Never make burgers with anything less than 20% fat. If you have a good relationship with your butcher see if he can grind in a few slices of bacon to bump up the fat content as well as flavor.
I find this recipe to work really well and despite their warning i never cook past medium and they taste wonderful and i feel no ill effects.
FOOLPROOF BACKYARD BURGERS
Adding bread and milk to the beef creates burgers that are juicy and tender even when well-done. (In fact, we recommend this method only for burgers that will be cooked to medium-well or well-done.) For cheeseburgers, follow the optional instructions below.
1 large slice good-quality white sandwich bread, crust removed and discarded; chop bread into 1?4-inch pieces (about 1?2 cup)
2 tablespoons whole milk
3?4 teaspoon table salt
3?4 teaspoon ground black pepper
1 medium garlic clove, minced or pressed through garlic press (about 1 teaspoon)
2 teaspoons steak sauce
1 1?2 pounds 80 percent lean ground chuck
Vegetable oil for cooking grate
6 ounces sliced cheese, optional (see note above)
4 rolls or buns
1. Using a large chimney starter, ignite 6 quarts charcoal (about 100 briquettes) and burn until covered with thin coating of light gray ash, about 20 minutes. Empty coals into grill; build modified two-level fire by arranging coals to cover half of grill. Position cooking grate over coals, cover grill, and heat grate for 5 minutes; scrape grate clean with grill brush. Grill is ready when coals are medium-hot (you can hold your hand 2 inches above grate for 3 to 4 seconds).
2. Meanwhile, mash bread and milk in large bowl with fork until homogeneous (you should have about 1?4 cup). Stir in salt, pepper, garlic, and steak sauce.
3. Break up beef into small pieces over bread mixture. Using fork or hands, lightly mix together until mixture forms cohesive mass. Divide meat into four equal portions. Gently toss one portion of meat back and forth between hands to form loose ball. Gently flatten into 3?4-inch-thick patty that measures about 4 1?2 inches in diameter. Press center of patty down with fingertips until it is about 1?2 inch thick, creating slight depression in each patty. Repeat with remaining portions of meat.
4. Lightly dip wad of paper towels in oil; holding wad with tongs, wipe cooking grate. Grill burgers on hot side of grill, uncovered, until well seared on first side, 2 to 4 minutes. Using wide metal spatula, flip burgers and continue grilling, about 3 minutes for medium-well or 4 minutes for well-done. (Add cheese, if using, about 2 minutes before reaching desired doneness, covering burgers with disposable aluminum pan to melt cheese.)