Coffee bags. You buy them at the grocery store or wherever you can buy tea bags. It's real coffee (not instant) in a tea bag, you boil the water, toss in the bag, let sit for a while (way longer than tea if you like a strong brew), and enjoy fresh-ish coffee. Worked for me. The bags are sealed in plastic wrappers individually. Keeps them dry and fresh enough to be convincing. I'm sure there's a way to make your own prior to a tour if you like a certain type of coffee and prefer to grind it yourself.