In a large heavy pot, add the milk and the citric acid mixture and warm over medium heat, stirring occasionally, until temperature reads 90°F.
Remove pot from heat and add the rennet mixture. Stir for 30 seconds. Cover and rest for 10 minutes.
While you wait, heat another pot of water to 185°.
Using a long knife, cut the curds in a 1 inch grid pattern.
Place pot back on medium heat and stir gently trying not to break up the curds. When the mixture reaches 105°F, remove from heat and set aside to rest for 5 minutes.
Prepare a medium bowl filled with ice water to rest the cheese. Put on food rated rubber gloves.
Dip a fine mesh strainer in to the pot to remove all the curds.
In the second pot of hot water, rest the strainer with curds for 2-3 minutes. Reheat the curds to a pliable state so you can knead and fold them. After folding for a minute, add the kosher salt. Reheat in hot water when the curds begin to cool. Continue folding until the curds are elastic and smooth.
Form cheese in to a ball and place in ice water bath. Should be cool and ready to eat in a few minutes.
Notes
Unlike the hand-formed method I used, I'd suggest using plastic wrap to form the cheese in to a tight round ball.