Anyone know if there is an appreciable difference between curing salt #1 and curing salt #2? I know the #2 has sodium nitrate but that breaks down to sodium nitrite which is the basis of curing salt #1. When to us one over the other?
Yes there's a big difference...they're intended for different purposes.
In a nutshell...cure #1 is intended for short term curing and cure #2 in intended for long term dry-curing.
The cure #1 formula is pretty much standard... 93.75% salt and 6.25% nitrite.
There are at least three different cure #2 formulas here in the US of A....
6.25% nitrite and 1% nitrate. (SausageMaker)
5.67% nitrite and 3.63% nitrate. (Butcher & Packer)
6.25% nitrite and 4% nitrate. (Allied Kenco)