Place the meat grinder parts, stuffer, and a large mixing bowl in the freezer for at least 2 hours so everything stays very cold.

Rinse and soak the hog casings in lukewarm water for 30 minutes, then run fresh water through each casing to remove excess salt.

Grind the chilled pork shoulder and pork back fat together using a medium grind plate; the mixture should remain cold and crumbly.

In a small bowl, combine minced garlic, cayenne pepper, black pepper, smoked paprika, thyme, crushed bay leaves, onion powder, and whole mustard seed.

Add the spice blend and pink curing salt to the ground meat. Pour in 1/2 cup cold water and mix by hand for 3–4 minutes until the meat becomes sticky and binds together.

Load the seasoned meat into the sausage stuffer and slide a soaked casing onto the tube. Stuff the casing with steady pressure, leaving about 1/2 inch free at each end.

Twist the long rope into 4–5 inch links. Prick each link several times with a sterilized needle to release any trapped air.

Arrange the links on a shallow pan and refrigerate for at least 2 hours so the casings can tighten and flavors meld.

Preheat a smoker to 225°F (107°C) using oak or hickory wood.

Place the sausages on the smoker grate and cold-smoke at 225°F for 90 minutes to build color and smoke flavor without fully cooking.

Raise the smoker temperature to 300°F (149°C) and continue smoking until the internal temperature of the thickest link reaches 160°F (71°C), about 60–90 minutes more.

Transfer the sausages to a rack or tray and rest for 15–20 minutes before serving or chilling for later use.