Gather all ingredients.

Combine vegetable broth, kosher salt, brown sugar, peppercorns, allspice berries, and candied ginger in a large stockpot over medium-high heat. Stir to dissolve sugar and salt; bring mixture to a boil.

Remove from the heat and cool to room temperature. Cover and refrigerator until well chilled, at least 4 hours.

Remove from the refrigerator and add water with ice chunks, apple and onion slices, cinnamon stick, rosemary sprigs, and sage leaves. Stir in remaining 1 cup water and brine is ready to use.