Letter: That's an awful lot of water in my pint

From Brian Jones, Melbourne, Australia

You quote Charles Denby saying that it takes 50 litres of water to grow enough hops to make a pint of beer (24 March, p 19). I am an avid home brewer and use about 200 grams of hops per 40-litre batch – nearly 3 grams per pint.

A typical hop plant yields 600 grams. On these figures, each plant would require 10 cubic metres of water. If a plant occupies a quarter of a square metre, that implies a water column 40 metres high, around five times the height of the plant.

The editor writes:
• Beer recipes vary, as do estimates of hops' water needs. One source says it took 2746 litres of water to produce 1 kilogram of hops (bit.ly/2gcSSBK).