Why is relying solely on sour odor insufficient for determining food safety?

Dangerous pathogens that cause foodborne illness might not produce any smell at all.

While smell is often the initial warning sign, relying exclusively on it for determining food safety is dangerous because spoilage organisms, which produce noticeable sour or off-odors from bacterial, yeast, or mold activity, are distinct from pathogenic organisms. Specifically, hazardous foodborne pathogens, such as those leading to severe illness, frequently do not generate any perceptible odor or visual change in the food product, even when the food is unsafe for consumption. Therefore, food can smell perfectly fine while still harboring dangerous levels of contaminants. This highlights the necessity of employing multiple assessment layers, such as visual inspection and texture checks, instead of depending on the presence or absence of an odor as the sole determinant of safety.