Sour cream typically lasts about 7 to 10 days after opening when stored properly in the refrigerator

. However, according to the USDA and multiple food safety sources, sour cream can remain safe and good to use for up to three weeks after opening, provided it is kept refrigerated at or below 40°F (4°C)

. Key points for storage and safety:

• Keep sour cream continuously refrigerated at or below 40°F.
• Avoid contamination by using clean utensils.
• Signs of spoilage include mold growth, off smells, discoloration (yellow or green), and a slimy texture. If any of these appear, discard the sour cream immediately

• Separation of liquid (whey) on the surface is normal and not a spoilage sign; it can be stirred back in or drained off

• An effective storage tip is to store the container upside down to create a vacuum that inhibits bacterial growth, potentially extending shelf life

In summary, sour cream generally lasts 1 to 3 weeks after opening when refrigerated properly, but always rely on sensory checks (smell, appearance) to ensure it is safe to consume.