to use approximately sixty ounces of water to take into account water that is retained with the coffee grounds in the present invention also taken into account is evaporation from preheat tank 20 about two ounces over 3 4 hours depending upon how well the cover and dump valves are sealed and residual volume in well 56 about two ounces consequently about 64 ounces of water is normally put in reservoir 18 as may be viewed by sightglass 120 if a full decanter of coffee is to be made no manipulation of dump valve 24 is required because it is normally immaterial whether the full decanter contains two or three ounces more or less than anticipated if however less than a full decanter is to be made dump valve 24 is rotated by knob 46 to the desired number of cups to be made as viewed on scale 122 assuming for simplicity of discussion that one wishes to make four cups of coffee knob 46 would then be rotated clockwise to the four cup indication on scale 122 which would lower the inlet end 50 of dump valve 24 below the water surface that amount necessary to drain six cups of water from preheat tank 20 back to reservoir 18 thereafter when knob 48 is rotated to the full dump position 90 u00b0 clockwise from the position of fig1 the water needed for four cups of coffee would be dumped to the transfer tank for making the coffee and subsequently less cold water addition would be required to bring reservoir 18 back up to the fill.