I'll try.
Assume you are using 100% nitrite - not cure #1 -
real 100% nitrite,
no salt or anything in it,
just nitrite.
If you add
1gm of it to 999gm of water, you'll have
1000gm of brine - that's one in a thousand parts nitrite (1/1000). But we want to know what that is in Parts Per Million. Well, as a million is 1000 x 1000 we just multiply by 1000 to get the answer. So our 1gm nitrite to 999gm water is 1000PPM nitrite.
Ah, but that's the brine, we want to know what's in the meat. If we have a piece of meat that weighs 1000gm and we want to pump it at 10%, the amount of grams to inject will be 1000 divided by 10: that's 1000/10 =
100 gm of brine.
When we've done this our meat may have 100gm of brine in it but this brine will only contain 0.1gm nitrite -
our original brine had 1gm nitrite in 1000gm of the brine, our 100gm injected is a tenth of the original and so contains a tenth of the nitrite
So we've got 0.1gm of pure nitrite in 1000gm meat. We already know that to calculate the PPM we just multiply by 1000 which is 0.1 x 1000 = 100PPM.
In reality the calculation is done like Oddley did the corned beef one above:
Oddley wrote:Corned_Beef.pdf
grams premixed cure × % Nitrite in mix × % Pump × 1000000
----------------------------------------------------------------------------- = PPM
100 ×100 × Weight of Brine
60 × 6.25 × 15 × 1000000
---------------------------------------- = 216 ppm
100 ×100 × 2600
Our example would be:
1 x 100 x 10 x 1000000
---------------------------------------- = 100 PPM
100 x 100 x 1000
You will note that the weight of the meat doesn't even enter into the calculations. Why? Well, because we inject at 10% of the
meat's weight, the ratio of cure to meat will be the same for this brine irrespective of the meat weight. e.g 2000gm of meat would be injected with 200gm of cure containing 0.2gm nitrite. That's exactly the same as 0.1gm nitrite in 1000gm meat, so it would still be 100PPM.
I hope this clarifies rather than confuses.
Phil