I bought a free range, local turkey from Diestel Farms this year- 18.5 lbs!
You will need to buy a "brining bag" to hold the turkey and all the brine liquid. You should also plan to have a roasting pan large enough to hold the bird, but small enough to fit in your fridge.
This brine recipe is for roughly a 20 pound turkey. According to the info I've read, you should plan to leave the turkey in the brine for 12 hours or more- so plan ahead!
1. Bring to a boil in a large pan over high heat:
1 LB kosher salt (must be kosher salt, other salt will ruin turkey)
8 C water
1/2 C sugar
2. Now add and stir:
1/2 C molasses
1/2 C lemon juice
1/3 C maple syrup
3 cloves garlic, minced
1 TB fresh ginger, sliced
1-2 tea fresh ground black pepper
3. Let the brine sit and cool down- you don't want to cook your turkey with the brine mixture.
4. Once the brine is cooled, take the turkey out of the wrapper, and remove the internal organs, etc. Rinse turkey. Carefully place turkey in brining bag- you will probably need a partner to help!
5. Pour the cooled brine into the bag. Now pour additional 4 C water into the bag.
6. Seal the bag, removing as much air as possible. Stick turkey back in fridge until roasting time (should be 12 hours or more in brine).