So how do you Season a Cast-Iron Grate?

Start with a screaming hot grill grate. Brush it with a stiff wire brush. And oil it generously with a tightly folded paper towel dipped in vegetable oil (preferably grape-seed, safflower, or peanut oil, not corn oil). Hold the paper towel with tongs and draw it across the bars of the grate. (You can also oil a grill grate with a chunk of beef or pork fat.) Repeat this process before you start grilling and as soon as you’re finished—the practice should become second nature. The more often you do this, the better seasoned your grill will be.