Mix the salt and Prague powder together.
Cube the lean pork into approximately one-inch cubes. Dice the fatty pork. Mix the fatty pork with 2 teaspoons of the salt mixture. Mix the lean meat with the remaining salts. Refrigerate both for 48 hours
Preheat your smoker to 150-180 degrees.
Soak the casings for 30 minutes in warm water.
Mince the fatty pork or run through a meat grinder with a fine plate.
Mix all the seasonings into the fatty pork.
Puree the fatty pork in the food processor, adding the iced water to facilitate a better puree. In a large bowl, or using a stand mixer, mix the lean pork chunks with the puree until well blended. Stuff the meat into the casings, compress and twist the ends with the extra casing tucked underneath.
Clip the rings or tie off the ends of each sausage, except one.
Put a temperature probe into the center of one sausage and tie the casing as tight as possible with butcher’s twine.
Hang sausages in the smoker, or place on the racks and smoke for three hours.
Increase smoker temp to 225 degrees and continue smoking until an internal temperature of 165 degrees has been achieved.
Cool then refrigerate uncovered for at least 24 hours.
Peel, cut and enjoy!