Ah,
I should add: beside the normal bottle (containing water).

And an explanation with pictures:


During summer, on the way up to our sleeping place (on the photo is a colleague of me). With ropes, 2 iceaxes, screws and all the other stuff some additional weight doesn´t matter any more, especially if the way up to the sleeping place only take 3-4 hours.


Sleeping place, in the background on the left the target for the next day. Anything not needed (sleeping bag, stove, the empty bottle) is left behind and picked up later after returning from the top.

Bringing up a wine and drinking while watching the sun go down is worth carrying the extra weight.

Alex