Tamping the espresso grounds into the portafilter is in order to compress the grounds so the water will flow through the grounds in an even way in order to extract the maximum amount of flavor. It’s very easy to get wrong in which case you end up with a bad espresso. If you tamp too hard, the water will struggle to flow round the portafilter, eventually it will find the path of least resistance, leaving most of the grounds untouched. The result will be a bitter espresso. If you don’t tamp with enough pressure then you’ll end up with too much of an easy flow of water around the grounds, with the espresso arriving in the cup far too quickly. The result will be a weak and bitter espresso.
However, by using the correct pressure, with firm and even tamping then the water will easily make contact with all the grounds in the portafilter and the maximum and full flavor will be extracted. The result will be a delicious espresso!
The good thing is that learning how to tamp espresso grounds correctly is fairly easy and once you have the technique, you won’t forget it! You’ll also be able to watch how the professionals in your coffee shop do it and you’ll know you’re better at it than them!
Tamping Espresso Grounds
Simply follow the steps below to acquire the perfect tamping technique:
Step 1: Using your burr grinder to dose your portafilter, use your finger to even out the dose. By not ensuring the dose is level within the portafilter, you risk having certain areas of the portafilter more compact than other areas which can have a negative effect on water distribution.
Step 2: Use a high quality stainless steel tamper. Unfortunately, there are just too many espresso machines, even high quality and expensive Italian espresso machines that come with ridiculously cheap and plastic tampers which you should just throw away.
Step 3: Apply the tamper to the portafilter straight on, without an angle. You need the pressure to be applied evenly to the entire surface of the grounds. Many tampers will be slightly smaller than the area of the portafilter. In this case, simply tamp North, South, East and West, twisting each time you move. The pressure should be even throughout, at 30 pounds. You can practice your 30 pounds of pressure with your arm on a bathroom scale. Do this a few times for practice by actually using your tamper on the scale!
Step 4: Inspect your work! You need everything to be nice and even. If not then it’s not a big problem, simply knock the grinds out and begin again.
Step 5: Once you’ve finished brewing your espresso, you can inspect your work. Knock out the grounds onto a surface. They should come out in a single block, or cake. Have a look inside and inspect for channels where the water went through. This most likely means your pressure wasn’t even or you pressed too hard. In reality, if it all comes out in a solid cake mass then your pressure and tamping was probably spot on. Now all you need to do is enjoy your delicious espresso!