Examples of techniques for monitoring and controlling the pH of a drilling fluid are disclosed. In one example implementation, a method may include monitoring, by a first sensor, a first pH-value of the drilling fluid prior to the drilling fluid being heated. The method may further include monitoring, by a second sensor, a second pH-value of the drilling fluid subsequent to the drilling fluid being heated. The method may further include determining, by a processing system, an amount of additive being added to the drilling fluid to alter the pH of the drilling fluid.