Bring water, kosher salt, sugar, sage, basil, garlic, peppercorns, and bay leaf to a simmer in a large pot over medium-high heat; cook, stirring occasionally, until salt and sugar dissolve completely, about 20 minutes.

Remove from heat; cover and let steep for 20 to 30 minutes. Set pot in an ice bath and stir occasionally until brine cools to room temperature, 20 to 30 minutes. Refrigerate until fully chilled before using, at least 1 hour.