Does natural {peanut, cashew, almond} butter require refrigeration? I have purchased a few different types of natural peanut butter and all have stated that refrigeration is required after opening. However, I recently purchased Archer's Farms Almond, Peanut &amp; Cashew Butter from Target which doesn't say anything about refrigeration after opening. From what I've read on other sites (anecdotal) and some .edu sites, raw/natural nut butters can grow mold and do require refrigeration. Any ideas on why Archer's Farms butter doesn't say anything about refrigeration?



Peanut butter
unopened           6-9 months    Refrigeration not needed. Keeps
opened             2-3 months    longer if refrigerated. Natural
                                   peanut butter must be
                                   refrigerated after opening.



http://www.ag.ndsu.edu/pubs/yf/foods/fn579-2.htm
I don't think I've ever seen peanut butter grow mold, natural or commercial, refrigerated or not. What will happen with natural peanut butter is that the fat (of which there's plenty) will go rancid over time.

The oxidation process that leads to rancidity requires heat, light, and usually oxygen; keeping it in the refrigerator will therefore slow the process down significantly.

Manufacturers are probably not required to put the "keep refrigerated" warning on nut butters because eating rancid food technically won't kill you or make you seriously ill. When a product says to keep refrigerated, sometimes that's for safety, sometimes it's just for quality - in the case of peanut butter it's typically the latter.

Commercial peanut butter has a ton of sugar and other preservatives, which is why refrigeration is not necessary, even for quality purposes.