lots of US peanut butters are “no-stir” by substituting some of the oil with basically a margarine-like fat (solid, hydrogenated oils replace some of the peanut oil so that the oil never separates and needs to be stirred in again)
If you use normal peanut butter, here are some tips I’ve found:
- turn the peanut butter jar upside down so the lid is at the bottom where the solid peanut butter collects, and the oil collects at the “top” (which is now the bottom of the jar). This means when you open the jar and stir it, the oil is already at the bottom and you don’t have hard peanut butter stuck at the bottom that you can’t ever get incorporated
- once you have opened a new jar and stirred it thoroughly, store the peanut butter in the fridge to make the peanut oil become more solid and doesn’t separate as quickly, and in my experience this prevents having to stir it again for the rest of the life of the jar
But I also just eat the no-stir hydrogenated peanut butter now because it’s extremely cheap and I’m unemployed.