Bring water and instant coffee to a boil in a medium pot. Reduce the heat after stirring in both brown sugars to the coffee. 3 hours of simmering with 15-minute intervals of stirring. Cool fully after being removed from the heat.
Fill a clean, big glass jar with the coffee mixture. Add the vanilla bean, vanilla extract, and grain alcohol. Place a tight-fitting lid on top.
Allow to sit for four weeks in a dark area, occasionally shaking. Leave a portion of vanilla bean in each bottle after dividing into them.