Rancid doesn't mean "completely rotten" even though some people use the term to only mean that. From wikipedia: > Rancidification is the process of complete or

Rancid doesn't mean "completely rotten" even though some people use the term to only mean that. From wikipedia: > Rancidification is the process of complete or incomplete autoxidation or hydrolysis of fats and oils when exposed to air, light, moisture, or bacterial action, producing short-chain aldehydes, ketones and free fatty acids.[1] > When these processes occur in food, undesirable odors and flavors can result. The end stage you describe is accurate, but since it's a process, people will call it rancid before the end stage. Further, since there is a large subjective factor in whether a flavor is undesirable, there are folks who will be more or less tolerant of those flavors - some folks will think the oil is fine or maybe a little stale, while others will be extremely sensitive gag at the same oil. Compare meat: there are people who think aged beef tastes rotten while others consider it a delicacy.