Step #1 Remove briskets from wrapping & place this in large pot or crockpot.
Step #2 Rinse if you don't like the brine coating.
Step #3 Add contents of 1 spice packet (discard 2nd spice packet or reserve for other use), the beer, peppercorns & bay leaves.
Step #4 Break garlic head apart & peel each clove.
Step #5 Add entire head to the pot.
Step #6 Add enough water to cover the meat by 1 inch.
Step #7 NOTE: the briskets will float, so I put a heavy heat-resistant plate or bowl on top to keep them submerged.
Step #8 STOVETOP: Turn heat to high & bring contents to a boil.
Step #9 Turn heat to a low simmer; cover & cook for 6 hrs or more.
Step #10 CROCKPOT: Set on high cover; cook for 8-10 hrs.
Step #11 When done, using 2 large spoons or spatulas, carefully remove briskets to serving platter & let rest.
Step #12 The meat will be extremely tender, & will easily break apart if you use a meat fork.
Step #13 If using for sandwiches, tightly wrap each brisket in plastic & put in the fridge for 1-2 hrs before slicing.
Step #14 If you want to shred the meat, there is no need to put in the fridge--just cut in thick slices & shred each slice.
Step #15 If serving as corned beef & cabbage, once meat is removed, transfer cooking liquid to large pot (if using crockpot), bring cooking liquid to boil & add vegetables.