To make my famous GI Field Coffee you begin with 20 gallons of potable water from the water trailer. It's best when it's carried through a rice paddy knee deep full of water or a hot, steamy jungle. Bring it to a boil in a kettle over a standard issue field mess gasoline operated burner — preferably in the early morning darkness so as not to give your position away to the enemy. If you survive the lighting of the stove, you proceed to the next step.
When the water boils, stir in two, 2-pound cans of ground coffee (it was probably Maxwell House coffee in an olive drab can). Depending on how strong the men like it you may adjust the amount upward or downward to suit their tastes. Once thoroughly stirred, lower the stove's setting until the water simmers. Cover and let simmer for about 5 minutes. Remove from the stove and add slowly one quart of cold water in a circular fashion starting in the center and working outward. This step takes the grounds to the bottom of the pot. Be careful not to disturb the brewed coffee but gently ladle the coffee from the top downward into another container. Preferably a coffee urn. Leave the little bit of coffee remaining in the bottom of the kettle behind. It contains the grounds.