950 litres of water. That’s what’s needed to make one litre of wine according to a new book “The World’s Water 2008-2009” by Peter Gleick. The water is needed e.g. for cleaning and cooling (perhaps they also count irrigation).
1120 litres of water is what is needed to make one litre of coffee, but only some 100 litres for tea (never knew the Brits were such closet conservationists. But on the other hand, they don’t exactly have a shortage of water).
Allegedly, at the time around zero AD the water requirements for a litre of wine was less.