Hi, just joined and don't make a lot of brisket as don't often have that many people by. My results have mostly been underwhelming - flat top dry and point too fatty. But the last two worked out really well. So much so that our neighbors's mum, visiting from St Louis and a big fan of Joe's brisket, said mine was not quite there but close.
This is what worked for me. One big change from previous briskets is using an indirect heat gravity charcoal grill, loaded with a mixture of charcoal and wood chunks. Previously had used cheap offset smoker (could never make it work very well) and a kettle grill with a Slow N Sear (worked much better than cheap offset but wanted fully automated temperature control).
I start with USDA prime full brisket trimmed to about 1/4" fat with salt and pepper rub 24 hours before. A fillet knife is useful for trimming. I also inject with beef bone stock but am not sure it's necessary. I have a
Char-Griller 980 - which has its own annoyances - but it is indirect heat. Pellet grills are direct heat so you may want to use a pan full of water or sand under the brisket to deflect the heat (or under any other thing that is cooked at low temperature for a long time).
Render the trimmed fat by covering in water in a sauce pan and cooking at very low simmer until there are a few crispy bits, then strain into a jar and refrigerate.
I use a leave in Bluetooth thermometer. If you haven't bought a remote thermometer yet, consider a WiFi one. It costs more but will work anywhere and the maker can push firmware updates. Bluetooth was always meant for a short range and as it's not connected to internet no firmware updates. My Bluetooth thermometer drops if I go inside, which is not ideal when cooking outdoors during an upstate New York winter.
But to think of it, not sure what firmware updates a thermometer might need.
It smokes at 225F for maybe 6 to 8 hours until internal temperature reaches 150 to 160F. At about 140F start checking with a digital instant read thermometer. The leave-in thermometer may not reflect true temperature as the probe is inside cook chamber.
Melt the beef fat you rendered, baste the brisket with the fat, then wrap in butcher paper at 150 to 160F. I have been wrapping in tin foil and sometimes the brisket comes out tasting a bit like pot roast. A bit of research suggests that one cause of that may be that the brisket more or less braises in the sealed tin foil as opposed to having some airflow using the butcher paper. Butcher paper is also better at preserving the bark.
Am also not sure basting with beef fat is necessary, but it is a part of my current process and if something works I am reluctant to experiment.
Cook to 190 to 200F. I like the point and flat sliced, so don't want to cook the point until it's at a pulled pork consistentcy. I have only used prime so don't have experience with choice, but research suggests prime can come off the smoker at a bit lower temperature than choice.
People that make a lot of brisket will say they can tell it's done by poking or prodding it. I don't make enough brisket to be able to tell that way.
Then put it in a warmed cooler for an hour or four. First, people seem to agree it needs to rest for a good final result. Second, the brisket can then be served whenever people show up and are already eat. As BBQ is done when it's done and a brisket smoked at 225F may take 7 or 8 hours or it may take 12 or 14 hours. On more than one occasion I have had people drop by for slow cooked BBQ, hang out with drinks and appetizers until long after I said dinner would be done, and then finally leave without eating as dinner still wasn't done.
People who have been drinking for a few hours without eating tend to get cranky and a bit mean, and unsympathetic to statements like "BBQ is done when it's done! Have some more Cheetos..."
Finally unwrap. I put mine on a gas grill preheated to super high for a few minutes a side to crisp the bark, but I don't think it's necessary.
How it is sliced is important. I am not skilled enough to find and sperate flat and point. So I start with point - easy to identify - slicing thinly at right angles (could also say "orthogonal to" as I about never get a chance to use that word) to the brisket's long side centerline. At some point (pun intended...) you will notice the texture and directiction for the brisket's grain change. You have found the flat. Change slicing angle so you continue to slice across the grain.
For same slicing reason, turkey or chicken breasts are much better when removed from carcass and sliced against grain, as opposed to carving with the grain on the carcass.
Finally, note a lot of people like to smoke point and flat separately. If you are like me and have no butcher skills, just go to a real butcher shop to buy the brisket and ask the butcher to separate -grocery store butchers generally won't do that. I have not smoked them separately, but it is probably easier to get a reproducibly good result that way.
I hope this was helpful.