Sodium nitrate has been used for many hundreds (maybe thousands) of years in sausage making and meat curing. It's still an important part of the process, but we have become smarter about how we use it.
I'll clear one thing up right from the top. Yes, If you make smoked, cooked, or dry sausage you DO need to use a cure. Here's why...
...There's a nasty bacteria called Clostridium Botulinum that causes botulism (a potent and deadly form of food poisoning). This bacteria lives best in temperatures between 40 and 140 degrees F. and likes moist, low oxygen conditions.
That is exactly the environment we provide in our sausage smokers and hot water baths and when we make semi-dry and dry sausages (like summer sausage or salami).
Nitrites prevent the growth of the botulism bacteria, and nitrites are made from the natural breakdown of either sodium or potassium nitrate.
Nitrites also give cured meat and sausage it's pink color and distinctive taste.
Our sausage making ancestors used saltpeter, a form of nitrate (sodium or potassium) to cure their meat. We now know that saltpeter is many times stronger than what is needed for a good cure. Don't use saltpeter when curing your sausage. We have much better alternatives.
Nitrites and Health
There's lots of controversy around nitrite use and possible health problems. Some studies show that nitrites increase the risk of cancer and they recommend reducing the amount of cured food that we eat.
Other studies have proven that we get much more nitrite in our diet from the natural nitrates found in fresh vegetables...more than we do from any cured meat we eat.
The FDA has strict guidelines on how much sodium nitrate or nitrite can be used in commercially made sausage and cured meats, but they are absolutely sure of one thing...
At this time, there is NO known substitute for nitrite in curing meat and sausage.
They feel that the benefits of using nitrite cures far outweigh the risks.
If you decide not to use nitrites, you can still make and eat many great varieties of fresh sausage.
Available Commercial Cures
There are three commercially available cures that I know of. They're all very safe and easy to use but it's important to remember that they are not necessarily interchangeable.
One brand may have a higher concentration of sodium nitrate or nitrite than another so you must use them based on the directions given by the supplier.
Example: Just because one brand calls for a teaspoon in a recipe it doesn't mean another brand will call for the same amount of their product.
Prague Powder #1 is for all cured meats and sausages except for the dried kinds like hard salami.
Prague Powder #1 is 6.25 per cent sodium nitrite and 93.75 per cent sodium chloride (table salt).
Prague Powder #2 is used for dried meat and sausage. It has 1 ounce of sodium nitrite and 0.64 ounces of sodium nitrate in a pound of product. The rest of the pound is sodium chloride.
Both Prague Powder #1 and #2 are used in very small quantities, around 1 teaspoon per 5 pounds of meat (follow supplier directions).
Morton Tender Quick
Tender Quick is very good to use as a rub or in a brine (for making corned beef etc.) but has limited use in sausage making. With Tender Quick the sausage mixture gets very salty before the correct amount of cure is reached.
I have used both Prague Powder and Insta Cure, and they work equally well. Insta Cure doesn't seem to be the same "screaming pink" color as most Prague Powder (it is still pink though), but that is the only major difference I can see.
So, to answer our questions: Yes, we need to use cure if we want safe smoked, cooked, or dried sausage. Sodium nitrate (and the sodium nitrite it produces) isn't evil. Without it, we couldn't have safe (and tasty) cured meats and sausages.