The difference between Powder dispenser and Powder Press how to correctly use the extraction parameters of Italian espresso affecting the taste of American coffee

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When making espresso, we will notice that after receiving the ground coffee powder, baristas often use two tools to "tamper" the coffee powder in the powder bowl, one is a flat cylindrical cloth powder dispenser, and the other is a powder press with a handle. Many friends asked curiously what these two tools do when watching the baristas in front of the street making espresso. The front street of this article will introduce what is the cloth powder machine and what is the powder press. Let's take a brief look at the steps of making espresso.

Clean powder bowl → grind coffee powder and pick up → cloth powder → fill → buckle and extract espresso → extraction complete and clean the powder bowl. The powder distributor and the powder press are auxiliary tools used in the steps of powder distribution and packing.

What is the use of cloth powder?

The biggest purpose of cloth powder is to make the coffee powder in the powder bowl evenly distributed and the surface smooth, so that espresso can be evenly extracted. Coffee grinded into powder from the bean grinder naturally falls on the powder bowl, there will be two problems, one is that the static electricity produced by the electric mill causes the coffee powder to agglomerate, and the other is that the overall density of the coffee powder falling on the coffee powder bowl is uneven. There are usually two ways of cloth powder, one is to use fingers to distribute powder, and the other is to use cloth powder dispenser to distribute powder.

Is it better to use fingers or cloth dispensers for coffee cloth powder?

Qianjie suggests that it is more important to use a cloth powder dispenser in the process of distributing powder. First of all, the first feeling of finger cloth powder is unsanitary, and then the coffee powder layer of finger cloth powder is more difficult to reach a uniform state, which will increase the density between coffee powder and increase the channel effect. After the excessive channel effect is formed in the powder distribution process, it will not help even if the strength of the powder is uniform in the next step. The second is the finger cloth powder, which breaks up the coffee powder caked because of the static electricity produced by grinding, causing the direct density inconsistency between the coffee powder and the coffee powder, affecting the final coffee extraction.

The advantages of powder distributor

At present, the powder distributors on the market are divided into one-word paddle type, three-blade paddle type and four-blade type. Qianjie coffee uses an one-word powder distributor. The function of these three shapes of powder distributors is to achieve a uniform distribution of coffee powder in the powder bowl. In general, the height of the powder distributor can be adjusted, and its height is actually the degree of extrusion of coffee powder. Qianjie recommends using a double concentrated powder bowl, and the height of the powder distributor is adjusted to 1mm; if a single concentrated powder bowl is used, the height of the powder distributor is 2mm. Too high dispenser will evenly spread the coffee powder at the same time there is a process of extrusion, which will also affect the strength of the powder used behind the extraction is the flow of water through.

What is the effect of pressing powder?

The main purpose of pressing powder is to prevent channel effect and make coffee extraction more uniform. After laying the powder, the gap between the coffee powder particles may still be uneven, and the loose powder layer is easy to be washed away by the hot water of 9bar during extraction, forming more channel effects. The compacted powder layer can make the coffee powder more dense, reduce the gap between coffee particles as much as possible, and reduce the possibility of channel effect.

The use of powder press is, how strong should we be?

The strength of the powder also varies from person to person. When La Marzocco designed the Swift automatic filling device around 2000, they did extraction experiments with forces ranging from 2 pounds to 30 pounds (about 15kg). It is found that no matter how strong the force is, there is almost no force at the bottom of the pressed powder. Therefore, the strength of the powder has little effect on the extraction of espresso, as long as the powder is pressed tightly. During the pressure, you can also "feel" the extrusion change of the pressed powder. There is no need to press too tightly. If the pressed powder is pressed too tightly, the resistance of the pressed powder is too strong, and it takes longer for the water to penetrate the pressed powder. Finally, the extracted coffee is sticky and bitter. Without pressing the coffee powder layer, the coffee powder layer is pressed evenly, and the espresso extracted from the coffee powder layer is made into American coffee. What's the difference?

In the front street of this experiment, the coffee beans fermented in Shirley buckets were used to extract espresso. The extraction parameters are as follows: the amount of powder is 19g, the extraction time of coffee liquid is 35ml, and the extraction time is 22s, 27s, 32s. Then three different American cups are made by adding hot water to 180ml for comparison.

The American coffee made from the unpressed powder layer has a sharp flavor, a light taste and no mellow thickness.

The American coffee made by evenly pressing the powder layer is full of whisky flavor, with soft acidity and hazelnut finish.

The flavor of American coffee made from the tightly pressed powder layer is scorched and the entrance is bitter and difficult to swallow.

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