I recently bought some natural peanut butter from our co-op. You even get to grind it up yourself! It's just unsalted organic peanuts, and nothing else is added to it. Do I need to keep it refrigerated? I googled but came up with mixed results. I don't want the peanut butter to go bad, but when I used it today for the first time (after being kept in the refrigerator) it was really hard and therefore difficult to spread. So, for those of you who buy similar peanut butter, do you keep yours in the fridge? Thanks a lot.