C
curmudgeonly
In short: yes you can scale the brine recipe up or down, as it will still work.
However, there is ambiguity regarding the resulting ingoing NaNO2 concentration.
Pops brine is popular on this site, as it is a simple formulations; it has been used by forum members for over a decade and so it has a reputation for yielding good results.
…but can you scale it?
Let's look at:
-Pops recommendations
-Math
-Regulations
Pops recommendations
Pops has stated “I have cured 1 chicken leg in a 55 gallon bucket of curing brine as well as a whole chicken in 1 gallon of curing brine for the same amount of time, and they both turned out exactly the same! Proving it is NOT the VOLUME, but the CONCENTRATION of the curing brine that is required! Debunking the idiom of having to weigh the meat.”
Granted, he does not specify reducing the volume; but he clearly articulates that volume is irrelevant. Therefore, Pops rules simplify to Number of Gallons Water = Number tablespoons cure#1.
Math
There are two equally valid and accepted equations for calculating the amount of NaNO2 (active ingredient in cure#1) going into the meat during the curing process. The two equations yield drastically different results. The discrepancy lies in the assumptions being made meat weight. The equations are described below, and the tables list results of calculating ingoing NaNO2 for Pops recipe at different volumes for a 1 pounds piece of meat. Note that the two equation do converge when the total brine volume equals 10% of the meat weight.
Equation 1: Equilibrium. This equation assumes that the concentration of NaNO2 equilibrates between the meat and Brine. After curing is complete, the NaNO2 concentration of the brine is lower since cure had to leave the brine to enter the meat. The amount of ingoing NaNO2 changes depending on how much water is used for the Brine.
Equation 2: Pickup/injection.
This equation assumes that the amount of curing agent in the meat is determined by the weight fraction of brine that was pumped into the meat. Assuming 10% of the meat weight gets pumped into the meat, the ingoing NaNO2 concentration does not change with brine volume.
Regulations
The USDA requires that the Maximum ingoing NaNO2 does not exceed 200ppm.
Further they state the there is no regulator minimum, but that 40ppm “is useful in that it has some preservative effect.” (ref. Processing Inspectors' Calculations Handbook, 1995).
As you can see from the tables above, Pops recipe yields a brine that is too strong, or too weak depending which calculation you use.