Fresh Coffee on Shabbos

I am a brewed coffee snob, and HATE instant coffee ever since I learned how to make drip ground coffee. I have a solution. Make double strength brewed coffee just before Shabbos and put it (black) in a thermos which is preheated with very hot water, then spill out the hot water and replace it with the coffee. The next day,pour out half a cup of coffee from the thermos, add hot water from the urn in the proper manner, and you have brewed coffee. The double strength of it gets diluted to normal strength with the added hot water. If you do this is the summer time when Shabbos is later, the coffee might even be piping hot from the thermos early in the morning.It’s making coffee “sense” just like for tea, and it’s real coffee.