This post was updated on: December 7, 2019
Tamping is the art of compressing the coffee grounds in the portafilter which results in perfectly brewed espresso out of the espresso machine. Moreover, the premium espresso machines will have built-in tamper with the calibrated pressure value for perfection. On the other hand, many Baristas prefer tamping the coffee using the espresso hand tamper for definite results. Therefore, let’s understand the reasons for tamping the espresso using the machine tamper or hand tamper for the better taste.
Brewing an Espresso
The prerequisite of brewing espresso is tamping the coffee grounds using a tamper. Thereafter, you can have the espresso when the hot pressurized water passes through the coffee puck. It is the age-old process of making espresso and so is the tamping the coffee grounds.
So, without further ado, you can go through the reasons proving the importance of tamping the espresso below.
1. Providing a Gap Between Coffee Bed and Water Dispenser
The espresso machine delivers hot pressurized water through the outlet i.e. the junction between the portafilter and the machine. At that point, you don’t want to have the coffee grounds near the water outlet tip, it will save the tip from clogging by the coffee sludge itself.
Having said that, the coffee grounds will compress substantially after tamping with the appropriate pressure. In the same manner, the coffee bed that forms after tamping will create an essential gap between the water outlet point and the coffee puck.
2. Uniformly Distributing the Coffee Grounds
Tamping does not only aim at compressing the coffee grounds but also distributing the coffee evenly in the portafilter. However, the brewer has to disperse the coffee before tamping the grounds but still, the credits for distributing the coffee belong to the tamping process.
Brewing the espresso shot deals with two major intricacies i.e. under-extraction, over-extraction due to under tamping, and over tamping respectively. We are talking about the coffee pucks which are evenly distributed and still can end up as a fault brew. Whereas, we will talk about the unevenly distributed later in this sub-section.
Moreover, tamping either too loose or too hard is never an option but only the optimum tamping pressure so that the grounds form a bed with uniform density and cross-sectional area.
3. Allowing Water to Pass Through Coffee Bed Evenly
The coffee puck with uniform cross-sectional area and density will not allow the water to stream down partially extracting the coffee puck. Instead, the coffee bed will even channel the pressurized water through evenly and extracting the grounds perfectly.
Further, the fluidity of the water will exploit any cracks, voids, uneven density if you do not tamp the grounds properly. In fact, you need to maintain the vertical alignment of the tamper while tamping. Because it can result in forming the titled surface of the coffee and uneven cross-sectional area.
4. Tightly Packed Puck Forces Water to Drain Slowly
The pressurized hot water passing through the coffee requires a few seconds to brew the grounds perfectly. In fact, many espresso machines feature the pre-infusion method to perfectly brew the grounds. Pre-infusion is the method of introducing hot water with low pressure to the coffee puck for preparing the grounds for actual pressurized hot water. And, hence pre-infusion helps the grounds to blend perfectly in the water i.e. extract in the water.
In the same manner, the appropriate tamping the ground will result in clogging the water and extracting the grounds completely. Hence, again, tamping the coffee grounds is important to allow water clogging to an appropriate extent.
5. Coffee Infusing with Water
The pressurized hot water slowly passing through the coffee will extract the coffee! This is the main principle of any espresso machine. Having said that, the coffee puck will blend completely in the water only if the puck is tamped with optimum pressure.
You neither have to bother knowing the accurate pressure required for tamping coffee nor does any such specific pressure value exists.
However, tamping is the key factor which leads the extraction in a perfect manner. It is the reason for the water forcing out itself by extracting the grounds. Because, otherwise, the coffee can develop the bitter or sour taste due to improper extraction.
Here were the five important reasons proving the importance of tamping the coffee grounds to make espresso. In fact, we saw the difference between tamping too loose and too hard leading to improper coffee extraction. Not to mention, there are five major reasons supporting the tamping process prior to brewing espresso.
However, can you tell us a reason which proves the importance of tamping before brewing the espresso shot?