Cover the chicken and let marinate in the refrigerator for at least 2 hours and up to 8. (What will happen if you marinate it longer? Well, it won't be terrible, but the longer proteins sit in a salty mixture, the more cured a texture they begin to take on. You can actually let this marinade go for 2 or 3 days before you cook the chicken, but I think up to 8 hours for chicken breast keeps optimal texture. Up to overnight for dark meat.)