You have probably noticed it in bars and cafés, the barista tamping his coffee before inserting it in his percolator. This gesture can be done with a machine or by hand.
A question of regularity
After filling your filter holder with the right amount of ground coffee, it is very important to properly tamp your coffee. Indeed, the water in your machine will try to find the easiest and shortest way to your cup. It will therefore favour the air holes in your coffee. As a result, there will be under-extractions in some areas of your grind and over-extractions in others. You will then end with a bad coffee.
The tamping allows you to obtain a perfectly smooth cake and to distribute the coffee in a balanced way. The water will flow evenly which will give a homogeneous coffee.
What to use to tamp ?
In many bars and cafés, the tamping device that is integrated in the grinder is used. This allows to always pack in the same way, no matter the barista, but also with the same force. On the other hand, it happens that the diameter of the tamping device is smaller than the filter holder, and therefore the coffee is not evenly tamped.
The best way to do this is to pack by hand with a tamper adapted to the diameter of your filter holder. We offer Joe Frex tampers that fit perfectly with the diameter of the Dedica by Delonghi percolator machines.
How to perfectly tamp ?
When the freshly ground coffee comes out of your grinder, it will form a mound in your filter pan. The first step is to level the ground coffee. Use the back of a spoon or a small stick to reach over the filter and push the grind so that it is evenly distributed.
Then place your filter holder on a packing mat to prevent it from slipping or damaging your work surface. You must then press your tamper on the filter holder respecting the following 3 rules:
- Level: your tamper must be perfectly parallel to the filter holder. You must not lean on one side or the other.
- Compact: In order to compact the filter holder sufficiently, you must apply a pressure of about 15kg. If you are a beginner, we advise you to practice with a scale. Practice using a tamper by pressing on your scale until it shows 15kg. This will help you master the amount of pressure you need to apply.
- Remove: Before lifting your tamper from the filter holder, you should rotate it a quarter turn to avoid leaving grounds on the tamper.
So how do you know that you have properly tamp? Flip it upside down ! If the coffee falls then it was not well tamp however if the coffee holds it's a success