The intensity of a grill's heat and the simple change of scene from kitchen to backyard can sometimes cause uncertainty over how long foods need to cook to the desired degree of doneness. The information below provides some general guidelines for direct-heat grilling. For indirect-heat grilling, which takes longer, refer to instructions in specific recipes.
Remember that some simple tools and common sense can also help. For meats and poultry, use an instant-read thermometer that will quickly gauge the internal temperature of a piece of food. And nothing beats the information you gain by cutting into a steak, chop, burger or fish fillet with a sharp knife or the edge of a spatula to see if it is cooked through to your liking.
Keep in mind that times will vary with the particular type of grill and fuel you are using and the specific ingredients you have chosen. It's not a substitute for what your own senses and judgment tell you.
Fish should be cooked until it flakes when a knife is inserted into the flesh. Figure on an average of 8 to 10 minutes per inch of thickness. Shrimp should be cooked until uniformly opaque throughout. Clams, mussels and oysters should be well scrubbed before cooking. Discard any that are not tightly closed. Cook them just until their shells open, and discard any that do not open.
Chicken and turkey are done when they are cooked through completely, with no trace of pink remaining at the bone or at the center of boneless pieces. When pieces are pierced with a long-handled fork, the juices should run clear. The doneness of larger poultry pieces may also be checked with an instant-read thermometer inserted into the center of the meat, away from the bone; it should register 165°F for white meat, 170°F for dark meat for chicken (175°F for turkey).
To visually assess the doneness of meat on a grill, cut into the thickest part of one serving. Rare meat will look rosy pink in the center, medium-rare will be light pink in the center, and medium will have just a trace of pink. Cooking meat beyond medium runs the risk of it drying out and turning tough. (Burgers are an exception; for safety's sake, they should be cooked no less than medium, and many health experts say it is wiser to cook them at least medium-well.) If using an instant-read thermometer, insert it into the thickest part of a piece of meat, away from the bone. It should register 125°F for very rare to rare beef or lamb, 130°F for medium-rare and 135°F for medium. Pork should be cooked to 140°F for medium, 150°F for medium-well.
Adapted from Williams-Sonoma Complete Grilling Cookbook, Edited by Chuck Williams (Time-Life Books, 2001).