Why is tamping important? 

Tamping is often neglected in espresso preparation.  The idea is to create a tightly compressed "puck" of coffee that will ensure the water from your machine extracts each shot evenly and consistantly.

The water from your espresso machine is under pressure, so the puck must be hard and evenly tamped.  Water will always follow the path of least resistance, so it is important to prevent paths of lesser resistance in the coffee puck. This will allow the water to evenly permeate the puck and therfore evenly extract each shot of espresso. 

Correct tamping will achieve this.

Poor tamping will result in channelling during the espresso extraction.  This means water will flow unevenly through the puck - so some portions of the grounds will be over-extracted and other portions will be under-extracted. This will result in a watery, bitter and/or sour tasting espresso.

 

Correct tamping technique: 

1: "Dose" your porta-filter with the correct amount of ground coffee. It will be unevenly distributed, so you'll need to use one hand to gently level the coffee.  This is best done by pulling the grounds to one side of the basket with a slightly curled finger, then pushing the coffee grounds back to the opposite side of the basket  until they are evenly distributed.

 

 

 

2: 1st tamp. Hold the tamper so it's comfortable in your hand.  Your wrist should be straight, and the tamper should be a straight extension of your arm.  Compress the coffee with around 2 kilos of pressure. Some of the coffee grounds will rise up the sides of the basket, so gently tap the basket with your tamper to knock the grounds onto the flat puck you just created.

 

 

 

 

3: Finishing tamp. The shape of the puck is already formed, so hold the tamper as before and compress the puck again with 13-15 kilos of pressure (you can practice on  bathroom scales to get a feel for the appropriate force needed to achieve this). Now rotate the tamper for 2 complete turns (720°) while continuing to apply pressure - this polishes the surface.

 

 

 

 

4: Insert your portafilter in the machines brewing head and begin your extraction.


 

Troubleshooting:

  •  Make sure the surface of your puck is level and not on an angle. You can check this by observing your tamper as it rests on the puck in the portafilter. If your tamper stands straight, your puck is level.
  • Tap the basket lightly during the 1st tamp. You do not want to "split" the puck- this will result in an uneven extraction. 
  • Get this technique down to around 30 secs. Your portafilter is hot- if you take to long during the tamping process this heat will adversely effect the flavour profile of your shots.