Whether or not you can eat sour yogurt depends on why it's sour. Yogurt is inherently somewhat sour due to the presence of lactic acid produced during fermentation. However, excessive sourness can indicate spoilage, which could make it unsafe to eat.
Here's a breakdown:
-
Naturally Sour Yogurt: Yogurt contains live and active cultures that convert lactose (milk sugar) into lactic acid. This lactic acid is what gives yogurt its characteristic tangy or sour flavor. This is perfectly normal and safe to eat. The sourness will vary depending on the type of yogurt and how long it has been fermenting.
-
Spoiled Yogurt: If yogurt becomes excessively sour beyond its usual tang, it could be a sign of spoilage. Other signs of spoilage include:
- Appearance: Mold growth, discoloration, separation of whey (liquid).
- Smell: A foul or unusual odor that differs from the normal yogurt smell.
- Texture: A significantly changed texture (e.g., chunky, curdled).
If you observe any of these signs along with extreme sourness, it's best to discard the yogurt. The reference text indicates that harmful microbes might have grown, leading to potential foodborne illness.
In summary:
- A mild sour taste is normal for yogurt.
- Excessive sourness combined with other signs of spoilage (mold, off smell, texture changes) indicates it's likely unsafe to eat.
- When in doubt, it's always better to err on the side of caution and throw it away.
