Do Eggs Go Bad in the Refrigerator? Understanding Egg Freshness and Safety
Eggs can go bad in the refrigerator, but if stored properly and kept at a consistently cold temperature, they can remain safe to eat for several weeks beyond their sell-by date.
The Incredible, Edible Egg: Background and Benefits
Eggs are nutritional powerhouses, packed with protein, vitamins, and minerals. They’re a staple in many diets, versatile for cooking, and relatively affordable. From scrambled eggs for breakfast to baking ingredients in cakes, eggs play a crucial role in countless culinary creations. Understanding how to store them properly is essential to maximizing their freshness and preventing foodborne illness. Beyond their deliciousness, eggs offer significant health benefits:
- High-quality protein: Essential for building and repairing tissues.
- Rich in vitamins and minerals: Including vitamin D, B12, choline, and selenium.
- May improve cholesterol levels: Despite previous misconceptions, studies show eggs can raise “good” HDL cholesterol.
- Promotes satiety: Helping you feel fuller for longer.
How Eggs Stay Fresh in the Refrigerator: The Science Behind It
Refrigeration significantly slows down the growth of bacteria and enzymes that cause eggs to spoil. The cold temperature prevents these microorganisms from multiplying to levels that would make the eggs unsafe to eat or change their texture and flavor. The egg’s shell acts as a natural barrier, but it’s porous, allowing some air and moisture to pass through. This is why proper storage is critical.
- Temperature: Maintaining a consistent temperature of 40°F (4°C) or below is crucial.
- Humidity: The refrigerator’s humidity helps prevent the eggs from drying out.
- Shell Protection: The shell is a natural barrier against bacteria, but it’s not impenetrable.
Proper Egg Storage Techniques: Maximizing Shelf Life
Storing eggs correctly in the refrigerator can dramatically extend their shelf life. Follow these guidelines for optimal freshness:
- Keep eggs in their original carton: The carton protects the eggs from absorbing odors and flavors from other foods in the refrigerator. It also helps to maintain moisture and prevents the eggs from rolling around and potentially cracking.
- Store eggs in the coldest part of the refrigerator: Avoid storing eggs in the refrigerator door, as the temperature fluctuates more in that location. The main body of the refrigerator provides a more consistent temperature.
- Use eggs within the “sell-by” date: While eggs can be safe to eat after the “sell-by” date, their quality will decline. For best results, use them as soon as possible.
- Don’t wash eggs before storing: Washing eggs removes the protective bloom (a natural coating) on the shell, making them more vulnerable to bacterial contamination. Commercial eggs are typically washed and treated to remove the bloom, and then coated with a mineral oil to restore some of the protection.
Identifying Spoiled Eggs: Signs to Watch Out For
Even with proper refrigeration, eggs will eventually go bad. Here are some signs that indicate an egg is no longer safe to eat:
- Offensive odor: A rotten egg will have a distinct sulfurous or putrid smell, even before cracking it open.
- Abnormal appearance: Check for cracks or slime on the shell.
- Floating test: Place the egg in a bowl of water. If it sinks, it’s likely fresh. If it floats, it’s likely spoiled. This is because as an egg ages, air enters through the porous shell, increasing the buoyancy.
- Discolored yolk or white: If the yolk or white appears green, pink, or black, discard the egg immediately.
Common Mistakes in Egg Storage: Avoiding Foodborne Illness
Many common mistakes can shorten the lifespan of eggs and increase the risk of foodborne illness. Avoid these errors:
- Storing eggs in the refrigerator door: Fluctuating temperatures can compromise egg quality.
- Washing eggs before storing: Removing the protective bloom increases the risk of contamination.
- Leaving eggs at room temperature for extended periods: Bacteria can multiply rapidly at room temperature.
- Not using eggs by the “sell-by” date: While not necessarily spoiled, quality declines after this date.
Egg Freshness Timeline: How Long Do They Really Last?
This table provides a general guideline for egg freshness, assuming proper storage:
| Storage Location | Estimated Shelf Life | Notes |
|---|---|---|
| Refrigerator (in carton) | 3-5 weeks beyond the “sell-by” date | Maintain consistent temperature; store in the main body of the refrigerator. |
| Hard-boiled Eggs (refrigerated) | Up to 1 week | Store in the refrigerator immediately after cooking. |
| Egg Whites or Yolks (refrigerated) | Up to 4 days | Store in an airtight container. |
| Frozen Eggs (whites or yolks) | Up to 1 year | Never freeze whole eggs in their shells. Crack them open, separate whites and yolks (or lightly beat them together), and freeze. |
Frequently Asked Questions (FAQs)
What does the “sell-by” date mean on the egg carton?
The “sell-by” date is not an expiration date. It indicates the date by which the store should sell the eggs. Eggs can still be safe to eat for several weeks after this date if stored properly.
Can I freeze eggs?
Yes, but only if they are removed from their shells. Whole eggs in their shells will expand and crack when frozen. Separate the yolks and whites, or lightly beat them together, and freeze in airtight containers.
Is it safe to eat raw eggs?
Eating raw or undercooked eggs carries a risk of Salmonella contamination. This risk is lower with pasteurized eggs, but still present. Pregnant women, young children, the elderly, and people with weakened immune systems should avoid eating raw or undercooked eggs.
What is the “float test” and how accurate is it?
The “float test” involves placing an egg in a bowl of water. If it sinks, it’s likely fresh. If it floats, it’s likely spoiled. This test is relatively accurate because as an egg ages, air enters through the porous shell, increasing its buoyancy.
How can I tell if a cracked egg is safe to eat?
If you find a cracked egg, discard it immediately. Cracks can allow bacteria to enter the egg, increasing the risk of contamination. Even if the egg looks and smells normal, it’s best to err on the side of caution.
Are brown eggs healthier than white eggs?
The color of the eggshell does not affect the nutritional value of the egg. The breed of hen determines the color of the shell.
What is the white stringy thing in my egg? Is it safe to eat?
The white stringy thing is called the chalaza. It anchors the yolk in the center of the egg. It is perfectly safe to eat and is a sign of freshness.
Why do some eggs have double yolks?
Double-yolked eggs are more common in young hens that are just starting to lay eggs. They are caused by a slight irregularity in the hen’s ovulation cycle. They are safe to eat.
What does “pasteurized” mean when it comes to eggs?
Pasteurization is a process that heats eggs to a temperature that kills Salmonella bacteria without cooking the egg. Pasteurized eggs are considered safer to eat raw or undercooked.
How long can hard-boiled eggs stay in the refrigerator?
Hard-boiled eggs can be stored in the refrigerator for up to one week. They should be stored in their shells to help retain moisture.
Can I eat eggs that are past the “sell-by” date if they look and smell fine?
While eggs may still be safe to eat past the “sell-by” date, their quality will decline. It’s best to use them as soon as possible for optimal flavor and texture.
What’s the best way to cook eggs to kill Salmonella bacteria?
To kill Salmonella bacteria, eggs should be cooked to an internal temperature of 160°F (71°C). This means cooking eggs until the whites are firm and the yolks are beginning to thicken. For scrambled eggs, cook until they are no longer runny.