How To Tell If Your Eggs Are Bad By The Float Method

To start, it's important to distinguish between an aged egg, a spoiled egg, and one infected with salmonella. While an aged egg may lack the freshness of a newly laid one, it's generally safe to eat despite the potentially altered taste.

A spoiled egg, on the other hand, emits a pungent, sulfuric smell due to common bacterial contamination, causing mild digestive upset if consumed. The most concerning is salmonella, a pathogenic bacterium found in some eggs, which can lead to severe illness if ingested.

Let's examine how an egg can become contaminated and learn how to determine if it's safe to consume.

Spoilage

Over time, foods stored in the fridge can spoil without necessarily becoming a health hazard. Take milk, for instance: pasteurized milk remains safe to drink, but if it's left in the fridge too long, it will start to smell, taste, and look unpleasant. The same principle applies to eggs.

The best way to determine if an egg has gone bad is by using your senses. If an egg looks or smells off compared to how it usually does, it might indicate the presence of spoilage bacteria.

Salmonella

Eating an older egg is unlikely to cause food poisoning, but it probably won’t taste very good. The real risk comes from salmonella bacteria, which cannot be detected by taste, smell, or appearance. Salmonella is only visible under a microscope, so the average person cannot tell if their egg is infected.

Fortunately, only about three out of every 10,000 eggs might contain salmonella, making the likelihood of contamination quite low. To mitigate the risk, you can take precautions to prevent bacterial growth.

Cooking an egg with salmonella to at least 150°F will kill the bacteria, so even a contaminated egg can be safely used in baking or other dishes where the egg is thoroughly cooked (i.e., no runny yolks).

Testing eggs in water is a common and simple method used to determine their freshness. Eggs have a unique structure that changes over time, primarily due to the air cell inside them growing larger as they age. This change in buoyancy is what allows the water test to work.

Fresh eggs have a smaller air cell and will typically sink in water, while older eggs with a larger air cell may float. This method is popular because it provides a quick and visual way to assess whether an egg is still good to use.

The Float Method

The water test, also known as the float test, is a simple and effective method to determine the freshness of eggs. Here's a step-by-step guide to performing the float test:

• Gather Your Supplies: You’ll need a bowl or container large enough to hold the eggs you want to test. Fill the container with enough cold water to completely submerge the eggs. The water should be deep enough for the eggs to float freely.
• Prepare the Water: Ensure the water is cold, as this helps to provide a clear and accurate result. Cold water is less likely to cause any immediate temperature changes to the eggs, which could affect their buoyancy.
• Place the Eggs in the Water: Carefully place the eggs into the container of water, one at a time. Be gentle to avoid cracking the eggshells.
• Observe the Eggs:
  
  • Fresh Eggs: If the eggs are fresh, they will sink to the bottom of the container and lie flat on their sides. This is because the air cell inside a fresh egg is small.
  • Slightly Older Eggs: Eggs that are still good to eat but not as fresh will stand upright on the bottom of the container, with the narrower end pointing down and the broader end pointing up. This indicates that the air cell has grown slightly larger but the egg is still safe to consume.
  • Old Eggs: Eggs that float to the top of the water are no longer fresh. The large air cell inside the egg makes it buoyant enough to float. These eggs should be discarded, as they may not be safe to eat.

Why It Works

The float test is based on the principle that as eggs age, the moisture inside them evaporates through the porous shell, and air replaces the lost moisture.

This increases the size of the air cell inside the egg, making it more buoyant. Fresh eggs have a smaller air cell and will sink, while older eggs with a larger air cell will float.

Is the Float Method Accurate

The float method is reliable for checking freshness but lacks scientific backing for ensuring egg safety. It's advisable to use a float-tested egg promptly because eggshells are porous and can absorb water, increasing the risk of bacterial growth (more on this shortly).

Older eggs aren't necessarily a drawback; many cooks intentionally use eggs of varying ages for specific culinary purposes. Fresher eggs are ideal for poaching or preparing sunny-side-up eggs, while older eggs are preferred for baking due to their structure.

Older egg whites are better suited for making meringue and are also advantageous for hard-boiled eggs because their shells tend to peel more easily.

Checking if an egg is bad before cracking it is crucial to ensure food safety and optimal culinary results. There are several methods people use to assess egg freshness without cracking them open, ranging from observing the shell's appearance to conducting tests like the sniff test or the shake test.

These methods help determine whether an egg is fresh and safe for consumption or if it has spoiled and should be discarded to prevent any risks of foodborne illness.

Shake Test

The Shake Test is a simple and quick method to check the freshness of an egg before cracking it open. Here’s how you can do it:

• Hold the Egg: Take the egg in your hand and hold it horizontally.
• Shake Gently: Shake the egg gently from side to side, listening for any sloshing or movement inside.
• Listen Carefully: Fresh eggs have a minimal amount of air inside, so you should hear little to no sound when you shake them. If you hear a distinct sloshing sound, it indicates that the egg has likely lost moisture through its porous shell and might not be fresh.

Check the Shell

Checking the shell of an egg is another effective method to assess its freshness before cracking it open. Here’s how you can do it:

• Inspect the Shell: Take a close look at the eggshell under good lighting. A fresh egg typically has a clean and smooth shell without cracks or blemishes.
• Check for Cracks: Run your fingers gently over the surface of the egg. Cracks or fissures in the shell can indicate that the egg is older or may have been mishandled, potentially allowing bacteria to enter.
• Look for Stains or Discoloration: Fresh eggs usually have a consistent color across the shell. Stains, spots, or discoloration can suggest that the egg is older or has been exposed to contaminants.
• Assess the Texture: The shell of a fresh egg should feel slightly chalky and not excessively smooth or slippery. If it feels unusually smooth or slimy, it might be a sign of spoilage.

