I am going to smoke my first Boston butt this weekend. I have already applied yellow mustard and some rub wrapped them in plastic wrap and have sitting in the fridge. I have two butts. One weighs about 6# and the other 7#. Do I consider this a 13# butt or individual? I plan on smoking around 205 so I'm trying to estimate how long it will take so i should know when to start. Any suggestions would be great. I live in ga so outside temperature is around 95 during the day and 80 at night. I am also curious on which rack to place them on? I have an OBS 4 rack. I am thinking about using hickory and apple but I also have mesquite and Jim bean also.
Good luck on your first butt, they really take some effort to screw them up so you should be good. I normally cook mine at 225, and normally do two at around 8-9 lbs each and have had them take anywhere from 18-21 hours to finish up. I always plan on them taking longer and can rely on the FTC (foil, towel, cooler) method to keep them hot if they get done early.
I normally place a tray with beer in it on the bottom rack to catch the drippings, then the first but on the next rack up and then the next butt either 1 or 2 racks up depending on whether it fits or not.
I like hickory on pork so I think the hickory and apple would be a good combo. After you are done applying smoke then change the water and rotate the racks, top to bottom front to back. This will help even out the cooking a bit. At this point I normally go to bed and then rotate again and refill the water in the morning.
195 is when I pull mine and FTC them for at least an hour before pulling. Don't worry when the temp stalls for a while, this is normal and it will start going up again eventually.
consider the total weight at 13 lbs and figure 1 1/2 hour per lb cook time at 225 and a stall period is normal i have had 13 lbs get done in 16 hours and other time it took 22