Cottage cheese typically lasts about 7 days (one week) after opening when properly stored in the refrigerator. The U.S. Department of Health and Human Services recommends consuming opened cottage cheese within one week for safety

. Some sources suggest it can last up to 10 days if kept well refrigerated, but one week is a safer guideline

. To keep cottage cheese fresh longer, store it in an airtight container in the coldest part of the fridge (not the door), and avoid temperature fluctuations

. A useful tip to extend its shelf life is to store the container upside down, which creates a vacuum effect that slows bacterial growth

. Signs that cottage cheese has gone bad include:

• Sour smell or taste
• Mold growth (discard immediately)
• Watery separation with uneven curds and whey

If it smells or tastes off, it should not be eaten

. Always use clean utensils to avoid contamination and reseal the container tightly after use

. In summary, after opening, cottage cheese should be consumed within about 7 days, stored properly in the fridge, and discarded if it shows signs of spoilage