The word tamp would not be part of your normal everyday vocabulary so understanding that it means to “pack down a substance firmly” helps understand how to tamp coffee effectively. Tamping coffee means to press firmly on ground coffee to make it ready for brewing.
Baristas and so-called coffee experts will have you believe that tamping coffee is a very important part of making a great coffee. It’s not.
It needs to be done and you should care about it but only a little bit compared to the other variables that are much more important.
If you absolutely want to fine-tune every single part of the coffee-making process then you can go OCD on tamping and for those of you that want to go down that road we go into detail below.
If you just want to make sure you are tamping correctly then just press down on the ground coffee until it is packed into the portafilter. When you take the tamper out check that the bed of compressed coffee you have created is flat.
You know you have got it right if your double espresso is delivered in about 25 seconds give or take a few seconds either way. The coffee should flow out looking like silky honey.
If the coffee pours out too quickly in say 10 seconds, try tamping a little harder. If the coffee is dripping out and not flowing, tamp a little softer. Keep practising until your coffee is delivered in the window between 23-28 seconds.
Tamping is done in conjunction with a few other important variables and should be the last thing you do when attempting to create the perfect espresso.
Make sure you have all the other things right first before tamping because you could be tamping your coffee perfectly but if something else is wrong then you will not get your double espresso delivered in 25 seconds even if you are the world champion of coffee tamping (there is no such thing before you Google it, it’s really not that important).
These things include how finely you grind your coffee and how much coffee you grind into the portafilter plus the type of coffee you are using and more.
This article explains those things in detail:
1. Make sure the bed of coffee in the portafilter is as flat as possible.
This will avoid “channelling” which is the fancy word for water escaping down the side of the bed of coffee without going through the coffee.
If the coffee slopes one way then the water will find the easiest way out which is on that slope and the coffee will pour out too quickly and you’ll get a watery, under-extracted coffee.
It’s quite hard to see if the bed of coffee is flat by looking at it from above so once you have tamped, keep the tamper in and raise everything to eye level. If it’s not flat you will see the tamper is angled and you can make the necessary adjustment before checking again.
2. Give the portafilter a shake during the grinding process
When coffee is ground into a portafilter it always ends up in a heap and it needs to be evenly distributed to give you the best chance of creating a flat bed of coffee when tamping.
I always shake the portafilter whilst the beans are grinding to avoid a heap of coffee in the middle of the portafilter.
If you shake the portafilter after grinding has finished you almost always end up losing some coffee over the side and it makes the whole thing messy.
I have my coffee grinder set to deliver 18 grams of coffee which for me is perfect and I want to keep it all in the portafilter without spilling any.
3. Hold the tamper correctly
There are two parts to every tamper, the handle and the base. Put the handle in the palm of your hand and wrap your fingers around the handle so that they are touching the top of the base.
It will feel a bit weird to start with, but once you get used to it you’ll see that it helps to create a flat bed of coffee which is important.
4. Use a flat surface to tamp
Some people like to use a tamping mat. It’s a bit like a mouse pad. Either you like them or you think they are a waste of time.
I have tried them and don’t recommend using one. There is nothing wrong with them but in my view, they are a waste of time and don’t benefit the end result. A worksurface is just fine.
Wherever you rest the portafilter before tamping just make sure the surface is as flat as possible.
5. Be consistent
Once you have cracked it try and do the same thing every time. Getting great quality coffee is about doing the same thing over and over again once you have got it right.
6. Try a different tamper
The tamper you are using is almost certainly the one that came with your coffee machine.
Unless you have bought a really expensive machine you may have a cheap and lightweight tamper that is not delivering good results.
I have 3 tampers and I only use one of them. It’s a good weight and it feels good in my hand. It also takes the guesswork out of the equation because it applies 30 pounds of pressure with a spring-loaded mechanism.
Applying 30 pounds of pressure is not essential but it works for me and it helps me to be consistent every time.
Some of cheaper coffee machines come with a plastic tamper. If you have one of those then you definitely need to change it because if you use it properly then it will probably break anyway and you will struggle to get a flat compressed bed of coffee.
You don’t need to spend a lot of money on a coffee tamper and having a decent one makes a difference that is worth the investment.
This is the coffee tamper I use
Here is a short video that explains some more about tamping your coffee: