QARR - Coffee Tamper Guide

Tamper your way to quality espresso

Relevant to manual, semi-automatic and automatic espresso machines, a tamper is used to evenly distribute and pack the coffee grounds in
the filter basket such that brewing water pounds through the coffee cake evenly, soothing out every drop of flavor from the ground coffee.
Water is lazy. Given a choice, it will take the path of least resistance, resulting in an uneven extraction of flavor or weaker cup. With the strong
pressure under the electric pump, a softly packed coffee cake will be blasted into many pits, allowing water to flow through easily, short of
extraction. Therefore, it is necessary to give a hard tamp of around 30 pounds (or around 13 kg) in order to maintain a consistent density
across the leveled coffee cake, for the brewing water to ooze through at the right rate to achieve the ideal extraction. Another advantage of a
hard pack/tamp is to allow for a coarser grind size that minimizes the chance for heat damage and oxidation between the time the coffee
beans are grinded and the time the final cup is made.

Having a great espresso machine by no means is the answer to a great cup. What is also important is to have a good tamper that can assist
in giving the right tamp. So what is considered as a good tamper? Before we delve into the anatomy of the good tamper, it should be
highlighted that the tamping base built into coffee grinder by no means does not provide a good tamp because 1) it is not ergonomically fitted
to give an evenly distributed and flat tamp, and 2) the one-size base may not necessarily provide a full tamp, depending on the porta-filter
basket size.

A tamper is made up of 2 parts: handle and base. The best handle is one that provides the best grip, thus the size, shape and material are
important determinants of a good handle. In terms of size and shape, the best way to choose is to try it. Next comes the material. The 4
most commonly used materials in tampers are stainless steel, aluminum, plastic and wood. To ensure a good grip for a hard tamp and
good control for leveling the tamp, wood and plastic are better choice as compared to stainless steel and aluminum because the latter
materials can slip relatively easily. Furthermore, with a natural touch, wood handle usually comes in stylish carve that adds an esthetic look
to the tamper. Due to its good look, it has become collector’s item, or even a decorative piece of art. Given its light weight, when paired with a
much heavier base, such tamper provides an excellent control over the tamping process.

On the other hand, the latter materials provide much heavier weight, especially in the case of stainless steel that is also the most lasting of
all the materials mentioned due to its hardness. With its heavy weight, it lends itself to the 30 pounds necessary for a good tamp.

As for the base, 3 factors are considered: material, base surface and size of base. In terms of material for the base, stainless steel again
scores highest in this category attributed to its weight and hardness that provide a rock solid and stable base which aid in the tamp. The
hardness of stainless steel also helps to dislodge coffee grounds that stick to the wall of the filter basket by striking it lightly against the
portafilter after the initial lighter packing (meant to level off the grounds, and in certain cases provide a tamp to the lower level of grounds),
before the final hard pack. Aluminum is also a good candidate for the base except that it is a softer metal that over time may lose its shape,
accelerated with dropping and striking against the portafilter.

Conventional wisdom agrees that flat base surface ensures level coffee grounds and even compactness across the packed coffee cake.
There is no question about it. Then comes the convex surface base which promises uniform tamp because any slight slippage is
compensated by the curve surface left behind. Another benefit of convex surface is that the curved base distribute part of the tamping force
towards the side wall of the filter basket, further sealing the sides to prevent water from taking the path of least resistance. Some espresso
machines’ shower screen is curved with a screw in the center, so a curve base matches well in terms of the distribution of force. Even
celebrity espresso preparation specialist, author of “Espresso Coffee: Professional Techniques” and “Techniques of the Barista”, and
founder of Espresso Vivace, David C. Schomer, is an advocate of convex tamper and has designed the Ergo-Packer tamper with a convex
surface. Nonetheless, it is not proven as to which surface (flat or convex) provides the best distribution of coffee grounds with equal
density/compactness in the filter basket, so it is still a matter of personal preference.

Since the objective of tamping is to apply even distribution and pressure of coffee grounds both horizontally and vertically, the surface area
where the force is applied should match exactly to the circular area of the filter basket. That is why the size of the tamper base becomes
important. As most of the notable brands of espresso machines stick to the standard size of 58mm, there are also other brands that prefer to
use a different size. Below is a table of some of the most common brands of espresso machines and their corresponding tamper size.

58 mm	Other sizes
Astoria	Astra – 56mm
Brasilia	Bodum Granos – 51mm
Bunn	Francis!Francis! X1 – 56mm
Caramali	Krups – 49m
Cimbali	Spaziale S1 – 53mm
ECM
Elektra
Expobar
Faema
Fiorenzato
Gaggia
Grimac
Isomac
Nuova Simonelli
La Valentina
Pasquini Livia
Rancilio
Wega

Tamping is still a very much a manual process, and if you are used to a particular tamper, stick with it. Just like a computer notebook is to an
IT professional, or a paint brush is to a painter, a tamper is a tool that is very personal. Not only is it functional, it also reflects on the owner.
So why not choose a well-built, good looking tamper that not only helps you to make the perfect cup, but also sits proudly on top of your
beloved espresso machine.

The verdict: Choose a tamper with either a wood, stainless steel or aluminum handle, paired with a strong and hard stainless steel base.
Flat or curved base is a matter of choice and preference.