Boiled peanuts are made by, well, boiling raw peanuts in water, usually with some added salt and spices. This process makes them super tender and full of flavor. But, it also makes them more prone to spoilage, kind of like how a freshly baked cookie is more likely to get stale faster than a stored cookie.
When boiled peanuts are exposed to heat, moisture, or air, they can start to break down and become a breeding ground for bacteria. It's like when you leave a slice of bread out too long and it starts to get all moldy. Not exactly what you want to happen to your tasty boiled peanuts.
