The first indication of bad cottage cheese is its appearance. The most apparent sign is mold. Unless you’re a doctor, you shouldn’t even taste the product. If you notice a sour smell or a moldy appearance, you should throw it away. A week’s cottage supply should be consumed within 48 hours of purchase. If you can’t find the cheese’s flavor, it may be expired.
If the cottage cheese is chunky or has a water layer on top, it’s probably not ready for eating. If it has a strange smell, you’ve found a spoiled product.