When I corn beef or a pork butt I do a combination brine (injection + cover brine) like you are talking about.... and here is my process with AmesPhos in the method.
1. Make my brine (it has loads of aromatics) so I simmer it one day and chill overnight.
2. Add Cure #1 to the chilled brine.
3. Measure an amount of brine equal to 10% of the meat weight, then to that I add AmesPhos at the rate of 1.8 grams/pound of meat.
4.
Inject the brine from step 3 into the meat, then bag it and refrigerate for at least 10 hours (or overnight). In my mind, this gives the AmesPhos a bit of a head start, and prevents it from migrating out of the meat.
5. Next I move the meat into my brine bucket and add the remainder of the chilled brine which will cover the meat.
6. The meat now cures for 12 to 14 days, agitating by spinning the bucket daily.
Over the nest 12-14 days, I don't know if some of the AmesPhos is carried away as liquids do their typical exchange, but I'm very satisficed with the end results. If I didn't use so many aromatics in my corning brine, the
daveomak
injection curing method would work just fine. I just like the 'corned' flavor.