I copied this off the net. Looks involved...
Dry curing is a whole new world. I myself use a converted wine fridge with a temperature controller and a few lbs of humidor humidity beads to control the humidity around 70-80%. For what you are suggesting I would recommend using a freeze dried bacterial culture, specifically a Chris-Hansen culture like T-SPX. The purpose of the culture is to introduce a good culture to help keep the bad bacteria in check and to aid in the fermentation process.
Ideally, when I ferment salami, I place it in my chamber and set it to 20°C and place two wet towels in to bring the humidity up to 90-95%. Depending on the recipe, I usually ferment for 72 hours or until the PH reaches 4.8 (a tester is crucial or even paper strips can work).
During this time I sometimes will spray it with a white penicillin culture to promote good mold growth. If cold smoking I skip this process and smoke it after fermentation (cold is the way to go, you are not cooking it) and then after smoking I will spray with mold or not. Depending on the final product you may not want a white mold casing. In that case you will need to regularly wipe down any mold growth with a water/vinegar mix.
Drying temps and times will vary but you are looking at anywhere from 1-3 months drying time, ideally in a chamber or area no higher than 15°C - I myself hang at 12-13°C and the humidity absolutely has to be around the 70-80% range. Any less and you are risking the very present chance of case hardening, where the case dries too fast and the center is then unable to release moisture, basically ruining all your time and effort.
The best way to tell when the salami is done is to go by weight loss. Weigh them when you first stuff them, record that weight, then continue every week or so until you reach anywhere from 30-40% weight loss. This can vary, sometimes 30% loss is enough, sometimes I go higher. I usually know by gently squeezing the sides of the meat to see if it is at the right firmness. This step is only mastered through practice and knowing what firmness is best.
