Well well. Upon examining the label more closely, I note that mine doesn’t even mention that it should be refrigerated. I always do anyway.
I find that it spreads easily enough when cold, provided that I have really stirred it well at first. As I noted, when I get to the lower half of the jar, it can be quite stiff if I didn’t stir it well enough.
I prefer Simply Jif or Jif Natural. Years ago, at a big flea market there was a man roasting peanuts. I bought some. They were delicious and when you cracked the shells, steam came out. IMO Jif tastes the most like fresh roasted peanuts.
I go through about a jar a week. I never refrigerate. The Cape May Peanut Butter Co makes fantastic products. I thought chocolate or butterscotch pb would be my favorite. It turned out to be cappucina pb.
There’s a difference between “hydrogenated” and “partially hydrogenated”. Hydrogenated oil is saturated fat, which probably isn’t all that great for you, but it’s not all that terrible, either. Most natural fats that are solid, or close to it, at room temperature are saturated, and hydrogenating other fats produces similar effects.
Partially-hydrogenated fats mean that you get a mixture of saturated, unsaturated, and trans fats. Trans fats were originally developed because they’re unsaturated, but have similar bulk properties as saturated fats, and it was thought that they’d be a healthier replacement for saturated fats.
Turns out that’s wrong: Trans fats are now pretty clearly known to be definitely worse than saturated fats. So the solution is simple: Nobody uses them any more for anything. If they hydrogenate some other fat, they do so completely. If they want a fat in a texture somewhere in between the original liquid state and the solid fully-saturated state, they fully-saturate some, and mix it with the appropriate amount of unsaturated.
And as an added bonus, now they get to put big labels on the front saying “No Trans Fats”, so everyone knows they’re healthy.
Huh. I just checked my jar of Smucker’s Natural and sure enough, no mention of refrigeration. I would swear that it used to say that it had to be refrigerated, though.
I suspect that if I didn’t refrigerate, the oil would separate again. I don’t want to deep stir this more than once, so I’ll continue storing it in the fridge.
I just checked in our pantry to see if our supermarket peanut butter had any labeling instructions, but we currently only have the fresh made honey nut.
The Jif/whatever was what I used to bait mousetraps. It had a Sharpie drawn skull and crossbones on it. I must have thrown it out after noticing our “good” peanut butter was preferred by mice.
I have never refrigerated peanut butter. Did not know that was a thing for the first decade or so of my life.
Here is what I think I know about this: (My cite: A friend from years ago who had a PhD in biochemistry and did some research in the field, I think, who explained this to me.)
When an unsaturated fat molecule gains two extra hydrogens to become a saturated fat, it can do so in a cis or a trans configuration. When this is done naturally, it is done by enzymes that are very specific in their workings, always producing cis fats.
But when fats are saturated artificially, in the process invented by Crisco in the late 19th century, they put corn oil into an industrial-size pressure cooker with hydrogen gas and pressurized it until the H saturated the fats. This was where the molecules would randomly become cis saturated fats or trans saturated fats.
And after that was when people started dying of clogged arteries. An entire several generations of people, in America in particular, were poisoned by Crisco and all the copycat products. Eventually, it was understood that hydrogenated fats were killing people, and we were all taught to avoid the same.
It was only later (relatively recently, sort-of) that we all learned that it was trans fat specifically that clog your arteries. And we learned that “partially saturated” fats were just about as bad.
Thus, for example, a certain other friend told me that he went back to using butter instead of margarine, as it was really the partially hydrogenated oil in margarine, not the saturated fat in butter, that was killing people.
I decided to believe that, and now I too use butter instead of margarine. I now believe that it is not, and never was, saturated fat, per se, that is bad for you. Just the trans fat fraction thereof.
I believe now that products like Crisco are now made in a way that either prevents trans fats, or they are somehow filtered out at some point in the process, so these kinds of products no longer contain (much) trans fat.
The problem with trans fat is, first, it is solid-ish at room temperature, and sticky, so it clogs arteries. Worse, because it does not naturally occur (much), and because our bodies use very specific enzymes to metabolize such stuff, we have no enzymes for metabolizing (“burning off”) trans fat. We have no mechanism for getting rid of the stuff. So it just keeps accumulating in our bodies until it kills us.
This is my solution. I use Adams crunchy style and don’t eat enough PB on the regular to keep it from getting rancid if unrefrigerated, but a minute in the microwave and it’s the perfect consistency and temperature for whatever you need it for.
Not quite. A completely saturated fatty acid will be completely straight. Any place where it’s unsaturated, there’s a bend in the long molecule. If it has two spots where it’s unsaturated, then you get two bends, and those can be in a cis (both bending the same way) or trans (bending one way and then bending back the other) arrangement. The trans fats, that bend back, are therefore close to straight, which is why they have similar properties to the completely-straight, completely-saturated fats.
I did a test for myself a couple years ago, and posted the results on the Dope, and of Jif, Skippy, and Peter Pan, it was Jif>Skippy>Peter Pan, for my tastes, with Jif having more of a “roasted” flavor than the other two. Creamy was the type selected for the taste test. Skippy had been, up until that point, my usual peanut butter of choice, but since then it’s been Jif and Smucker’s Natural.
And I just leave them room temperature in the cupboard.
Jif Creamy for me, at room temperature. I keep the jar on top of the fridge.
And no jelly. Just peanut butter on bread.
Repeat this comparing results in baiting mouse traps, then we’ll talk. 
A few years ago, I bought some organic/natural peanut butter for a while; I recall that that package did advise refrigerating.
I’ve eaten Skippy (Superchunk variety) since I was a kid, and it’s never been stored in the fridge. If a jar has been open for more than a couple of months, it can get a bit rancid, but the secret then becomes “eat it more often.”
Reading this thread makes me think that I eat an unusually large amount of peanut butter.
@Thudlow_Boink In hindsight, this is all I could find. 
I buy the largest jar of whatever is on sale. Chunky variety. No refrigeration necessary. Doesn’t last long enough to go bad anyway.
I haven’t bought peanut butter in many years but my family always kept it refrigerated and it was never “rock hard” or difficult to spread on bread. 
The only time ive seen refrigerated peanut butter is when grandma mixed honey with hers
I’m in the UK, eat peanut butter regularly and have never refrigerated it. 
The ingredients for my supermarket peanut butter are:
The label says ‘store in a cool dry place’.and that it is ‘best before’ 12 months ahead.
(It’s suitable for vegans too.)
I’ve always kept peanut butter on a kitchen shelf or in the pantry, thus at room temp, never in the fridge. So has most everyone I know who uses PB. Do people really refrigerate it?
ETA: Laura Scudder’s Creamy (just peanuts and salt, needs to be stirred) is our preferred brand but we keep a jar of the processed kiddie stuff around for when instant gratification is needed.