Coffee extraction Cognition: how to avoid Coffee Channel effect

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When we are ready to make Italian concentration, we should first make the coffee powder in the handle powder bowl flat, so that the coffee powder on the surface of pressed powder is evenly distributed, so that the water for brewing coffee can effectively extract the rich oil, as well as the delicious flavor from the place of origin that has been carefully baked by the baker. However, in the preparation steps before extraction, any errors in any link will cause channel effect.

The pressure of extraction concentration is 9Bar, which is four times the tire pressure of the car. Under strong work pressure, water will also be lazy, water will find the easiest "emergency passage" from Coffee pressed powder, and then smoothly through pressed powder. Perfect to avoid the coffee oil that should have been precipitated, after the channel effect, extract a cup of water, mild espresso.

Then how can this be avoided?

Use the correct amount of powder

In a 22-gram powder bowl, only 18 grams of coffee powder is more likely to have a channel effect. There are two main reasons for the channel effect-the top space (that is, the space between the surface of the coffee pressed powder and the brewing head) and the particle size of the coffee powder. If you use a small amount of coffee powder, you should grind the coffee powder finer accordingly, which will not only cause the coffee powder to agglomerate, but also increase the channel probability. Therefore, try to use the amount of coffee powder appropriate to the size of the powder bowl, which can help avoid extracting a cup of light espresso.

The powder pressing force is correct.

The correct pressing powder should be uniform. Because water is "lazy", if your pressed powder is on the wrong side, the water will flow from the high to the low, and then find the easiest place to pass, leaving all the most delicious substances in the pressed powder.

When receiving the powder, the coffee powder sometimes overflows the powder bowl. in order to hold the same amount of coffee powder, we may choose to knock the powder bowl against the bean grinder. But with regard to this step: first, please knock lightly; second, one or two knocks are enough. Otherwise, the bottom of the pressed powder will be too stocky, and the pressure exerted by the top powder hammer will make the density of the top and bottom of the coffee pressed powder uneven, easy to extract unevenly and produce channel effect.

And in the past, people adopted the habit of knocking on the edge of the bowl after pressing pressed powder, in order to knock off the coffee powder glued to the wall of the bowl, making the inside of the bowl look cleaner and extract evenly. But this method will create cracks in the originally compacted pressed powder, making it easier to form a channel.

So you can choose to tap the powder first, shake it from left to right, and then distribute the top coffee powder evenly with your fingers. In this step, if it is difficult to be consistent after practicing for a period of time, it is recommended to use powder dispensers, powder dispensers and other related instruments to assist.

Use the correct powder hammer

If the 56mm powder hammer is used to tamp the 58mm powder bowl, there will be a lot of coffee powder that has not been tamped. If you use a VST powder bowl, you need to use a larger powder hammer, which is about the same as 58.4mm, so that the powder hammer and powder size better match. Also, the action of pressing powder is to press the powder hammer down vertically and lift it vertically.