Making your own corning spices is pretty easy, it just takes time, some special curing salt, and an understanding of how the curing salt process works.
In the example we have below, we started with a large full Brisket, also called a packer trim Brisket, (because that was what was available to us) and trimmed it down to the 5-pound Flat-Half, which we are using for our Corned Beef.
After 7 days for a Brisket Flat Half, and up to 10 days for a thicker cut, like a cut from the round or sirloin, remove from the brine.
You will smoke the Brisket Flat Half until the internal temperature of the beef is 200 degrees F, or when the meat thermometer easily inserts into the Brisket Flat Half with little resistance.