How can you tell if a block of blue cheese, that’s been stored in the refrigerator (wrapped in its original packaging and then an additional layer of plastic wrap) for a few weeks, has gone bad? I’m concerned about signs beyond just the appearance of mold, as blue cheese inherently has mold. Specifically, are there changes in texture, smell, or color that would definitively indicate spoilage and make it unsafe to eat, even if there’s no visible new mold growth outside the blue veins that are characteristic of the cheese? What are the key indicators to look for to differentiate between normal aging/development of the cheese and actual spoilage that could make me sick?
Answer
Here’s how you can tell if blue cheese has gone bad:
Visual Signs:
- Mold Overgrowth: Blue cheese is characterized by its blue or green veins of mold. However, excessive or unusual mold growth beyond the typical veining is a bad sign. Look for fuzzy, brightly colored (other than blue/green), or significantly expanded mold patches.
- Discoloration: Noticeable discoloration beyond the characteristic blue or green veining, such as a brownish or yellowish hue, may indicate spoilage.
- Slimy Texture: A slimy or sticky film on the surface of the cheese is a strong indicator of bacterial growth and spoilage.
- Dry, Hard Texture: If the cheese has become excessively dry, hard, and cracked, especially around the edges, it has likely lost its moisture and flavor due to prolonged exposure or improper storage. While not necessarily unsafe to eat (unless other signs of spoilage are present), the quality will be significantly diminished.
Smell:
- Ammonia-Like Odor: A pungent, ammonia-like smell is a common sign of protein breakdown and spoilage.
- Overly Strong, Unpleasant Odor: Blue cheese naturally has a strong, pungent aroma. However, if the smell becomes overwhelmingly offensive or noticeably different (e.g., sour, rancid), it’s best to discard it.
Taste:
- Sour or Rancid Taste: If the cheese has a sour, rancid, or otherwise "off" taste, it has likely spoiled. Even a small taste can tell you a lot.
- Unusual Metallic Taste: An unusual metallic taste can sometimes indicate spoilage.
Other Considerations:
- Expiration Date: Check the "sell-by" or "use-by" date on the packaging. While blue cheese can sometimes be safe to eat past this date if stored properly, it’s a good starting point. If the date is long past, examine the cheese carefully for other signs of spoilage.
- Storage Conditions: Blue cheese should be stored properly in the refrigerator, wrapped tightly in plastic wrap or aluminum foil, or stored in an airtight container to prevent drying out and absorbing odors from other foods. Improper storage accelerates spoilage.
- Presence of Pests: The presence of mold mites indicates the cheese is not stored well and should be thrown away.
What to do if you suspect spoilage:
When in doubt, it is always best to err on the side of caution and discard the cheese. Food poisoning is not worth the risk.