Making Salumi is a labor of love. It takes time and patience, but it's almost always worth the effort.
That said, there are some basic practices that make a huge difference in the texture and flavor of the finished dry sausage. These basic practices start in the actual preparation of the meat in the very beginning and have a noticeable impact on the quality of the finished product almost two months later.
Start with cold meat, and keep it cold throughout the process
This is probably the most important of all factors and affects the texture and drying of the product. In principal, the temperature of the meat being ground, mixed with the cure, and the stuffed into the casing determines the way the meat binds together and forms the finished sausage. The proteins in the meat need to be extracted to bind the sausage together and give it the grain and texture of dry sausage.
Grinding plate size
The size of the grinding plate determines the texture and drying pattern of the finished sausage. The larger grind results in more even - and faster - drying. If we bite into a bologna or a hot dog, we can't see the particles, nor do we get any distinct texture of the meat that was used to make the product. Bologna starts out as a creamy paste or sometimes a liquid that is then cooked to a solid. A dry-cured sausage like a dry salami is not cooked, so the particles of meat retain their character and texture.
During drying, the moisture from inside the sausage has an easier time migrating through a larger particle maze than a tighter small particle maze, thereby drying more evenly.
Fermentation humidity level
The stuffed sausage should be placed in a space that is relatively humid or at least does not have any direct airflow blowing on the fermenting chubs. This will ensure a more even drying pattern.
After the soon-to-become dry sausage is stuffed, it needs to ferment so it can develop that distinct and prized salami flavor. During fermentation, the mixed-in starter culture will multiply and ferment the meat, lowering its PH level and giving it a tangy flavor. Starter culture needs moisture to work. If the outside of the sausage begins to dry too quickly during fermentation, the starter culture will not be able to ferment the meat that is on the outside of the chub, and the result will be an uneven drying pattern and a hard rind on the outside.
Fermentation finished, some drying occurred but acceptable.