To dry peppers without molding, ensure they are fully ripe and free from any signs of damage or moisture. Cut them into thin slices or halves, and either sun-dry them in a dry, warm, and well-ventilated area, or use a dehydrator set at a low temperature to remove all moisture from the peppers. Properly dried peppers should be stored in an airtight container away from direct light and moisture to prevent molding.