Dave - I like the simplicity in your response. I want to clarify for myself and others that you are talking about a dry cure; i.e. not a water emersion cure. Right?
Dry cure is where you rub salts, sugars, cure and on occasion, spices etc. into the exterior of the meat... It is usually refrigerated for about 2 weeks for the nitrite, salt etc. to be absorbed, while inhibiting bacterial growth.... Then it is usually rinsed, dried, spices re-applied, and on occasion, depending on the method and cut of meat, additional salt "maybe", additional cure "maybe".... (in some recipes, salt, cure are applied in a 2 step process)...
The meat can be tied / trussed and hung in a chamber / garage / basement / cave where the temperature and humidity and air flow are conducive to very slowly drying of the product..
Temp usually around 50 def. F and humidity around 78-80% for a product that will not case harden... That is where cure #2 plays a part... natural bacteria in the meat break down the nitrate into nitrite to continue protecting the product.. (so they say)... Then in a period of time, when the meat has lost a certain percentage of water, (low enough so bacteria will no longer grow and the salt that has been applied, increases in % to stop bacterial growth... you have a shelf stable product that no longer needs refrigeration...
Let me explain how the salt % increases... 3% initial salt on a hunk of meat.... the meat loses 35% weight over a period of time... The meat is now 65% of it's original weight... 3% salt / .65 becomes 4.6% salt, if I did that calculation correctly... if not, correct me please..
Someone, other than bloggers, has figured out the appropriate numbers and recipes for all this to be safe...
Anyhow, that's my understanding of a dry cure... could be called other names in other places...
Now a "dry brine/cure" is a name associated with curing meats in a zip bag, in a refrigerator, we have used on this forum.... apply the salt, sugar, cure and spices to a hunk of meat... place in a zip bag, in the refer for a few weeks... as the meat weeps moisture, it is captured by the bag and no chemicals are lost... they are re-adsorbed / absorbed into the meat to insure a safe curing cycle... or something like that... The meat, effectively, is being cured in it's own brine...
OK.... This nitrate being converted to nitrite reaction... It has been documented, somehow, in the last couple hundred years, that the reaction of naturally occurring nitrates in "SOME" salt deposits is responsible for the death of "botulism" is meats that were salted and hung up to dry.... (when folks in Europe were practicing this art of charcuterie).. Somehow, folks figured out that "maybe" a naturally bacteria in the meat was responsible for this reaction of nitrates to nitrites since nitrates has no effect on bacteria....
I have no idea how they figured out that chain of events.... How they determined a bacteria was responsible for the chemical reaction... but anyway, since that crap was figured out, nitrites has been put into meats and botulism, seemingly, has a preventive medicine...
Now, for the nay-sayers out there, bring proof that the above supposition is in error, other than just saying..... "It ain't so"..... or there's no proof...
Nitrite and Meat Curing - Iowa State University
Nitrate (NO3-)
•Insignificant by itself
•Contributes cured meat properties only after reduction to nitrite
•Reduction is not easily done by chemical means in meat systems; typically requiring a bacterial culture with nitrate reductase activity
•May be important in dried products (hard salami, hams, etc.)