Well, I am happy to report that storing it in the fridge upside down has caused the PB oil to rise to the top (which is the bottom of the jar) and this produces a slightly lower fat product. When I get to the oily part on the bottom of the near empty jar, I remove it and use the jar to the end.
I would suggest that you check the consistency of the PB at the very bottom of the jar, as it sometimes needs a smidge of the oil mixed back in to become pliable. To date, none of the PB upside down jars have leaked. However, if you share the PB with other family members, they may not be as cautious as you by tightening the lid.
By Holly from Richardson, TX