Aaron,
Good questions, and hopefully Martin will jump in - he's the resident expert! First of all, instead of referencing just my first brined jerky post, look to this one for the adjusted numbers that I now use:
Brined Jerky Part 2Now, the way I keep the calculation straight is that the percentage you are adding is really just a number that will be in the water weight. So, if I have 3000 g of meat, and 3000 g of solution, I am adding 1.5% salt to the solution, to achieve the taste I want. You are correct that the point of the equilibrium brine is that the meat and solution will "merge," and essentially become one unit, equally dividing the solution
. This is achievable with jerky strips because of the thickness, but would take a very long time with larger cuts of meat (like a ham).
The percentage of salt and sugar you add is a "starting point," that may or may not change, after your first attempt. I mean, who talks in percentages? "Yes, waiter, I'd like the fish with 1.5% sodium, please.." Might get a funny look.
So the only way to approach an EQ brine is to try a proven recipe, and adjust accordingly.
What you will find is the ability to get
very consistent results! I use Martin's calculator, and Gregor's too. Whichever one you use, always use the same one, when making adjustments. Whether it shows the percentage in 1/2 the weight, or in all the weight, it will always give you the same results when you modify. Kind of like weighing yourself on the same bathroom scale...it may be off a few pounds, but it will be off the same, every time!
This is a good question, and one I had never really thought about! I just keep it simple, and know that the calculations I use for my jerky (using Martin's calculator) work fantastic!