Oops! #1: You don't preheat the grill. The result: You incinerate the food. The Fix: Whether you're grilling with gas or charcoal, a steady, hot fire is crucial. Once the grill is turned on (or the coals are dumped beneath the grate), always close the lid and allow the grill to get hot. An eager griller may be tempted to skip this step, but if the heat doesn't have time to stabilize at the correct temperature, food will burn before it cooks through. As a general rule, allow about 10 minutes for a gas grill to heat up and about 30 to 40 minutes for charcoal.
Oops! #2: You grill over flames. The result: Meat that's both charred and undercooked, with a sooty residue to boot The Fix: Maintaining an even, powerful heat is important for great grilling, and cooking over embers is the key to an event heat. As a rule, charcoal and wood fires should be burned down to glowing embers before food ever touches the grate. Allow about 30 minutes from the time you light the fire, and wait until the coals have a bright-red glow with a gray, ashy look. It may take some time, but don't rush: Cooking over flames will scorch food quickly and unevenly, leaving you with charred and inedible results.
Oops! #3: You don't clean the grate every time. The result: The food sticks. The Fix: Before and after each grill session, clean the grates thoroughly with a wire brush. (A brass-bristle brush is best, since steel bristles can damage the enamel finish of some grates. Make sure the bristles are in good repair -- you don't want wayward bristles making their way into the food.) Each time you grill, preheat the rack with all burners on high for 10 to 15 minutes to incinerate any remaining residue from the last cookout, making it easy to clean off. Then, brush the grate vigorously with a grill brush so they're smooth and free from any stuck-on food. Finally, make sure to oil both the grates and the food. Cleaning the grill isn't just to prevent sticking. You'll also get the best flavors when you're not incorporating leftover bits from previous cookouts. See other essential grilling tools.
Oops! #4: You thoroughly mix burger patties. The result: Tough, dense burgers The Fix: Your own two hands are the ideal tools for shaping burgers, but too much manhandling will leave you with a finished product that's tough, not tender. For perfect patties, use a light touch and be careful not to compact the meat as you shape the patties. Work the ingredients evenly and lightly, enough to form a sturdy patty but no longer than necessary.
Oops! #5: You shape flat patties. The result: Your burgers has a bulge. The Fix: Use your thumb to make a small indentation in the center of each patty before tossing it on the grill. Burgers swell in the middle as they heat up, so this trick will help them hold their shape and cook evenly.
Oops! #6: You start basting with barbecue sauce immediately. The result: Sugary sauces scorch. The Fix: Sugar burns very quickly over high heat. When grilling with sweet, sugar-based sauces (several kinds of barbecue sauces fall into this category), always add them at the end of the cooking time (within the last 15 to 20 minutes), or use them when cooking over indirect heat. When using leftover marinade, don't baste burning the last 5 minutes of grill time, or you might not allow enough time for the heat to kill any bacteria that may be present.
Oops! #7: You check the doneness of meats by cutting into them. The result: Unattractive presentation and dry meat The Fix: Put down that knife! Juices settle in the center of a piece of meat as it cooks, and they need time to redistribute after coming off the grill. When you slice into meat to check doneness, all those yummy juices seep right out. Allow at least 5 to 10 minutes for meat to rest before cutting into it, and test for doneness with a meat thermometer instead of a knife. Place the thermometer in the thickest part of the meat, and for an accurate reading, make sure you're not touching bone, fat, gristle, or the filling in stuffed meat. Always err on the side of undercooking. You can easily throw it back on the grill for a few minutes, but once it's overcooked, there's no going back.