how to operate the Gaggia Esportazione

first step is grinding the beans on the Mazzer Major, which has 83 mm flat burrs and is absolutely sufficient. the grinder has an Auber electronic timer with .01 sec increments. typical grinding time is between 3.8 and 4.2 seconds.
fill the portafilter and tamp the puck. contrary to the requirements of a pump machine a lever machine doesn't need the puck to be tamped very hard. 10 lbs of pressure is more than enough. most important is an even tamp.
lock the portafilter in the grouphead and pull the lever down until the catch sets. this is the pre-infusion stage. water is flowing into the brewing chamber and wetting/soaking the puck.
after pre-infusion pull the lever all the way down and let go. this starts the extraction and the piston spring now forces the piston inside the group head down, which presses the water through the puck.
the lever will go slowly up and the extraction will be finished when it returns to its original top position.
the extraction time depends on the fineness of the grind and to a certain degree on the pre-infusion time. coarser grind/ longer pre-infusion = shorter extraction resp. finer grind/shorter pre-infusion = longer extraction

.
we achieved our best results with 6 seconds of pre-infusion and 46 seconds of extraction.