Why does milk, cream, yogurt, etc. become rancid if left unrefrigerated, but butter can just freeball in a butter dish for-seemingly-ever and still be safe and edible?

Question

I just don’t get it. I’m sure there’s a very sciency explanation, but it makes no sense to me. I love that it can sit out to be soft and spreadable, but you try that with cream and you’re on the way to a stinky cheese, milk or yogurt you’ve just got a curdled surprise.

So why can butter just sit out and not start to stink or become dangerous to eat?

In: 122

Answer 1

I feel there is a true ELIF missing.

Here’s my try. Food doesn’t go bad by itself. If you threw a hot dog into space it would be fine to eat for a very very long time. What happens is little creatures, like bacteria and fungi start eating some components of the food. Most of them need also water and oxygen to live, but some don’t. Also, some parts of the food can go bad from contact with oxygen (oxidation) sunlight (UV) or degrade with changes in temperature. Butter is made by removing most of the water, and the remainder is in very small separated droplets so microorganisms can’t damage it easily.

However oxygen and light do degrade the fats in the butter, creating a rancid flavor. So even if its safe to eat, the taste will grow worse after a few days without refrigeration.