Sugar, honey, or preserves can cause a sauce to burn on the meat's exterior before the meat is fully cooked. To avoid burning the meat, wait until the last 5 or 10 minutes of grilling to brush on sweet sauces. If you wish to serve a sauce at the table, divide it before you brush part of it onto raw meat. Or, if you've brushed on a sauce, boil the remainder in a pan before passing.