If you are slow cooking your brisket on the Kong kamado charcoal grill, start your fire about an hour before you are ready put your brisket on. You want to have your grill temperature up to at least 250 degrees and steady light blue smoke coming from the top vent.If you are cooking your brisket on the Grilla or Silverbac pellet grill, start your pit about 20 minutes prior to putting your brisket on. You want to achieve a grill temperature of 275 degrees. Once you place your meat on the pit, feel free to top off with any rub and seasonings of your choice. Check the brisket every hour for the first 2 hours, then every 30 to 45 minutes thereafter. What you are looking for is the color you want, as well as puddling juices on the surface of the meat. This will happen at an internal temp of about 150 to 165 degrees. Wrap the brisket with foil once the brisket reaches this phase.
When foil-wrapping your brisket, use two layers of foil to guard against accidental holes in the bottom layer and seal tightly. You want to preserve as much moisture and juice as possible (this will prove valuable later).
Once the brisket is wrapped, it will not take long for it to hit the target internal temperature—between 195 and 205 degrees across the whole brisket (most importantly in the flat). When measuring the temp with your Thermapen, take the time to feel the resistance of the meat. The point will be more forgiving since it has considerably more fat. If the meat feels super stiff yet, it may require a few more degrees of cooking time. The brisket will relax as it rests, so don’t worry if the brisket is not super tender at this point.
As soon as you have verified the temperature of the brisket, you will need to vent the foil to let steam out and stop the cooking process, while still on the grill. Leave the foil open for a minute or two, just long enough to vent all the built-up steam.
Once the brisket is vented, remove the brisket from the grill, wrap it back up in the foil, cover with a towel and let rest in a cooler or warming box, keeping it warm for at least 2 hours (4 hours preferable).
After letting the brisket rest you can separate the point from the flat, sliding a knife between the two pieces. Use caution, as the brisket will still be very hot.
A quick reminder on slicing: you can ruin a brisket at the very end by slicing it wrong. You have to find the grain of the brisket (refer back to the trimming section) and cut 90 degrees across that grain. Only by doing that, will you achieve perfectly tender results. Once sliced, place those slices back in all that juice—the freshly cut brisket will soak up a bit of the juice like a sponge.
Take the remaining au jus and use for gravy, pan sauce, dipping sauce for a brisket French dip sandwich, or just bag it, freeze it and then add it to pot roasts that you cook in the crock pot.