I followed all of the tips. Prime sirloin, taken out an hour before cooking. Salted thoroughly 30 minutes prior. Patted dry with paper towels. Thrown on a high (650) degree grill for two minutes per side, finished on low for 3 minutes per side (internal temp was still about 400). Rested 10 minutes.
Results: Good sear, beautiful medium-rate insides. Plenty of juice. Enough salt.
Problem: the exterior was almost like bark. It wasn't scorched or burnt, but just really really dry.
What was the misstep?
Best Answer
It sounds like you may be searing the steak for too long. Indeed, you want to initially be cooking the steak at a higher-than-normal temperature in order to sear it, but I'd suggest a period of more like 30 seconds each side, followed by slightly longer at a reduce temperature. At 650 degrees, the steak does not need long to sear. The same principle has worked for me when pan-frying steak, though obviously at much lower temperatures.
I'm not sure how large a role the salting is playing, but I would only salt the steak minimally before cooking. It's often just as well done towards the end of cooking, and is less likely to dry out the steak.
In addition, a common mistake is to pat down the steaks too much while (or after) cooking them. This may speed up the process slightly, but it certainly dries out the meat (the outside in particular). This is probably not the main problem, but is worth noting anyway.
Hope that helps.