Refrigerating peanut butter after opening it is not necessary, but it can affect the texture and consistency of the peanut butter. Whether you choose to refrigerate it or not depends on your personal preference and how you like your peanut butter.
Refrigeration can cause the peanut butter to thicken and become harder, making it less spreadable. This is because the cold temperatures cause the natural oils in the peanut butter to solidify. If you prefer a smoother and softer texture, you may want to keep the peanut butter at room temperature.
On the other hand, refrigeration can help extend the shelf life of peanut butter, especially if it contains added oils or is a natural variety without preservatives. The cooler temperatures in the refrigerator slow down the oxidation process and help prevent the oils from going rancid.
If you decide to refrigerate your peanut butter, it's essential to keep it in an airtight container to prevent it from absorbing any unwanted odors from other foods in the fridge.
Ultimately, whether to refrigerate peanut butter or not is a matter of personal preference. If you enjoy the convenience of a soft and spreadable peanut butter, storing it at room temperature is fine. But if you want to prolong its shelf life and don't mind a thicker texture, refrigeration can be a good option.