[leephillips]

People living in industrialized societies, especially the US, are accustomed to the taste of old food, and fresh food tastes wrong to them. Testing packaging that reduces the rate of oxidation exposed this taste preference: in tests many US people preferred slightly oxidized milk, etc., although objectively this is a form of spoilage. Similarly, some people prefer the distorted sound of LPs to accurately reproduced music. People prefer what they’re used to.

[technothrasher]

I can't stand even slightly rancid oils, and I've found that most people don't notice it at all until you point it out to them. Rancid vs fresh peanut butter is the most noticeable one to let people taste test next to each other. Once they identify the rancid smell and flavor they all agree the fresh is better. Though a couple of times I've hit people who just cannot tell the difference. I envy them.