How to Know if Eggs are Bad: A Comprehensive Guide
Eggs are a staple in many households, and they're an excellent source of protein, vitamins, and minerals. However, if eggs are not stored properly, they can spoil quickly, leading to foodborne illnesses. Knowing how to determine if an egg is bad is crucial to ensure food safety and avoid waste. In this article, we'll explore the signs, symptoms, and methods to check if eggs are still good to eat.
Signs of Spoiled Eggs
Before we dive into the methods to check eggs, let's go over the common signs of spoiled eggs. These include:
- Cracks in the shell: If the egg has any visible cracks, it's best to err on the side of caution and discard it.
- Off smells: A sour, unpleasant odor emanating from the egg is a clear indication of spoilage.
- Slime or mold: Any visible signs of slime or mold on the egg or its contents mean the egg has gone bad.
Check the Egg's Expiration Date
Every egg has a "Sell By" or "Use By" date printed on the carton or container. While these dates aren't necessarily expiration dates, they do indicate the last day the store is allowed to sell the eggs. If the date has passed, it's still safe to use the eggs for another week or two, as long as they're stored properly. To extend the shelf life, store eggs in the refrigerator at a consistent temperature below 40°F (4°C).

Water Test: The Classic Method
The water test is a simple and reliable method to check if an egg is still good. Here's how to do it:
Fill a bowl with cold water, and gently place the egg into it. If the egg sinks to the bottom and lies flat, it's fresh. If it stands on its end or sinks but wobbles, it's nearing its expiration date. If it floats to the surface, it's spoiled.
Visual Inspection: Check for Opacity
A simple visual inspection can also reveal whether an egg is bad or not. Hold the egg up to a light source and inspect it for any signs of opacity or translucency. If the egg has become cloudy or developed a visible blood ring, it's likely gone bad.

Other Methods to Check Eggs
There are other methods to check eggs, including:
- Spin Test: Spin the egg on a flat surface. A fresh egg will spin smoothly, while a spoiled egg will wobble.
- Crack Test: Gently crack the egg into a bowl. If the egg has an off smell or appears discolored, it's best to discard it.
Best Practices for Storing Eggs
To ensure eggs stay fresh for as long as possible, follow these best practices:
- Store eggs in the refrigerator at a consistent temperature below 40°F (4°C).
- Keep eggs in their original carton or container.
- Turn eggs occasionally to prevent moisture from accumulating.