Noticed black spots inside an egg? Learn what can cause this to happen during storage and if it's a sign that the egg has gone bad.
1 Answer
Black spots in eggs stored in cold storage are usually caused by mold or bacteria growth, often *Pseudomonas*, which thrive in humid, cold environments and penetrate the eggshell. These spots are generally an indication of spoilage.
Detailed Explanation:
Eggs are porous, meaning their shells allow air and moisture to pass through. When eggs are stored in cold, humid environments, such as a refrigerator, moisture can condense on the shell. This moisture, combined with the cool temperature, creates an ideal environment for the growth of certain types of bacteria and molds, most commonly *Pseudomonas* species.
*Pseudomonas* bacteria can penetrate the eggshell and grow inside the egg, leading to the formation of black or greenish-black spots. These spots are a clear sign of bacterial contamination and indicate that the egg is no longer safe to eat. The bacteria produce pigments that cause the discoloration. While some molds might also cause spots, bacterial contamination is the more common culprit.
Proper storage is crucial to prevent this. Eggs should be stored in their original carton in the coldest part of the refrigerator, away from foods with strong odors that they can absorb. Maintaining a consistent temperature and avoiding temperature fluctuations will also help to inhibit bacterial growth.
Pro Tip:
Always inspect eggs for cracks or dirt before storing them. Cracks provide easy entry points for bacteria, and dirt can harbor microorganisms that accelerate spoilage. Discard any eggs with visible cracks or excessive dirt.