Reviews Virtual Water: Tackling the Threat to Our Planet’s Most Precious Resource by Tony Allan Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Science News September 9, 2011 at 10:43 am Learn why it takes 140 liters of water to make a cup of coffee in this exploration of the water use hidden in everyday life. I.B. Tauris, 2011, 368 p., $18