Real coffee outdoors, the Italian way 
For real coffee outdoors I carry one of these ( the smallest one shown):
A 1 Cup 'Vespress' Stainless Stovetop Espresso Maker. Makes 1 demitasse, 5" tall overall, heat resistant handle, stainless steel body, very tough, made in Italy. The grounds go into a carrier inside and as the water turns to steam it passes through the coffee grounds and out into a receptacle in the top part. It means no messy grounds like other coffee makers too. These type of coffee makers are quite common in French hypermarkets and you can get them (and other makes) online in UK.
The smallest one which makes superb expresso coffee or mix with milk etc. Because they work under pressure the water boils faster I find and keep it warmer longer for a second cup. The taste is also better this way ( like a proper expresso machine) I also have used it for tea small to carry. Not essential but a real moral booster 
I timed a 100ml amount of cold water in mine over a Trangia burner ( indoors in the kitchen). I place the burner centred on a Trangia pan as a base then place the wind shield over it and place the expresso maker on the hole where you usually put the burner. This gives a good distance from burner to expresso maker bottom. I had a piping hot expresso (remember the water is turned to steam under pressure like a pressure cooker and passes through the grounds) in 2 minutes 15 seconds.
For real coffee outdoors I carry one of these ( the smallest one shown):
A 1 Cup 'Vespress' Stainless Stovetop Espresso Maker. Makes 1 demitasse, 5" tall overall, heat resistant handle, stainless steel body, very tough, made in Italy. The grounds go into a carrier inside and as the water turns to steam it passes through the coffee grounds and out into a receptacle in the top part. It means no messy grounds like other coffee makers too. These type of coffee makers are quite common in French hypermarkets and you can get them (and other makes) online in UK.
The smallest one which makes superb expresso coffee or mix with milk etc. Because they work under pressure the water boils faster I find and keep it warmer longer for a second cup. The taste is also better this way ( like a proper expresso machine) I also have used it for tea
small to carry. Not essential but a real moral booster I timed a 100ml amount of cold water in mine over a Trangia burner ( indoors in the kitchen). I place the burner centred on a Trangia pan as a base then place the wind shield over it and place the expresso maker on the hole where you usually put the burner. This gives a good distance from burner to expresso maker bottom. I had a piping hot expresso (remember the water is turned to steam under pressure like a pressure cooker and passes through the grounds) in 2 minutes 15 seconds.
