How can you tell if sour cream has gone off?

Smell:

* The most obvious sign: Sour cream that's gone bad will have a strong, unpleasant sour smell. This will be much stronger than its normal tangy aroma.

Appearance:

* Change in texture: It may become thin and watery, or thick and lumpy.

* Mold: Visible mold growth on the surface is a clear indication that the sour cream has spoiled.

Taste:

* If in doubt, taste a tiny amount: If it tastes bitter, overly sour, or just off, it's best to discard it.

Other factors to consider:

* The expiration date: While not always accurate, it's a good guideline.

* Storage conditions: Sour cream should be stored in the refrigerator, ideally in the coldest part. Keep it tightly sealed.

* How long has it been open? Once opened, sour cream usually lasts for 1-2 weeks in the fridge.

When in doubt, throw it out! Food poisoning is no fun, and it's better to be safe than sorry.