Combine all the dry brining ingredients, minus the sugar and salts, together in a bowl and stir to mix. In a large pot, filled 3/4 full with water, add the sugar and both salts and stir to combine. Stir in half of the brining mix. Bring water to a simmer and stir till sugar and salts are dissolved.
Add the brisket!
Remove pot from heat and allow brine to come to room temperature. Then add the brisket, making sure there is enough brine so the beef can fully submerge.
Cover brisket with a heavy plate or even a foil wrapped brick so the it stays submerged in the homemade corned beef brine. Cover, then place in the fridge. Rotate the brisket every day for 4 days.
After 4 days, it's time to cook the brisket and make authentic, homemade corned beef! Simply remove brisket from the corned beef brine, and rinse off all the lovely seasonings and spices that have accumulated on the meat.