Why does milk develop chalky flavor in old plastic bottles?

Question

Noticed a chalky or plastic-like taste from milk stored in an old bottle? Learn how the container material can affect the flavor of your dairy.

Answer 1

Milk develops a chalky flavor in old plastic bottles due to the plastic absorbing flavors and odors over time, and potentially leaching chemicals into the milk. This is exacerbated by repeated use and washing.

Detailed Explanation:

Plastic, especially the types commonly used for milk bottles, is porous to some extent. This means it can absorb flavors and odors from its environment, including the milk itself and cleaning agents used to wash the bottle. Over time, these absorbed substances can impart an off-flavor to the milk, often described as chalky or plastic-like. Furthermore, some plastics can degrade slightly with repeated use and washing, potentially releasing small amounts of chemicals into the milk. While these chemicals are generally present in very low concentrations, they can still affect the taste and quality of the milk. The older the bottle and the more frequently it's used, the more pronounced this effect becomes. The type of plastic also plays a role; some plastics are more prone to absorbing odors and leaching chemicals than others.

Pro Tip:

To minimize chalky flavors, avoid reusing plastic milk bottles for extended periods. Consider using glass or stainless steel containers for storing milk, as these materials are less likely to absorb odors or leach chemicals.