How to Determine Spoilage in Yogurt

Because yogurt has a longer shelf life than milk and tends to maintain the same color and texture, it can sometimes be difficult to tell if it is spoiled. Determining spoilage in yogurt requires the consumer to be observant. Both homemade and store-bought yogurt can go bad, and there are some telltale signs of spoilage in both varieties. Sealed containers of yogurt may last well past the sell-by date, but open containers of yogurt usually spoil within about a week. It's important to stay away from spoiled yogurt, as consuming it can cause digestive issues.

Things You'll Need

• Spoon

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Instructions

• 1

  Check the consistency of homemade yogurt before you transfer it to the refrigerator. If it hasn't set up properly, the yogurt is bad and needs to be disposed of. This means that the culture didn't fully convert the milk to yogurt and the dairy is now spoiled.

• 2

  Sniff the yogurt. This is a simple way to detect spoiled yogurt because it should be obvious if something is off. Normally, both homemade and store-bought yogurt should have a sour smell. If the yogurt smells different, particularly if the scent is yeasty, throw it away. A yeast smell is a sign of bacteria taking over the yogurt.

• 3

  Check the top of the yogurt for visible mold. Any irregularity or fuzziness indicates that the yogurt is probably spoiled. However, if the yogurt has a layer of liquid on top, that is fine. Yogurt naturally separates in the refrigerator and needs to have its watery top layer stirred back in before it's consumed.

• 4

  Take a very small taste of the yogurt. As long as it is a teaspoonful or less, this method of determining yogurt spoilage shouldn't hurt you. If the yogurt tastes yeasty or overly sour, throw it away.

• 5

  Look for textural inconsistencies by stirring the yogurt with a spoon. If the yogurt has solid lumps in it that can't be easily broken up by the stirring motion, it should be discarded.