Understanding cure
Using cure to prevent bacterial growth in meat is a science; too much is not good, and neither is too little. There are strict guidelines for using cure, and knowing what information to consider reduces confusion. Curing salts play several roles in helping preserve food and keeping it from becoming rancid.

The Canadian Food Inspection Agency (CFIA) regulates the allowable cure in products. The maximum input level in meat products, besides side bacon, is safe for human consumption of sodium nitrite salts, which is 20 grams per 100 kilograms of meat product, which is 200 mg/kg or 200 parts per million (ppm).

Why cure?
The curing agents in nitrates and nitrites give meat its characteristic red color, help to improve its texture and flavour, and, most importantly, prevent or delay microbial growth and toxin production. Encasing meat for sausage creates the perfect environment for bacterial growth with no oxygen. When heated during smoking, toxins could develop that cause issues like botulism.

What to buy for cure
The CFIA defines the term "cured" as meaning "in respect of an edible meat product, that salt and at least 100 ppm of sodium nitrite, potassium nitrite, sodium nitrate or potassium nitrate, or any combination of them, has been added to the meat product."

The bottom line is that a Canadian cure has the recommended amount of nitrite or nitrate combined with salt. If you go to a website like High Caliber Products, you will find a section on cures with an explanation of uses. The High Caliber F.S. Cure has a 5% sodium nitrite and salt formulation to meet Canadian safety guidelines.  

Nitrite and nitrate

• Insta Cure No. 1 or F.S. Cure and Prague #1 contains sodium nitrite and can be used in sausages, smoking fowl, or fish. The guideline is to use 1 teaspoon for every five pounds of meat.
• Prague #1- Meats that require further cooking to complete the curing process, like sausage, jerky, etc. The #1 is the most common cure for hunters, as the final products are not air-dried; they are finished in a smoker or dehydrator.
• Insta Cure No. 2 is Prague #2, which contains a percentage of nitrate or nitrite. It is used for meats like salami and prosciutto that are cured for longer periods and often air dried.
• Prague #2- Meats that are eaten without cooking. The #2 cure is for meats that need to be cured for long periods and smoked, like a hard salami and ham. They have nitrites and nitrates.
• The #1 is fine for things that call for a cure to act quickly and may see hours of low-temperature smoking. The #2 is used for prolonged curing in meats, such as in dry-curing. Curing salts removes fluid from meat cells, making it difficult for bacteria to form.

Cure simplified
Wet brine

Bernie Krause from Krause & Krause Custom Processors simplified making a wet brine.

1 litre is 1 kilogram

Use 7 kilograms of water and add 680 grams of salt, 112 grams of cure #1, and 150 grams of brown sugar. When you break down the percentages, salt is 9.7%, cure is 1.6%, and sugar is 2.1%.

Dry curing

Dry curing is used on bacon, air-dried hams, and pastrami. A dry cure is rubbed into the meat and then refrigerated for five to seven days to allow the cure to work through the proteins. Goose breast bacon and pastrami, or venison hams, are examples of dry cures you can use.

Weights and measures

Butcher shops use weights and measures to add cures for making sausage and other cured meats, like jerky, because it is crucial to get the ratios right. The easiest way to calculate how much cure, salt, and sugar is required is to weigh 2.5 grams of Cure #1 and 27.5 grams of additional salt (kosher recommended) for a consistent product with the right amount of cure. You can sweeten it up with 20 grams of sugar or another sweetener.

Remember

Use 1 level teaspoon of  #1 cure for every 5 pounds of meat, the same as 2.5 grams per 1 kilograms.

Wet brine: the basic ratio of salt to water for a brine is ¼ cup of kosher salt per 4 cups of water. Kosher salt without iodine is recommended. If you are using fine table salt, reduce the amount to 3 tablespoons.

Make sausage

Cure takes time to work. Add the curing salt to your sausage meat or jerky with the other spices when mixing up a batch of sausage. Place the meat in a refrigerator overnight to let the cure penetrate and work through the meat. The meat is then ready to stuff into casings or smoke or used to make patties, meatballs, or other products that require further cooking.

What cures do High Caliber carry for hunters to consider?

• F.S. Cure (Cure #1) (sodium nitrite 5%) 
• General Cure (sodium nitrite 1%)
• Cure for Dry Salami (Cure #2) (sodium nitrate 5.29%, sodium nitrite 2.94%)

There are also additives and cure accelerators. High Caliber also has some great books to explain recipes and processes for making processed meats:

• Great Sausage Recipes 
• Home Production of Meats & Sausages
• Art of Making Fermented Sausages 

Still confused?
The good news is that companies that prepackage mixes for making sausage and jerky include the cure. Products from Hi Mountain are a good example; every kit has cure and instructions on how to use it. The High Caliber, Complete Spice Units have the correct amount in a small package of cure included in the bag for processed/smoked sausage like pepperoni, smokies, and jerky. However, it still never hurts to measure each time.

For more insight and knowledge on curing, read Brad Fenson's interview with High Caliber's expert, Aaron McLaughlin.