Let the charcoal or briquettes burn until they’re covered with white-gray ash (it takes about 5-10 minutes for the coals to get to high heat and 25-30 minutes to get to medium heat).
You can gauge how hot your coals are by placing your hand at about the level of the grill or approximately five to seven inches above the coals (use your head here, no suing for burned hands). If you can do the backstroke in them, that means you forgot to light them.
Lump charcoal is very sensitive to airflow and venting. Typically it is ready to be cooked over within 15 minutes and will stay hot up to an hour. Since it burns more quickly than briquets, additional charcoal can be added to the fire at any stage to prolong the fire.
A properly built fire should stay hot enough to cook for 30-40 minutes.
The lid should be open while you arrange and light your charcoal. Once the coals are well-lit, close the lid. Most charcoal grills are hotter right after lighting. The heat then tapers off.
If your grill is full of ashes from the last time you grilled it can impede the proper flow of air inside of the kettle, which makes the coals burn cooler. Fire needs oxygen, and if enough ash builds up inside of the grill it can make it next to impossible to get the coals burning well, or to keep them lit.
Wait until your charcoal has burned to an even temperature before placing any meat on the grill grates. When the charcoal firsts turns white, it is hot on the outside, but still cool on the inside. You want to wait until at least 2/3rds of the charcoal have turned white and the charcoal has stopped smoking.
Grills usually have a fixed distance at 5” between the grill and the top of the charcoal. At a distance of 5″, the temperature of a “normal” charcoal fire will be between about 370°.
You can. If you add them directly over the burning coals it might lower your temp.
No problem using lump in a Weber kettle. I even used to use lump when I had a little Smokey Joe. It got super hot a few times. No ill effects.
If you want to step up a level, you can use lump charcoal. Lump charcoal typically burns cleaner than briquettes and produces much less ash. It also burns hotter, but you can control the temperature by using the adjustable air vents of your smoker.
So lump charcoal should burn for 4-6 hours versus your briquettes giving you a good 8-10 hours. Of course, every BBQ is different and these burn times are dependent on your fire management and ultimately how well you can control the airflow.
Regardless of which vent you’re messing with, remember that open vents mean hotter and faster-burning charcoal. Closed vents mean less oxygen, which in turn means less heat and slower-burning charcoal. Now that you know about vents, the world—or at least your grill and the small area surrounding it—is yours.
Coals can always take a very long time to cool down, and it’s also not always clear if they’re still burning or not, I recommend leaving the grill for up to 48 hours, with all vents closed. While it might not take this long to extinguish, it’s important to be absolutely certain.