Right on, Mick. But I'd use cold water in a clean pot, boil it up over the coals of a campfire made from either oak or hickory, and toss in a handfull of grounds. Move it to a warm spot and let it brew for a while. When you just can't wait any longer, move it off the warm and put in a tiny pinch of salt to settle the grounds. Pour a cup and enjoy it. No milk, no sugar -- if you want a candy bar, buy a candy bar.

Or just open the c-rats accessories pack, pull out the packet of instant coffee and dissolve it in a canteen cup of water you heated over a pinch of C-4.