Season chicken with salt and pepper. Place 1 chicken breast in each bag. Seal each bag with vacuum sealer according to manufacturer’s instructions. Refrigerate chicken until ready to use. Once water reaches sous vide machine’s set temperature (165°F), lower prepared bags into water bath, and continue to cook at least 1 1/2 hours and up to 2 1/2 hours or until chicken breasts reach 165°F. Carefully remove bags from water bath. Cut open bags, and transfer chicken breasts to plate; discard remaining liquid in bags, and pat chicken breasts dry.