Which milk quality defect is most commonly associated with high bacterial counts?

The connection between high bacterial counts and off-flavors in milk is well-established. When bacterial levels are elevated, especially in raw or improperly handled milk, the bacteria can produce metabolic byproducts that alter the flavor profile of the milk. These alterations can manifest as sour, rancid, or stale flavors, which are not desirable in milk quality.

Bacteria, particularly those from the coliform group and certain spoilage organisms, contribute to these off-flavors by breaking down milk proteins and fats, leading to the development of undesirable compounds. As a result, maintaining low bacterial counts is crucial for preserving the fresh taste and overall quality of milk.

In contrast, while high acidity can be related to bacterial activity, it is more of a secondary effect rather than a primary quality defect identified in association with high bacterial counts. Low viscosity and excess water are less directly related to bacterial counts and are more associated with other factors affecting the milk’s physical properties. Thus, off-flavors are the most commonly recognized defect arising from high bacterial counts in milk.