Precision Tamper
By Yalcin Akpinar · Food chemist, over 15 years in the flavour industry
A precise tamper, like the Normcore Tamper for example, is an essential barista tool and can significantly influence the taste of your espresso. If you're looking for the perfect espresso, aspects like pressure, level tamping, and avoiding channelling are crucial. A quality tamper can help you optimize these aspects.
1. Pressure when tamping: Correct tamping, meaning compressing the coffee grounds in the portafilter, needs one thing above all: repeatability. With no pressure at all, the puck stays loose, the water flows through too quickly, and the espresso ends up under-extracted with dominant acidity. Above a certain minimum pressure, though, the exact force plays a smaller role than was long assumed – what matters is that you tamp with the same pressure every time. A precision tamper like the Normcore delivers exactly this reproducibility through its thoughtful design, enabling an even extraction and achieving the desired taste experience.
2. Level tamping: Another important aspect of tamping is levelness. The coffee should be evenly distributed in the portafilter to ensure an even extraction. Uneven tamping can lead to inconsistent taste results. The Normcore Tamper is designed to always make level contact with the coffee grounds, which promotes an even extraction.
3. Avoiding channelling: Channelling occurs when water flows through certain areas of the coffee grounds faster than through others. This leads to an uneven extraction and can negatively affect the taste of the espresso. By using a precise tamper like the Normcore, the coffee grounds are compressed evenly, which minimizes the risk of channelling.
A Normcore Tamper offers the precision needed for an even extraction. Whether you like the result in the end is still up to you – the tool makes the cup reproducible, not automatically better.
Read more in our Coffee Knowledge: Espresso Dial-in Without a Stopwatch · Espresso: Definition and Numbers · WDT Tool · Precision Filter Baskets from IMS
Frequently Asked Questions About Tamping
How hard do I need to tamp?
More important than the force is that the puck is level. Slightly angled tamping reliably creates channelling, no matter how hard you press. Find a pressure you can reproduce, and stick with it.
What diameter does my tamper need?
It should fit the filter basket as precisely as possible. For a 58-millimeter basket, 58.3 to 58.5 millimeters is common – the less gap at the edge, the less water finds a way around it.
What is channelling?
During extraction, water seeks the path of least resistance and flows through individual channels instead of evenly through the puck. Result: part of the coffee is over-extracted, another part under-extracted – the cup tastes bitter and sour at the same time.
Do I need a tamper with a spring mechanism?
Not necessarily. It helps you practise applying consistent pressure. If you already tamp evenly, you gain little from it.
Tamping or distributing – which comes first?
Distribute first, then tamp. A tamper can't break up clumps, it just presses them together. That's what a distribution tool or a WDT tool is for.
Does tamping pressure affect extraction time?
Less than often claimed. Grind size has the bigger influence. If your extraction time varies, look for the cause in grind size and distribution first, not in tamping pressure.
Yalcin Akpinar
Co-founder, equipment and sensory
Graduate food chemist from the University of Hamburg, over 15 years in the international flavour industry, patents in flavour technology. With us he is responsible for roast profiles, bean selection and the choice of machines and grinders.
