Opened Greek yogurt is generally good for about 5 to 7 days when stored properly in the refrigerator at or below 40°F (4°C)

. Some sources suggest it can last up to 10 to 14 days, especially due to its thick, strained consistency, but the safest guideline is within one week after opening

. Key factors for shelf life after opening:

• Keep the yogurt refrigerated consistently at or below 40°F (4°C).
• Use clean utensils to avoid contamination.
• Store in an airtight container or tightly sealed original packaging to minimize exposure to air.
• Avoid temperature fluctuations by placing it on a stable shelf away from the fridge door.

Signs that Greek yogurt has spoiled and should be discarded:

• Sour or off-putting smell
• Watery, curdled, or changed texture
• Visible mold or discoloration
• Unpleasant or unusually sour taste

If any of these signs appear, it is best to throw the yogurt out to avoid foodborne illness

. In summary, for safety and best quality, consume opened Greek yogurt within 5 to 7 days, store it properly refrigerated, and check for spoilage signs before eating.