Bulleit Bourbon uses only the highest quality ingredients and follows the 175-year-old recipe of Augustus. Bulleit Bourbon is produced with a high rye content and proprietary grains and yeasts. Rare among bourbon producers, Bulleit Bourbon has its own Grain Division, which acquires distiller's grade grains grown to Bulleit's specification. The high level of rye content creates the dry, clean flavor. In true bourbon fashion, only limestone-filtered water is used. -bulleitbourbon.com