Preheat espresso machine boiler and run hot water through the empty portafilter for several seconds to heat the portafilter and group head. For best results, taste and discard first and second shots.
Tare your portafilter on your scale. On a super fine setting, grind enough coffee to fill portafilter with approx. 16 grams of grounds. Your grind should look like smooth powder and should stick together when pressed between the fingers. If no scale is available, overfill portafilter, bump the side of the portafilter two to three times with your hand and refill with grounds. Using your finger, swipe grounds north, south, east, and west to distribute evenly in portafilter basket. Again, using your finger, swipe off any excess grounds flat across top of portafilter. Using your tamper, press straight down with medium pressure to make a level compact surface.
Insert and lock portafilter into grouphead and pull your shot. Place a shot glass on your scale and tare to zero. If possible, pre-infuse for 6 to 10 seconds then pull the shot until the scale measures 32 mL of espresso. If no scale is available you should stop your infusion once you see the stream begin to ‘blonde.’
Use the first two to three shots as a gauge then, adjust and readjust your grinder and until you are able to pull your shot in around 27 seconds. Adjust dose, grind, yield, and time to your equipment and taste.
Remove portafilter from grouphead and knock out the spent puck. Then wipe portafilter with a clean bar towel. Repeat steps 1-5 until you and your friends are thoroughly caffeinated, or until ‘the fog’ subsides.
For a more in-depth explanation of how to dial-in your espresso check out this