Based on the products I know of from Calabria, 'Nduja seems to be the crown jewel of the regions productions. It's spicy, unique in its texture and is always a crowd pleaser. From the reading I've done and the writings of Scott Stegen on the subject, it appears to be a product derived from using the excess fat produced by the large hogs used in traditional salumi production in Italy, as well as the less desirable cuts such as Lungs, kidneys, etc. It's almost entirely fat (roughly 80%) which is what makes it so spreadable and rich. In this particular batch, I used belly from one of our American Guinea Hogs as the only source of meat and the Calabrian peppers came from Scott's store of the same name as his blog.
The process is relatively straight forward, but does have a step that is atypical to most salumi making that people are familiar with. When making 'Nduja, one of the first steps is to grind the peppers through your grinder. Following the grind, you reconstitute the peppers just enough that the pepper forms a nice paste. This paste will then make up 30% of your total weight of the product and the blend between sweet and hot will determine the end product's final heat level. For this particular batch I went 70% hot and 30% sweet and it was perfect for me.
The final mix of meat and peppers is stuffed into a hog middle, as per the traditional methods, and set to ferment for 36 - 48 hours and then lightly smoked. From there it's hung in the chamber to "dry" for 45 - 60 days, after which it's ready to be consumed. You will obviously lose little, to no weight, as the majority of the product is fat, so you really just have to rely on patience rather than feel and weight.
I have been lucky to taste the pinnacle of 'Nduja made by Luigi Caccamo from Spilinga, Italy. The product they make is amazing and the texture is smooth and the heat there, but a bit subtle for my tastes. Here is a video of the master at work for reference.
With all that being said, I have to say, I prefer my end product to even Caccamo's. The AGH belly is just so smooth, rich and buttery. The heat is right there and rolls on over time and doesn't just slam you in the face. I have to say, this is up there with one of the best products I've ever made, if not the best. I have to say thanks to Scott and Jason for their help and research.