If you keep your natural peanut butter in the refrigerator (which you should do since germs can grow in it if it stored in the cupboard), once you get near the bottom of the jar, the peanut butter will get very hard and be hard to spread without tearing your bread. If this happens to you, stick you jar of peanut butter (without the metal cap) in the microwave oven for 15 - 30 seconds. This will warm up the peanut butter and allow the oil to flow so that your peanut butter is then nice and easy to spread.