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

Butter is about 80% fat, a few % milk solids, and the rest is water. Fat/Oil is not an ideal growth medium for bacteria. All the other things you listed have much more water and sugars(lactose). That is Great medium for bacteria growth.