For those who are new to espresso making, understanding how much impact comes from the supposedly simple process of tamping can be elusive. But the fact is, tamping matters, and learning how to tamp espresso properly can make all the difference between a good coffee and a truly great one.
It’s important to take care with every stage of the coffee making process – from the grind to the finished shot. In this step-by-step guide we delve deep into the art behind tamping.
Understanding the basics of tamping
What is tamping coffee?
Tamping is the process of pressing the coffee into the portafilter to form an even puck of compacted coffee. It’s a key part of making a beautiful espresso shot.
Why does tamping matter?
Tamping properly makes sure the water flows evenly through the coffee. Badly tamped coffee will lead to overextraction (if it’s too compact) or underextraction (if not tamped well enough). Just like the care we should always take when grinding to the right weight, tamping has a significant impact on the final coffee flavour.
In extreme cases of overtamping, choking may occur, preventing the water from getting past altogether.
The science behind tamping
An espresso is made under pressure, with the water forced through the coffee grinds. As the water passes the coffee, it extracts the oils and flavours that make the drink. Water moving too quickly will underextract the coffee, leading to a weak and under-flavoured drink. Water that lingers too long extracts too much from each coffee particle, leading to a bitter taste.
How you tamp affects how closely the coffee grinds are packed, and thus how swiftly the water passes through the puck.
Tools for tamping
The three essential tools for good tamping are:
- A quality grinder - No matter how practiced you are at tamping, if the grind coming in is uneven and rough, then you won’t be able to compensate. Starting off with beautifully ground coffee is essential. Of course, at Niche we know a thing or two about getting fantastically ground coffee. Have a look at our Niche Zero or Niche Duo coffee grinders; either will produce a single dose grind that gives you the best start for a perfect tamp.
- The right portafilter - From a tamping perspective, the portafilter is the container we’re tamping in. A good quality portafilter will help ensure that the tamped grounds are well-kept, with unblemished sides that hold in the completed coffee puck. If you upgrade your portafilter from the one supplied with your espresso machine, make sure you get one that’s fully compatible as there can be small differences in style and size – it’s important to get one that matches the diameter of your machine.
- A premium tamper for espresso - A key piece of equipment, when it comes to choosing a tamper and there are a range of options:
- Flat tamper - The most common type of tamper has a completely flat base and a handle to grip it. These are perfectly acceptable and remain the preferred type for many professional baristas.
- Puck and palm tampers - Similar to a flat tamper, puck tampers and palm tampers have a lower profile grip, which can improve stability when holding.
- Domed (or convex) tamper - A domed tamper for espresso doesn’t have a flat base, but instead has a slightly rounded base that leaves a slight crater in the puck. Many professionals enjoy the domed tamper, citing that it is better for avoiding channelling at the perimeter of the puck.
- Calibrated tamper - These tampers have an integrated spring mechanism designed to apply the correct pressure when tamping, making tamping easier for beginners.
Additionally, these optional accessories can help improve your tamping:
- A tamping mat - To improve stability when tamping, as well as protecting your kitchen work-surface, a rubber tamping mat for espresso is a simple extra to your set-up. They’re very useful and generally recommended.
- A knock box - Another simple addition to your home espresso set-up, the knock box is a dedicated receptacle to hold the used grounds once the coffee has been made - knocking the portafilter to collect the used coffee. Some tamping mats come combined with a knock box as a dual-purpose accessory.
- A WTD tool - The Weiss Distribution Technique (WDT) tool is a set of needles that breaks up the coffee grinds before tamping. Our grinders result in a fluffy, well distributed grind, which makes WDT optional.
- Scales - Measuring your coffee to ensure consistency when making each drink is an absolute essential. While not directly part of the tamping set-up, having the right level of coffee is important to making a perfect puck.
Step-by-step guide to how to properly tamp espresso
Here’s how to pack an espresso shot in a few simple steps:
1. Grind the coffee
Perfectly ground coffee begins the process. Use your Niche Zero or Niche Duo to prepare the perfect single shot of coffee.
2. Distribute the grounds into the portafilter
It’s important that the grounds are spread evenly into the portafilter. If your grinder doesn’t smoothly release the grounds, you can use a WTD tool to ensure a regular level distribution.
3. Begin the tamp
With a straight wrist, hold the tamp so your thumb and index finger both touch the base to ensure even pressure. Start by pressing down at approximately 15 pounds of pressure (half a full tamp) to form the initial puck.
4. Apply full, consistent pressure
Increase pressure to approximately 30 pounds (13 to 14 kg) and push down to compact the grounds into the puck. Do not rotate the tamper, as this will prevent the formation of an even puck.
5. Release the pressure
With a gentle twist to smooth the surface of the puck, release the tamper.
6. Check the puck
Inspect your puck, which should have an even and undisturbed surface. If you have uneven sides or notice channelling during the shot, then take note for next time.
7. Insert portafilter into machine
Pull your shot of espresso.
Extra: a word on espresso tamping pressure
When talking about tamping, often the talk leads to ‘how much pressure to tamp espresso’ - but how do you measure the pressure you’re tamping?
First, while it is important to tamp with the correct pressure (around 30 pounds of pressure a good place to aim), you also need to use some common sense. You are not looking to hurt yourself and if you’re grunting and sweating trying to push down to get your coffee compacted, then you’re going too far!
It is possible to measure it (though it may make you feel a bit silly). If you stand on a set of bathroom scales while you tamp, you will see your weight decrease as you push down on the counter. In this way, it’s possible to measure the tamp pressure - and if your scales are metric, then 30 pounds is a little more than 13.5 kg.
Note that at a certain point, extra pressure becomes pointless - there’s a limit to how compacted you can make the coffee. Stick to 30 pounds for a professional puck.
A rubber tamping mat for espresso will help a lot, holding the portafilter steady as you increase pressure.
Common mistakes to avoid while tamping
Practice is key to good tamping, which means making mistakes and then learning from them. Your first few tamps won’t be perfect, and that’s just fine - coffee making is an art, which means constant adjustment and refining of your skills.
Some of the most common mistakes to work on include:
- Uneven tamping - If your puck isn’t entirely level, then one side will be more compact than another. This will lead to an uneven extraction and potentially weaker espresso.
- Too much pressure - Go too hard, and you’re over-tamping which will lead to overextraction and a bitter coffee.
- Too little pressure - Err too far on the side of caution and your puck will be loose, resulting in an underextracted watery coffee.
- Inconsistent grind size - Not directly an issue with the tamping technique but part of the coffee making process, you need to ensure your grinder is producing a uniform grind. Messy, variable grinds lead to flavour imbalances in the final shot.
- Poor distribution - Tamping before you have properly levelled the coffee into the portafilter will lead to channelling, with water passing swiftly through sections of the puck and potentially, a heavily underextracted espresso.
Perfecting your tamping technique
Coffee making is also a science, which means having a method and analysing your data will help you achieve that perfect result. Testing and iterating are key to the process.
By experimentation, you will refine your tamping espresso technique each time. Make sure you note the results of each tamp. Measure your pressure and see what difference a lighter tamp has on your coffee; inspect the quality of your puck both before and after extraction, noting if channelling has occurred or if the sides are uneven. Each time, make an adjustment and write down your results.
Remember, to get the most out of your improving tamping skills, you need a grind that’s similarly attuned to perfection. The Niche Zero or Niche Duo single dose grinders offer incredible precision and unparalleled quality, with virtually zero-retention - ideal for achieving professional-level espresso every time.