I've always been under the impression that air dried sausage needs 2-3% salt for safety reasons. 2 percent I understood was the minimum.
But I've recently been looking at air dried sausage/salami recipes by Len Poli and also some from the Charcuterie book (Ruhlman and Polcyn) and they seem to use less than this. For example, this sopressata recipe uses 1.63% salt:
http://lpoli.50webs.com/index_files/Salami%20soppresata%201.pdf
And the sauccison sec recipe from Charcuterie uses 1.77% salt.
Am I missing something here? I know there's not a defined amount of salt that makes food safe and that it's a sliding scale, I was just wondering if my previous understanding of 2-3% was incorrect...