Which is a common sign of spoiled dairy products?

• A. Fresh aroma.
• B. Sour smell, off taste, curdling
• C. Clear liquid with no odor.
• D. Bright white color.

Answer: (B)

Dairy spoilage is driven by bacterial growth that changes smell, taste, and texture. When dairy goes bad, it often develops a sour odor from lactic acid and the taste becomes off or sour as acidity rises. You may also notice curdling, where proteins clump and separate from the liquid. Fresh dairy should have a clean, mild aroma, a smooth texture, and an even color. A clear liquid with no odor can be normal separation in some products and isn’t a reliable spoilage sign, and a bright white color usually indicates freshness. So, the strongest cue that a dairy product has spoiled is a combination of sour smell, off taste, and curdling. If you notice these, it’s best to discard the product to avoid foodborne illness.