No matter what kind of grill you have, you’ll need two heat zones to cook a steak. A high heat area for searing and a medium heat area to finish it to the desired level. Here’s how to set it up.
Searing is a technique where food is cooked at a high temperature until a browned crust forms due to the Maillard reaction. This high heat causes the molecules to rearrange themselves and set off multiple reactions that brown the steak and unlock the flavor and aroma. It’s about 500 degrees F for perfect seared steak. If the steak is left on this heat for too long the crust will burn and produce a bitter taste. Moving the steak to a medium side of the grill will maintain flavor and allow the steak to cook to the preferred doneness.
When setting up your cooking zones on a charcoal grill, bank most of the hot coals to one side of the grill. This will serve as the high heat zone while the other side will be the medium heat zone. Open your vents wider to heat up the grill and close them to cool the grill down. If you have a gas grill, turn two knobs to high and let the grill heat for about 10 minutes. Once it reaches temperature, turn one knob down to medium to create the medium heat zone.
You can test the cooking zones by holding your hand three inches about the hot zone. If you can hold your hand for two seconds, the grill is ready for searing. The medium zone is ready if you can hold your hand there for 5 to 7 seconds. Don’t forget that charcoal is the hottest 5 to 10 minutes after lighting. You may be tempted to sear right away but it could take about 25 minutes for the medium zone to reach temperature. Wait until almost all the charcoal is white and has stopped smoking.
Source: Simply Recipes