Brine the turkey: In a large pot, combine the brine ingredients and place over medium-high heat. Bring to a simmer, stirring occasionally, until the sugar and salt have dissolved, 8 to 10 minutes. Remove from the heat and chill, uncovered, in the fridge until cool, about 1 hour. Make ahead: Once chilled, the brine can be covered and stored in the refrigerator for up to 1 week.