Why is there a layer of oil on top of my peanut butter?

As we do not use any emulsifiers in our nut butters, there can be a natural separation of the oil.
If the nut butter jar is stored in a cooler environment, the level of separation can be more prominent. In this case we would usually recommend that you place the jar in a warm water bath for about 5 minutes to loosen the nut solids to make it easier to recombine the product.