Gather the ingredients. Coat meat with pork rub. Combine marinade ingredients in a small plastic or glass bowl. Using meat injection syringe, inject the mixture into several different spots in the pork roast. This will make enough to inject one 8-pound pork butt.
The ingredient combinations for a pork butt injection are endless. Add different liquids like apple cider vinegar, apple cider, BBQ sauce, or Worcestershire sauce. Sprinkle in spices like cumin, cayenne, garlic powder, paprika, and celery salt. Add herbs like dried thyme.
Prepare a batch of pork shoulder rub. Combine all ingredients and mix thoroughly. Place one of the butts in a baking dish or food service pan and inject in 12-16 spots with 1/4 of the injection solution. Pick a spot, stick the needle deep into the meat, and slowly depress the plunger while pulling the needle out, then repeat in a different spot.
In a medium bowl, whisk together the apple cider, water, vinegar, brown sugar, Worcestershire sauce, butter, salt, black pepper, and cayenne pepper until well combined. Fill a meat syringe with the marinade. Place the pork butt in a large pot or rimmed baking sheet and pat it dry with a paper towel.