The concept of tamping is a crucial step when preparing coffee through an espresso machine, in this page I will discuss firstly why it is so important and how to use a tamp.

When preparing espresso coffee the whole aim is to get a quick extraction and get the maximum out of the coffee grounds within the group handle. To help explain the purpose of tamping I will use the picture below to first demonstrate incorrect techniques.

There is a few things wrong with just putting the coffee grounds into the head and doing an extraction. This generally comes down to the fact that because the water is being pushed through the coffee at high pressure, it is naturally going to want to find the easiest and quickest (least resistance) path through the coffee grounds.

In the picture above you can see that when the coffee is put into the group handle it is not put in evenly, therefore there are going to be areas where there is less coffee than others (around the edges for example). This means that the water will find these paths and go through them. Meaning that you don’t extract the maximum amount of oils from the rest of the grounds, or create enough pressure to extract the crema properly.

In the shot above you can see the coffee being ‘tamped’. A tamp is essentially an object that has a circular flat base which fits within the group handle. The aim is for the barista to be able to push directly down to compress the coffee grounds within the filter while levelling them out at the same time. By doing this you eliminate the easy paths for the water, which means that the water will be forced through the grounds at a consistent rate all the way through – therefore maximising the flavours and oils in that small amount of coffee.

One other thing to keep in mind when tamping is that you should apply the pressure directly down, you should be left with level coffee grounds. If you apply the pressure unevenly and one side of the coffee is higher than the other – you will have the same problem as described above where there is an easier path for the water to pass through the coffee.

In the above shot you can see how effective a tamp is at levelling out the coffee grounds, in this picture you can see that the grounds are level across the whole of the coffee basket. There is the same amount of coffee from top to bottom on both the left and right sides, this will produce the best extraction. Below I have provided a few shots of what more professional ‘proper’ tamps look like.

There is also an ergonomically correct technique for holding a tamp, and especially for professional barista’s this should be adhered to otherwise the repetitive motion of tamping can cause problems such as RSI. To use a tamp correctly it should first be picked up in the hand as if you were holding a bicycle handle and support this by placing your thumb on the bottom lip. Here is the process to follow to tamp correctly.

1. Lightly sit the tamp on top of the coffee grounds, don’t apply much pressure. This helps to level the coffee properly.
2. Gently use the rounded end of the tamp to tap the edge of the group handle – this loosens any stray bits of coffee
3. Now (holding tamp as described above) apply a firm amount of downward pressure. While doing this ensure your arm is absolutely perpendicular (at right angles) to the bench top.
4. Release the pressure
5. Sit the tamp back on the coffee without applying pressure, and rotate with your finger tips – this polishes the coffee grounds to ensure it is even