Marinade: In a bowl, whisk all the ingredients until well blended.
Rub: Combine all in a bowl. Triple or quadruple the recipe and keep the rest in a zip lock bag for future briskets.
Brisket Prep: Cut a hole in the top of the vacuum pack and drain out the blood.
Using a funnel, pour in the marinade, working it around until all of the brisket is covered. You should still have about 1/2 the marinade left. That will be used as a basting sauce when you smoke the brisket.
Patch the whole with duct tape.
Marinate in the refrigerator for up to 2 days--overnight as a minimum.
Remove the brisket from the bag, pat dry.
Determine the direction of the grain and slice a piece across the grain. This will help you later when it comes time to slice and serve--it's more difficult to tell later when the brisket is cooked.
Coat brisket generously with the rub.
Allow the brisket to come to room temperature before putting in the smoker. I place the brisket in a low oven (200 degrees F) while I get the smoker going.
Smoking the brisket: Fire up the smoker according to the manufacture's instructions. Bring it up to 225 degrees F.
Place brisket in smoker at the level of the thermometer, be sure there is not direct heat hitting the brisket.
For the first two or three hours it is best to keep the heat between 190 to 220 degrees. It can gradually get hotter up to a max of 250, but lower for longer is always better. It will take approximately 8-10 hours.
Turn, rotate, and baste every hour. Add wood to smoker every 30 min (as required) to keep the heat at a constant temperature. I use hickory or pecan.
Check the internal temperature, at the thickest part of the brisket after about 8 hours.
When brisket has an internal temperature of 190 degrees F. it's done. If you go much beyond that, the brisket will shred rather than slice. Remove and wrap in aluminum foil. Let rest for at least 1 hour before slicing.
Slice the point off the brisket. There is a natural division of fat between the point and the flat to slice along.
Working with the flat, slice 1/4 inch slices across the grain starting at the starter slice you made before smoking.
Determine the direction of the grain on the point, and slice across the grain just as before.