1 1/4 C salt (or 2 C Kosher/coarse salt)
1/2 C brown sugar
1 gallon vegetable stock
1 Tb black peppercorns
1 Tb allspice berries
1 gallon ice water
Put 1st group of ingredients in large pot, bring to boil, remove from heat and allow to cool. Pour in ice water and stir to combine.
Put a 'brine bag' (if you can find them and/or are willing to pay a ridiculous sum of money for said bags) or a hefty bag in the bottom of an ice chest. Put the turkey in the bag. Pour the brine over and tie up the bag. Add ice packs and leave it alone for the day. Carefully turn the turkey before going to bed and refresh ice packs. The next morning, remove bird, rinse, and roast as usual.