Eli5: why does “good” peanut butter need to be refrigerated?

Question

The only ingredients on the label are “peanuts, salt.”

We keep peanuts unrefrigerated in the pantry… we keep salt unrefrigerated in the pantry… so how come when you mash them together it makes something that (according to the jar) must be refrigerated after opening?

P.S. I put “good” in quotes because all peanut butter is good. What I mean by “good” peanut butter is the healthier stuff that you have to mix the oil back into and there are only the above mentioned ingredients.

In: 2133

Answer 1

I think it’s to prevent the oil from separating out. Keeping it refrigerated makes everything more viscous and prevents separation. I don’t know if this means it’s good or not, but generally this is the case for products that doesn’t have any emulsifiers added. If your peanut butter has emulsifiers then the oil won’t separate out.