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Why Does Pasteurized Milk Still Go Bad Over Time?

Learn why pasteurized milk eventually spoils despite bacterial reduction and how storage affects its shelf life.

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Video transcript

Milk eventually goes bad despite being pasteurized because pasteurization kills most, but not all, bacteria. Over time, the remaining bacteria can multiply, leading to spoilage. Additionally, once the milk is opened, it's exposed to new bacteria from the environment. Proper refrigeration can slow this process but won't stop it entirely.

Questions and answers

  1. What is pasteurization and how does it affect milk?

    Pasteurization is a heat treatment process that kills most harmful bacteria in milk, extending its shelf life but not completely sterilizing it.

  2. Why does milk spoil faster after opening?

    Once opened, milk is exposed to new bacteria from the environment, which can multiply and cause the milk to spoil more quickly.

  3. How can refrigeration slow down milk spoilage?

    Refrigeration slows bacterial growth by keeping milk at a lower temperature, thus extending its freshness, though it cannot prevent spoilage entirely.

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For more insights on dairy safety and preservation, explore our videos on milk storage tips, pasteurization processes, and how to extend the freshness of dairy products.