Whether the handle of espresso should be buckled back to make the head or the effect of room temperature on the flavor of coffee

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Guide reading

"after the espresso is extracted, should the handle be fastened to the brewing head to keep warm or should it be placed at room temperature?" Baristas have different views on this issue. Some baristas think that the handle buckle in the brewing head can keep the whole handle (including powder bowl) at the same temperature, reducing the effect of temperature difference on the flavor of coffee; others think that buckle in the brewing head can easily lead to high temperature of the handle as a whole. High temperature will affect the flavor of coffee.

Contrast experiment

Qianjie is extracted with three different temperature handles this time to see what effect the handle temperature has on the flavor of espresso.

The Italian coffee beans used in the front street of this experiment are sunflower sunflower coffee beans, which are made of Shirley coffee beans and Yejabee red cherry coffee beans at 7:3. The extraction parameters are as follows: Pegasus E78 espresso machine, Pegasus 900N bean grinder, grinding degree 1.9, double handle, coffee powder 20g, extraction coffee 35g (double espresso P, extraction time 25 seconds).

Group An experiment

The whole handle (including powder bowl) was extracted at 26 ℃. After extraction, the temperature of espresso was 63.2 ℃.

The flavor of espresso in group An is as follows: whisky, milk chocolate, vanilla cream, soft sour aroma, caramel-like finish, obvious aroma and rich taste.

Group B experiment

The handle buckle at room temperature is preheated by putting water in the boiling head for 5 seconds, and the overall temperature of the handle is 56 ℃. After a series of operations, such as filling powder, cloth powder, pressing powder and so on, the overall temperature of the handle is reduced to 50 ℃, and the temperature of espresso after extraction is 64.1 ℃.

The espresso flavor of group B is as follows: wine heart chocolate, vanilla, caramel aftertaste, acidity and aroma are not as obvious as group A, but nutty flavor is prominent.

Group C experiment

After the handle buckle at room temperature for 15 minutes, the overall temperature of the handle reaches 74 ℃. After a series of operations, such as filling powder, cloth powder, pressing powder and so on, the overall temperature of the handle is reduced to 69 ℃, and the temperature of espresso after extraction is 64.8℃.

The espresso flavor extracted in this group is as follows: dark chocolate, nuts, smoky, fruity and sour, slightly scorched and insufficient aroma.

Experimental results

Through the comparison of three groups of experiments, we can see that the flavor of espresso extracted by room temperature handle is the most balanced; the nutty flavor of espresso extracted by preheating handle is more prominent, but the aroma is slightly insufficient; the espresso extracted by high temperature handle has insufficient aroma, smoky and scorched smell. At the same time, we can notice that no matter what the temperature of the handle is, there is little difference in the temperature of espresso extracted by the three groups of experiments. Qianjie believes that it is the temperature of the powder bowl that affects the flavor of the coffee rather than the temperature of the handle.

After preheating in group B, the temperature of the coffee powder bowl will be in a semi-high temperature state. When the coffee powder falls into the powder bowl, the temperature will accelerate the volatilization rate of light molecular weight flavor substances (such as acid, flower fragrance). When the sour flavor weakens, the medium molecular weight flavor substances will be more prominent (such as nuts, chocolate). This explains why the sour flavor of group B is less prominent than that of group A, but it is more able to reflect the nutty flavor.

Group C is the same as group B, because the powder bowl is in a state of high temperature, both light molecular weight and medium molecular weight flavor substances are accelerated to volatilize, and heavy molecular weight flavor substances will appear (such as smoking, bitterness).

In front of the street, it is not recommended that the handle be buckled in the head for a long time to keep warm. When extracting coffee, you can choose the handle or handle at room temperature to preheat quickly according to the flavor you want to express.

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