Tamping coffee ensures that the ground coffee is evenly ground, compacted, and smooth, allowing for even extraction in an espresso machine. This technique can completely change the final result of the beverage.
Doing it like a pro isn't as easy as it seems, but here are some tips that can help you achieve it.
Why tamp coffee?
This method is used by baristas to take a quantity of ground coffee and turn it into a tightly compressed, uniform disc inside the portafilter, where the water and coffee will come into contact during brewing.
Why is it necessary? For one thing, the coffee needs to be tamped enough to create a small space between the top of the coffee and the screen through which the water exits the espresso machine. Once the coffee gets wet, it will naturally swell slightly, which can cause an unfortunate overflow.
How to Tamping?
- Level the ground coffee
Pour the measured coffee into the portafilter; then take your index finger and run it along the top of the portafilter, removing any excess. It should be even and level.
- Place the tamper on a level surface
If possible, place the portafilter on a flat surface so that it is level.
Keep your wrist straight and your elbow bent at approximately a 90-degree angle. This helps the energy flow from your body rather than your wrists (this technique prevents injury and allows you to control the pressure).
- Apply light pressure
Apply a light amount of pressure to form a puck with the ground coffee. The goal is to achieve a flat surface. An uneven surface will result in poorly extracted espresso.
- Apply more pressure
Now that you have a level surface of ground coffee, it's time to press a little harder.
Once you have formed a disc, apply more force and push down harder to eliminate any gaps between the edges.
- Give it a twist
As you apply final pressure, you can rotate the tamper to leave a smooth, compacted finish.
- Clean loose coffee
Before finishing, take a cloth and wipe away any excess ground coffee that may have spilled around the edges of the portafilter. The portafilter should fit easily into the machine without obstruction.
The right tools
- Coffee distributor
It facilitates proper leveling of the grinding surface. Its diameter should match that of the portafilter.
- Tamper mat or coffee tamper pad
It helps to properly support the portafilter on the countertop (or tabletop), to prevent it from slipping when applying pressure to it.
- Calibrated pressure tamper
Indicates the optimal pressure to be applied for proper tamping.
4 types of tamper
There is some debate about whether rounded (convex) or flat-bottomed tampers are better. However, in general, tampers come in four basic styles.
- Dual-head tamper: This tool looks like tilted dumbbells with two flat ends, one slightly smaller than the other. It's useful if you have multiple baskets and is ideal for the home barista.
- Tamper: These tampers resemble an old-fashioned rubber stamp with a flat or convex bottom and a round knob handle. Knob materials range from metal to wood. These allow you to add more force and are preferred by professional baristas.
- Weight-calibrated tamper: This is an option often included with handle tampers. Force feedback is standard, although other weights are available.
- Puck Tamper : Some baristas prefer the style of tamper that resembles a hockey puck. These are flat and held as if you were holding a ball.
The art and science of tamping may seem complicated and overly technical at first, but once you understand it, it will become easier. It's worth taking the time to learn how to prepare it properly and achieve the perfect espresso.