Trim the fat from the tri-tip using a sharp knife.
To make the brine, pour 4-5 cups of coffee into a ½ gallon pitcher or large bowl.
Add the kosher salt and stir until it is dissolved. Add the cocoa and red pepper flakes and stir well again to make sure the cocoa is dissolved into the liquid.
If the coffee is still warm, it will need to be cooled before use.
Place the meat into a shallow container or even a 1- gallon sized ziptop bag and pour the brine over the meat to cover. Place in the fridge for about 3 hours.
Remove the meat from the fridge after brining. Set the meat aside and discard the brining liquid. There is no need to rinse the meat.
Season the top side of the meat and the edges with Jeff's Texas style rub, flip it over and season the bottom side as well.
Set up your smoker for cooking at about 225°F using indirect heat. If your smoker uses a water pan, fill it up.
Once your smoker is heated to 225-240°F and holding steady, Place the meat in the smoker and let it cook for approximately 2 hours with at least 1 hour of smoke action.
At about the 110-115 degree mark, melt a stick of butter (¼ lb) and stir in 1 heaping TBS of the Texas style rub. Baste the meat liberally with this mixture.
When the meat reaches 137°F or a perfect medium rare, remove it from the smoker and let it rest with foil tented over the top on the cabinet for about 10-15 minutes before slicing or cutting into it.
Slice the meat pencil thick across the grain and serve immediately with plenty of vegetables and sides.