalities found during the candling test indicate that the egg is rotten. Blood spots might look alarming, but they’re perfectly harmless and don’t affect the egg’s quality. If you notice a foul odor or slimy texture, however, it’s best to dispose of the egg.
The Crack Test
If you want a quick, no-frills way to determine whether an egg is still good, the crack test is your best bet. This tried-and-true method lets you use your senses—sight, smell, and even touch—to decide if an egg is safe to use.
- Gently tap the egg on a hard surface and open it into a bowl. If you’re cracking multiple eggs, crack them one at a time into a separate bowl to avoid contaminating the rest of your ingredients.
- Does it smell off? A rotten egg will have a strong, sulfuric odor that’s impossible to miss.
- Inspect the yolk and white. A fresh egg will have a plump, vibrant yolk surrounded by a thick, gel-like white. A bad egg will have a runny white and a flat, weak yolk.
Sage Advice: Crack each egg into a separate bowl before adding it to your recipe. This way, if you do encounter a bad egg, it won’t ruin your whole dish.
Rotten Egg? Not in Your Kitchen!
Spotting a rotten egg is an essential skill if you want to ensure the safety and quality of your food. By following the steps outlined in this article, you can easily identify rotten eggs and avoid eating them.
Portions of this article originally appeared on Food Drink Life.
