Close the lid and turn all burners to the highest heat setting for about 10–15 minutes. When smoke stops flowing from the back of the grill, you’ll know the burn-off process is complete. Turn the burners off, disconnect the gas if necessary, and let the grill cool off to a moderate temperature of about 250-300 degrees Fahrenheit before scraping the residue.
Grill brushes are the most common tool used for the job, but you can also loosely pack a few feet of foil into a ball and pair that with tongs to create a makeshift scrubber. No matter which method you choose, brush back to front once on every grate before checking to see if there are any spots that need more work. This should be fairly easy if you allowed enough time for burn-off.
Once the grates are clean, season them with a thin coat of high-smoke point oil (we prefer palm or grapeseed) to prevent food from sticking the next time you fire up the grill. It’s important to clean your grates after each cook to prevent caramelized buildup from wearing them down or causing food to stick to the cooking surface during your next cookout.