I just did my first brisket a few days back, and with all the great info I've learned from this forum, I thought I'd post up a few notes - might be helpful to someone. (Sorry if this should go somewhere else, I thought this would be a good place). Here are the specifics:
Brisket was 12# from Costco, a "full" cut, graded Choice.
About 6 hours before smoking, I trimmed most of the fat layer off (leaving 1/4 inch or so minimum, a little more here and there) and seasoned liberally with Kosher salt, onion powder, a bit of garlic powder, some Hungarian paprika, rough ground black pepper, and a little cayenne.
I have an MES 30 with mailbox, so to fit the brisket in I cut it in half, leaving one relatively thin piece and one thicker piece with the cap on it.
Preheated MES to 225 and put the meat in, with a 13x9 pan below filled with 16oz Diet Coke and a bit of water; AMPS maze with pecan pellets in the mailbox.
I started this about 5PM, checked again about 8:30, and then let her run through the night, set to turn off at 5:30 AM.
Next morning, at 5:30, the MES had just shut down, in theory, but was showing 207 chamber temp. So maybe I miscalculated the time and it turned off a bit earlier than I planned, given the 207 chamber temp. On the plus side, the AMPS was burned through - 100% consumption of all that pecan, so that looked good. I have learned that in my setup at least, filling the AMPS maze up to the top of the mesh, especially at the ends where the maze turns direction, is critical to getting it to burn all the way through without messing with it.
BUT - despite 12 hours of smoking at 225, a quick check showed IT about 150-155 on both pieces. How could this be? Well, I guess because brisket is brisket and it does what it wants.
So I pulled them out, put them on a baking sheet in the oven at 225, and let them go another 4-5 hours until they hit 190+ for the IT. A fair amount of additional fat rendered out, and they ended up very flexible, so I knew they were done. Interestingly, there did not seem to be a plateau at the 160-170 range; instead, the temp rise was fairly steady from ~150 up to 190+. So I wondered if they HAD passed the plateau during the overnight smoke, and then cooled back down due to some screwup on my part in setting the MES timer. But its hard for me to believe I was that far off....
Anyway, we wrapped them in foil and a towel, into the cooler to rest for 3-4 hours, then out they came. Nice dark crust, and very easy to slice up. The thick end with the cap had not gotten quite as high IT when I pulled it and in the thick piece you could see a little of the gray collagen still in place, and could feel the difference when slicing/chunking it up. The thinner areas pulled apart just about perfectly.
We poured the fat/juices from the 9x13 pan, let the fat solidify and removed that, then heated up the juices in a saucepan with some ketchup, water, a little brown sugar and apple cider vinegar, and maybe something else but I forget - it was just a quick freehand approach to a finishing sauce, and it turned out really nicely.
Results: really tasty brisket with a nice (not too heavy or powerful) sauce, I'll definitely be doing these again.
I think the key lessons learned, for me, are:
1. Brisket varies, temps vary, etc., and checking IT and cooking to the desired value (I used 190-195 just because I like the tender, pullable form more so than the firmer sliced style) is the ONLY reliable way to know when you are done. Leave yourself plenty of extra time for cooking in case you need it, the foil/towel/cooler method lets you keep the cooked brisket for quite a while before slicing and serving.
2. Next time around I would probably try separating the cap before smoking, to get more consistent thickness, although you'd need to pull the cap off sooner (I think) because at least on this brisket the cap was pretty thin.
3. Make uses of those pan drippings, the finishing sauce was simple and tasty, and not too greasy because we let the fat separate out first.
4. I think that other than TIME to get to temp, brisket is pretty forgiving and you could do just about anything as far as seasoning and it will still taste great.
Anyway, those are just my impressions from the first go around, hopefully they will be helpful to others just as this forum has been for me.