How Tightly Should Coffee Grounds Be Tamped When Making Coffee-What Happens if Coffee Grounds Are Tamped Too Tightly

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The Importance of Tamping in Espresso Making

When making a good espresso, FrontStreet Coffee believes that the most fundamental yet crucial step is tamping. If the flow rate is too fast, the tamping pressure is too light; if the flow rate is too slow, the tamping pressure is too heavy. These factors directly affect the quality of the final espresso and its taste. When making espresso, you'll notice various tools like portafilters, distribution tools, and tampers. Some people ask FrontStreet Coffee: "既然 you already have a tamper, why do you need a distribution tool? Is a distribution tool absolutely necessary?" And "How much pressure should be applied when tamping?" Today, FrontStreet Coffee will take you through an in-depth understanding of these questions.

When extracting espresso, sometimes using the same parameters to produce multiple cups of espresso can result in inconsistent extraction. After ruling out machine issues, it might be caused by inconsistent tamping. FrontStreet Coffee considers the tamper an essential tool when extracting espresso. The purpose of tamping is to achieve more even coffee extraction and maintain consistent output while reducing error rates.

The Purpose of Tamping

1. Prevent channeling effect and make coffee extraction more even.

After distributing the coffee grounds, gaps between coffee particles may still be uneven. Additionally, loose coffee powder layers can be easily scattered by 9-bar hot water during extraction, forming channeling effects. Compacting the coffee powder makes the coffee grounds denser, minimizing gaps between coffee particles and reducing the likelihood of channeling.

2. Ensure output stability and reduce error rates.

Extracting espresso is a technical process. Every time you dose and distribute coffee, we cannot ensure consistency in the gaps between coffee particles. As the final step before extraction, tamping plays a crucial role in determining whether espresso extraction will be stable.

Experiment: Tamping vs. No Tamping

Let's try extracting espresso with and without tamping to see the differences. For this experiment, we'll use FrontStreet Coffee's own "Frontsteet Sunflower Warm Sun Blend." FrontStreet Coffee's Sunflower Warm Sun Blend combines Frontsteet's Sherry Barrel Processed Coffee Beans and Frontsteet's Natural Process Yirgacheffe Red Cherry Project, in a 6:4 ratio. Sixty percent Honduras Sherry Barrel coffee beans provide flavor and body to this blend, while forty percent natural process Yirgacheffe contributes more aroma and acidity. Coffee bean information is as follows:

FrontStreet Coffee · Frontsteet Sunflower Warm Sun Blend

Blend composition: Frontsteet Honduras Sherry Barrel & Frontsteet Yirgacheffe Natural Red Cherry

Composition ratio: 6:4

Flavor description: Vanilla, cream, fermented wine aroma, chocolate

FrontStreet Coffee used 20g of coffee grounds to extract 40g of Espresso. Experimental results are as follows:

Distribution Tool Distribution Without Tamping

Coffee liquid volume: 40g

Extraction time: 22s

Observation of extraction process: Spraying during liquid output, unstable flow rate throughout.

Sensory experience: Sharp acidity, watery texture

With Tamping

Coffee liquid volume: 40g

Extraction time: 27s

Observation of extraction process: Overall uniform flow rate, no spraying phenomenon.

Sensory experience: Rich chocolate and fermented wine aroma

Distribution Tool

FrontStreet Coffee believes that distribution is an important step in making a qualified espresso. The quality of distribution can even affect the success or failure of a good coffee, and it's also an important assessment and scoring item for many baristas.

The two most important purposes of distribution are breaking up clumps and leveling.

1. Breaking up clumps

Allow particles of different sizes from the grinder to be distributed as evenly as possible, avoiding concentration of coarse or fine particles, and preventing clumping;

2. Leveling

Spread the coffee evenly in the portafilter basket, ensuring even distribution throughout, without areas of excess or shortage, no mounds or empty spaces.

Common distribution methods include finger distribution and tool distribution. Finger distribution involves gently moving fingers back and forth across the portafilter basket to level the coffee. Note that this should be done horizontally along the basket edge, not pressing down on the coffee layer.

Distribution tools can achieve effects like mixing coffee grounds, breaking up clumps, and evenly distributing particles. However, they also have drawbacks: wasting coffee grounds, complex tools requiring certain skills to operate, downward pressure during distribution that may cause internal cracks, only smoothing the surface without guaranteeing consistent distribution and thickness.

Tamper

Tamping is the process of compacting loose coffee grounds with a tamper so that the coffee puck can provide some resistance when facing 9-bar water pressure.

1. Prevent channeling effect and make coffee extraction more even.

After distributing the coffee grounds, gaps between coffee particles may still be uneven. Additionally, loose coffee powder layers can be easily scattered by 9-bar hot water during extraction, forming channeling effects. Compacting the coffee powder makes the coffee grounds denser, minimizing gaps between coffee particles and reducing the likelihood of channeling.

2. Ensure output stability and reduce error rates.

Extracting espresso is a technical process. Every time you dose and distribute coffee, we cannot ensure consistency in the gaps between coffee particles. As the final step before extraction, tamping plays a crucial role in determining whether espresso extraction will be stable.

Differences Between Distribution Tool and Tamper

After reading FrontStreet Coffee's introduction above, do you understand the difference between the two? FrontStreet Coffee will summarize briefly: a distribution tool only makes the coffee grounds even, while a tamper compacts loose coffee grounds so that the coffee puck can provide some resistance when facing 9-bar water pressure.

Is a Distribution Tool Necessary?

FrontStreet Coffee believes that if your grinder's output quality is decent and not too clumpy, you can simply level the coffee. Simple hand smoothing or tapping can basically achieve even distribution. Combined with appropriate tamper techniques, you can achieve consistent output. If you're producing in large quantities or have higher quality requirements, you can choose suitable tools to assist as mentioned above.

How to Tamp Correctly

FrontStreet Coffee believes that first, you should choose a tamper that matches your portafilter's diameter. Mismatched diameters might result in inability to tamp properly or gaps between the tamper and the portafilter edge, making tamping ineffective.

Tamping posture varies from person to person, but the general principle is that the tamper handle should be perpendicular to the portafilter basket, and the force applied to the tamper should be evenly distributed. Press down on the portafilter to make the coffee layer smooth and even. If uneven force causes the tamp to be slanted, the high-temperature, high-pressure water from the group head will seek the path of least resistance, causing uneven extraction.

The tamping pressure also varies from person to person. Around 2000, when La Marzocco was designing their Swift automatic filling device, they conducted extraction experiments with forces ranging from 2 pounds to 30 pounds (approximately 15kg). They found that regardless of the force applied, almost no force reached the bottom of the coffee puck. Therefore, the magnitude of tamping pressure doesn't significantly affect espresso extraction as long as the coffee is compacted. During tamping, you can also "feel" the compression changes in the coffee puck. There's no need to press too tightly. If the puck is compressed too tightly, its resistance becomes too strong, and water takes longer to penetrate the puck, resulting in coffee that is thick and bitter.

After tamping, small clumps of fine coffee may stick to the tamper or portafilter surface. At this point, simply rotate the tamper gently before removing it.

For more specialty coffee beans, please add FrontStreet Coffee on private WeChat, ID: kaixinguoguo0925

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473