Place the bacon in a medium saucepan over medium-high heat. Cook until nearly done. Remove the bacon for other purposes but keep the fat.
Whisk in the flour until starting to bubble.
Add the coffee and water. Bring to a simmer.
Add the butter and bouillon and stir until the butter has melted and the bouillon has dissolved.
Season with salt and pepper to taste.
Let simmer until the desired thickness is achieved.