You can store leftover Korean fried chicken wings in an airtight container in the refrigerator for up to 3 days. Keep in mind if the chicken is already covered in sauce, it would be as crispy once you warm it up. It is best to store the leftover chicken and wing sauce separately. Then, you can reheat the chicken in the oven, toaster oven, or air-fryer to get them nice and crispy. And dunk the chicken in warm sauce before serving!