I have spent several years learning how to great pulled pork on by barbecue pits. When I first started cooking pork butts on my smoker my results were about the same as other folks were getting using crock pots. This was frustrating to me as I was doing so much more work but not getting better results. However, I kept reading and practicing and now produce a far superior product. I thought others might want to learn from my past mistakes so I am giving some tips to start you down the path to better pulled pork.
It is important to start with the proper cut of pork which is the Boston butt. The butt comes from the top part of the hog's front legs, something akin to its shoulder. This cut has the perfect balance of meat, fat and collagen to stay moist while slow cooking. If you try making pulled pork with a loin the lack of fat and collagen will result in meat that is dry by the time it is fall apart tender.
Once you have a pork butt you need to prepare it properly. This was the step that took me the longest to understand. The butt will usually weigh between five and six pounds but have a very low surface to mass ratio. That is, there is a lot of meat but very little is exposed on the surface. If all you do is season the surface of the butt with a dry rub and throw it on the smoker you will get a product that tastes great on the surface and is extremely bland in the middle.
To season the inside of the butt I like to inject it with a combination of apple juice, chicken broth and dry rub. Typically I will mix four ounces each of apple juice and broth and stir in a tablespoon of dry rub. I inject the butt all over with as much of the solution as it will hold. It is important to use an injection syringe with large holes so they do not get clogged with any dry rub particles.
The apple juice adds sweetness while the chicken broth brings some savory components but more importantly, salt. You are essentially injecting the pork with flavorful brine. You can obviously make the mix sweeter or saltier as desired but this is a great starting point.
It is important to let the pork rest in the refrigerator at least four hours to let the injection evenly distribute throughout the meat. Once you try making pulled pork from an injected butt you will be a lifetime adherent of the technique.