In a medium pot, bring 1-2 quarts (4-8 cups) of water to a boil. Add the salt, sugar, bourbon, espresso, onion powder, bay leaves and garlic. Stir well.
Once salt and sugar are dissolved, remove from heat and let cool until room temperature (or add ice/cold water).
Place turkey in a large stock pot or container (lined with a brining bag if available). Add dissolved brine mixture and top-up with remaining water. Seal and refrigerate for 24 hours.
Remove turkey from brine and pat dry. Let rest out for thirty minutes to an hour before cooking. This will ensure more even cooking.
**Can substitute brining bag for a large tupperware container, or oversized Ziploc bag.
