When you inject meat with a curing brine, the amount of nitrite going into the meat depends on two things: the strength of your brine and how much brine you inject. A brine designed for a 10% injection cannot automatically be used for a 20% injection.
These calculations apply to Cure #1 containing 6.25% sodium nitrite, used for injection-only curing. Check your product’s label before calculating.
PPM means parts per million. In this calculation, 150 ppm means adding 150 milligrams of sodium nitrite for every kilogram of meat. FSIS bases injected nitrite calculations on the meat’s original weight before injection, called its green weight. Do not include the added brine in that meat weight.
Cure #1 is only 6.25% sodium nitrite. Therefore:
1 gram of Cure #1 contains 62.5 milligrams of sodium nitrite.
The FSIS handbook lists 200 ppm as the maximum ingoing sodium nitrite level for pumped or massaged cured meat and poultry products other than bacon.
Bacon is a separate case. The standard federal provision for injected bacon specifies 120 ppm sodium nitrite plus 550 ppm sodium ascorbate or sodium erythorbate, with specific lower-nitrite alternatives. Do not use the examples or chart below for bacon.
Your injection percentage—or pump percentage—is the amount of brine added compared with the meat’s original weight.
For example:
|
Original meat weight |
Injection percentage |
Brine added |
|
10 lb |
10% |
1 lb |
|
10 lb |
20% |
2 lb |
|
10 lb |
30% |
3 lb |
Weigh the same piece before and immediately after injection, unless your validated procedure specifies a drain time:
Pump % = (weight after injection − original weight) ÷ original weight × 100
Measure actual weight gain. Brine that leaks onto the worktable is not retained in the meat, and the amount loaded into your syringe does not necessarily equal the amount retained.
This is an important distinction:
Complete brine weight = water + curing salt + regular salt + sugar + all other ingredients.
For Cure #1 containing 6.25% sodium nitrite:
Cure #1 needed, in grams = complete brine weight, in grams × target ppm ÷ (625 × pump percentage)
Enter the pump percentage as a whole number: 20 for 20%.
The curing salt is included in the complete brine weight—it is not added on top of that total.
Suppose your recipe calls for:
Your calculation is:
1,000 × 150 ÷ (625 × 20) = 12 grams of Cure #1
Your other ingredients must total 988 grams. An illustrative formulation could look like this:
|
Ingredient |
Weight |
|
Water |
868 g |
|
Regular salt |
80 g |
|
Sugar |
40 g |
|
Cure #1 |
12 g |
|
Complete brine |
1,000 g |
This illustrates the calculation; it is not a complete curing recipe.
If you inject 2,000 grams of meat at 20%, it takes up 400 grams of this brine. That portion contains 4.8 grams of Cure #1, supplying 300 milligrams of sodium nitrite.
300 milligrams ÷ 2 kilograms of original meat = 150 ppm.
The amounts below are grams of 6.25% Cure #1 per 1,000 grams of complete brine—not per 1,000 grams of water.
|
Injection percentage |
At a 150 ppm example target |
At the 200 ppm ceiling |
|
10% |
24.00 g |
32.00 g |
|
15% |
16.00 g |
21.33 g |
|
20% |
12.00 g |
16.00 g |
|
25% |
9.60 g |
12.80 g |
|
30% |
8.00 g |
10.66 g |
|
35% |
6.85 g |
9.14 g |
|
40% |
6.00 g |
8.00 g |
Values are rounded down to 0.01 gram. Use the unrounded formula when scaling larger batches. The 200 ppm column illustrates the limit; formulating at that limit leaves no room for weighing or pumping variation.
Notice that a higher injection percentage requires a weaker brine to deliver the same nitrite dose.
There is no single exact percentage of water weight that works for every brine. Salt, sugar, and other ingredients increase the total brine weight and change its concentration.
If you already know your water and other ingredient amounts, use:
Cure #1 needed = weight of everything except Cure #1 × target ppm ÷ [(625 × pump percentage) − target ppm]
For example:
1,120 × 150 ÷ [(625 × 20) − 150] ≈ 13.60 grams of Cure #1
That equals approximately 1.36% of the water weight for this particular formulation. Change the other ingredients, injection percentage, or nitrite target, and you must recalculate.
The calculation method comes from the FSIS Processing Inspectors’ Calculations Handbook, particularly printed pages 12, 19–21, and 76–82.
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