Instants have come and gone, though I think Trader Joe’s Columbian instant would do in a pinch. I’ve tried funnels and gadgets of various sorts. I will not take an espresso maker; too much to fidget with.
A few years ago I found a lightweight, convenient method of taking fresh-ground coffee on the trail and brewing it with as little fanfare and difficulty as possible.
Enter – the coffee sock. No, it’s not a “recycled” tube sock (ack!) It’s a wooden handled gadget with a muslin “basket” which holds grounds through which hot water if poured. Quick on the brew, good on the palate. I can amp the coffee with as many grounds as I like and cleanup is a simple rinse. Occasionally I will use some soap and water to wash out the oils which accumulate.
Viola! Easy, fast, and most of all – effective!