When using a charcoal grill, it's important to allow enough time for the coals to fully ignite and heat up before cooking. Most charcoal briquettes require 20-30 minutes to reach optimal preheating temperature. Lump charcoal may only need 15-20 minutes due to its irregular shape and composition. For best results, resist the urge to start grilling too soon after lighting coals. Give them at least 20 minutes of preheating time for fiery Heat and flavor.