The pork belly should be cut into cubes no larger than 1×1 inch dice. Place them in the freezer for 30-35 minutes before moving on. The pork belly should be slightly frozen. If not it will break down too quickly in the grinder. Also place the grinder attachments in the freezer as well, this will help keep the pork belly cold.
Assemble the meat grinder with a 1/4th inch die on the end and begin grinding the pork belly.
Place the pork belly in a stand mixer with a paddle attachment.
In a small bowl mix together the Bactoferm and distilled water.
In a separate bowl, mix the salt, paprikas, sodium caseinate, and prague powder together and place them aside.
Mix the meat on low in the stand mixer for 30 seconds.
Add the dry ingredients and mix for another 30 seconds.
Add the Bactoferm and water along with the wine. Mix on low until the pork belly starts to become opaque and stick to the sides of the bowl, this is the sign of a properly emulsified sausage. This should take about one minute.
Increase the speed of the mixer to medium high and mix for 30 seconds, at this point the sausage will be ready.
If you have a sausage press that would be the ideal way to add the ‘Nduja to the umai bags.
If you don’t have a sausage press add the sausage mixture into a pastry bag with a 3/4th inch tip.
Invert about 4 inches of an umai bag onto itself and fit the Umai bag onto the end of the pastry tip.
Hold the umai bag onto the end of the pastry bag and begin filling the casing, take your time with this as it is easy to pop the bag and or not fill it enough, leaving air bubbles inside the sausage.
Use the zip-ties that are included with the umai bags and double zip-tie one end of the bag. Work out any large air bubbles that may be trapped in the bag but do not worry about any small pockets of air.
Zip tie the other end of the bag as close to the meat as possible.
Hang the ‘Nduja to ferment for 5-7 days at room temperature (60-65°F).
The umai bag will begin to pull away from the sides of the ‘Nduja as it dries. This is a good sign.
Once the ‘Nduja has finished drying it can be served or added to just about anything.
The ‘Nduja can be stored in the refrigerator for up to a month.