How to make the camera rotate up to act as recoil?

I am trying to make my first game in unity, being a FPS. I have all of the controls and am working on animations, but I cannot get recoil working. I am currently running the following script if the player is holding left mouse button down: Camera.main.transform.Rotate( recoil * Time.deltaTime, 0, 0 ) ; recoil is currently set using float recoil = 10.0f;. But all this code is doing is jolting the screen slightly, not making the camera slowly travel up. I gave up building this FPS for some time, but after coming back to try and do more work I still cannot get this recoil working. Any help would be greatly appreciated.