Corned beef brine:
12 cups water
1 1/2 cups Morton's kosher salt (Do not use table salt or other fine salt unless you adjust the amount of salt used. Using 1 1/2 cups of table salt will be WAY too salty.)
1 cup packed brown sugar
4 Tbsps whole peppercorns
1 Tbsp whole allspice
1 cinnamon stick, halved
2 tsp whole cloves
2 tsp whole mustard seed
2 tsp whole coriander seed
1 tsp whole cardamom pds
1/2 head garlic, cloves should be separated and smashed, but do not need to peel
1 oz sodium nitrate (optional, if you care about the meat staying pink. I leave it out)
Mix salt and sugar in water until it is dissolved. Heat the water if you want, but make sure it is cooled completely before you put the meat in. Make sure you are using a non-reactive pot, like stainless or enamel, or plastic sealing bag to brine in. I use a large enamel stock pot. Put the brisket down in the brine and weight it down to make sure it stays completely submerged in the brine. I use a plate. The larger the cut of meat the longer it needs to brine. A whole brisket will take 4 weeks. Since I'm doing the other half of the brisket from Thanksgiving I just leave it to brine for the 4 weeks between Thanksgiving and Christmas.
There are several methods for cooking the corned beef. Last year I slow simmered it in clean water, not the brine water, until it was tender. You can roast it in the oven, grill it or smoke it (becomes pastrami). Cooking low and slow in the key to making it tender though. 250 - 275*F on indirect heat until internal temp is ~190*F.