As you know, drip coffee is much different than espresso, not only in the way it is prepared but in the flavor. Espresso is created by forcing very hot water though the finely ground coffee in a quick amount of time. The perfect extraction happens when the espresso is created in about 30 seconds. It is important to have high pressure of the hot water going though the espresso machine - the Nanopresso achieves this by generating 18 bars of pressure with its hand powered piston.
When preparing the perfect espresso, consistency is important. This is where the density of the coffee grounds comes into play, the grounds must be fine enough and packed down uniformly (via tamping) to hold the pressure produced by the espresso machine.
If your espresso extraction is weak, it is likely from too coarse of a grind. If your espresso is too bitter it may be because the espresso was ground too finely and/or the tamp was too dense and the water couldn’t flow freely though the grounds properly. Bitterness comes from too slow of an extraction, meaning the hot water is making contact with the grinds for too long.
How To Tamp With The Nanopresso:
The Nanopresso includes a scoop that is used to measure the amount of grounds that should be used in the filter basket. When you fill the scoop it should be a generous rounded scoop, then bring the filter basket to the scoop, place the basket on top upside down, flip so the grounds transfer to the filter basket. Give the scoop a few taps to be sure all the grounds have transferred. Carefully lift the scoop off the filter basket. If you have the Barista Kit use the included tamp and press firmly, and uniformly on the grounds. If you do not have the Barista kit flip the scoop over and use the underside of the scoop as your tamp. Run your finger around the outside of the rim to remove any extra grounds from the filter basket.
The Puck is key!
The finished puck will be the biggest indicator about whether you have tamped correctly. When the espresso is finished the grounds should be very finely compacted, damp but not watery and it should be easy to remove, intact, in one firm wack. If your puck does not come out all together the grounds were probably not tamped firmly enough or too coarse.
The best part of mastering the perfect tamp is experimenting (and drinking the results!). You’ll know you’ve got it right when your shots are consistent every time. Enjoy!