Sniff Test

This is a straightforward method to determine the freshness of an egg by smelling it before cracking it open. Here’s how you can perform the Sniff Test:

• Hold the Egg: Take the egg in your hand and hold it close to your nose.
• Sniff Carefully: Gently sniff the eggshell. A fresh egg typically has little to no odor at all or may have a slight, neutral smell.
• Detect Any Odors: If the egg gives off a strong or unpleasant sulfur-like odor, it likely indicates that the egg is no longer fresh. This smell can be quite distinct and is a sign that the egg has begun to decompose.
• Consider Temperature: Room temperature can sometimes amplify odors, so it's best to perform this test at normal room temperature rather than straight from the refrigerator.
• Combine with Other Tests: While the Sniff Test is effective, it's beneficial to use it in conjunction with other methods like checking the shell for cracks or performing the Float Test.

Expiration Date

Checking the expiration date or the "sell-by" date on the egg carton is another reliable method to determine if an egg is still good. Here’s how you can use this method effectively:

• Inspect the Carton: Look for the expiration date or the "sell-by" date printed on the egg carton. This date indicates the last day by which the eggs should be sold or consumed for best quality.
• Note the Timeline: Eggs are typically safe to consume several weeks beyond the sell-by date if they have been properly stored in the refrigerator. However, fresher eggs are generally better for recipes requiring a high-quality egg taste.
• Past the date: The eggs may still be good, but further testing with the methods above is recommended.

Various methods, such as assessing odor, color, texture, and the appearance of the egg white and yolk, help identify signs of spoilage. These indicators help cooks and consumers make informed decisions about the freshness and suitability of cracked eggs for consumption.

Appearance

This is a visual method used to assess the freshness of an egg after cracking it open. Here’s how you can determine if an egg is bad based on its appearance:

• Observe the Egg White (Albumen): Fresh egg whites are clear and slightly viscous. If the egg white appears cloudy, discolored or has a pinkish hue, it may indicate spoilage or bacterial growth.
• Inspect the Egg Yolk: A fresh egg yolk is typically round and sits high on top of the egg white. A bad egg yolk may appear flattened, runny, or have an unusual texture, such as being lumpy or gelatinous.

Smell

• Sniff Carefully: Take a gentle sniff of the egg contents. A fresh egg typically has little to no odor.
• Detect Any Odors: If the egg emits a strong or unpleasant sulfur-like smell, similar to that of rotten eggs, it indicates that the egg has gone bad. This smell is distinct and often immediate upon cracking.
• Consider Room Temperature: The smell test is more effective at room temperature rather than directly from the refrigerator, as colder temperatures can sometimes suppress odors.

Texture

• Examine the Egg White: Fresh egg whites are typically clear, thick, and have a gel-like consistency. When you touch or gently stir the egg white, it should remain firm and not spread out excessively. If the egg white is runny, watery, or has a slimy texture, it may be a sign that the egg is old or spoiled.
• Inspect the Egg Yolk: The yolk of a fresh egg should be firm and slightly domed. If the yolk is flat, breaks easily, or has an unusual texture (such as being overly soft or gelatinous), it could be a sign that the egg is no longer fresh.
• Check for Clotting or Gelatinous Texture: If you notice any clots or a gelatinous texture in the egg white or yolk, it’s a clear sign that the egg has deteriorated.
• Feel for Sliminess: When handling the egg, if the contents feel unusually slimy or sticky, this is another indication of spoilage.

You can consume eggs past their expiration date, but it's important to check for spoilage first. The USDA oversees use-by, best-by, expiration, and sell-by dates (often used interchangeably), but these dates aren't always accurate. Instead, check the “pack date,” which includes a numerical code on the carton.

The last three digits represent the Julian date, where each day of the year is numbered from 001 to 365 (e.g., January 1 is 001). If stored correctly, eggs are typically safe for four to five weeks from this date. As a precaution, it's advisable to follow the ‘best-by’ recommendation, usually around 30 days from the packaging date.

After the indicated date, inspect and use the remaining eggs promptly to avoid any decline in quality.

The shelf life of eggs varies depending on how they are stored and their freshness when purchased. Here are some general guidelines:

Refrigerated Eggs

• In the Shell: Fresh, uncooked eggs can typically last for about 4 to 5 weeks beyond the pack date or about 3 weeks beyond the sell-by date.
• Out of the Shell: Once cracked open, raw egg whites and yolks should be used within 2 to 4 days if stored properly in the refrigerator.

Frozen Eggs

• Raw Eggs: Whole eggs (including mixed whites and yolks) can be frozen for up to 1 year. Similarly, separated egg whites and yolks can also be frozen for the same duration, though yolks may benefit from being mixed with salt or sugar to prevent them from becoming gelatinous upon thawing. For optimal freshness, it's generally recommended to use frozen eggs within 4 months.

Cooked Eggs

• Hard-Boiled Eggs: These can last for up to 1 week in the refrigerator.
• Other Cooked Eggs: Such as scrambled or fried eggs, typically last for 3 to 4 days in the refrigerator.

The best way to store eggs is in the refrigerator at a temperature between 35 and 40 degrees Fahrenheit (1.7 to 4.4 degrees Celsius). Storing them in their original carton helps maintain freshness and quality by protecting the eggs from absorbing odors and flavors from other foods in the refrigerator.

Avoid placing eggs in the refrigerator door, where temperatures can fluctuate frequently due to opening and closing. Consistently storing eggs at a stable temperature helps prolong their shelf life, ensuring they remain safe and high-quality for longer.

It’s also essential to check the expiration or sell-by date on the carton and use eggs within a reasonable timeframe to enjoy them at their best.