Drinking coffee will improve Hunger and Thirst and provide a bonus to Fatigue. A bit of Fatigue will be restored instantly, and Fatigue will be reduced at a slower rate for several hours. When consumed while still hot, it will also provide a bonus to Warmth. Cups of coffee can be found within microwaves.
While the tin of coffee deteriorates over time, cups of coffee do not. So if you have a place to store them, it's wise to make cups of coffee before the tin's condition drops below 50%.