Does handle temperature have any effect on espresso extraction? Should I preheat the head of the coffee machine

Recently, Qianjie saw such a puzzle: "is the extraction of espresso stronger when the head is cold than when it is hot?"

Qianjie guessed that the implication of this friend was whether the handle would affect the extraction of espresso at different temperatures and whether to adjust the strength of the powder. In that case, we might as well do a round of experiments.

In this experiment, the front street is compared by changing the temperature of the handle, fixing the amount of powder and liquid weight, and recording time variables, and other controllable parameters are kept consistent as far as possible. During the experiment, the extraction time, the concentration and flavor of espresso, and the taste characteristics of the same amount of hot milk were recorded.

Galileo grinding machine grinding scale: 2.0handle: bottomless coffee machine extraction temperature: 94 ℃ Coffee powder content: 20g concentrate weight: 38g

The handle temperature is divided into three types: high temperature handle, room temperature handle and low temperature handle. (the low-temperature handle will be put into the refrigerator freezer for 1 hour in advance and then used; the high-temperature handle is fastened to the coffee machine to let it heat up until it becomes hot.)

In the experiment, sunflowers from Qianjie store were used to mix coffee beans. The ideal extracted flavor is vanilla, hazelnut, caramel, fermentation, and sweet and sour berries. Hot cream coffee is the flavor of vanilla, cream and wine heart chocolate. The experimental data and results are as follows

Refrigerated handle: extraction time is 30 seconds, the concentration is 10.52%.

Concentrated: vanilla, berries, cream, outstanding acidity, low alcohol thickness

Milk coffee: berries, chocolate, heavy milk, thin taste

Preheating handle: extraction time 29 seconds, concentration 10.22% concentrated: wine, hazelnut, caramel, tropical fruit sour and sweet, obvious sweetness, alcohol thickness full milk coffee: chocolate, nuts, cream, fermentation aroma, rich room temperature handle: extraction time 27 seconds, measured concentration is 9.96% concentrated: chocolate, sour, bitter slightly heavier, alcohol thickness low milk coffee: hot cocoa, soft taste, slightly astringent aftertaste after cooling

I believe you can notice from the experiment that the difference in handle temperature will affect the extraction of espresso, and there are differences in flavor performance, but cold storage and preheating do not cause much difference in concentration and extraction rate.

By tasting the concentrated coffee and milk coffee, it is found that the preheating of the handle is beneficial to the extraction of mellow substances in the coffee, the overall taste is more solid, while the cold storage highlights the soft fruit aroma and the acidity is brighter. For example, the warm sun blend in the former street, the preheating handle gives Espresso a richer aroma and fruit flavor, and the milk coffee is more mellow, which meets our extraction requirements for this bean.

Of course, there are other factors that may change in this experiment, such as the strength of pressing powder, the change of the state of coffee beans and so on, and the roasting degree of coffee beans will also affect the effect of temperature change. But Qianjie should emphasize that the purpose of this experiment is not to find a way to make Espresso taste better, but to verify whether the handle temperature has any effect on the extraction. The conclusion is: it has an impact!

Back to the friend's question at the beginning, "is it harder to press the powder when the head is cold than when it is hot?" In the experiment, Qianjie tried to keep the powder strength of the three tests the same, and the extraction of espresso changed accordingly with different temperature, so the powder strength did not need to be adjusted. I just felt that pressed powder was filled and compacted.

As for whether the handle should be preheated in advance or placed at room temperature, Qianjie believes that it should be based on the roasting degree of the coffee beans we use (whether the flavor is sour or bitter), combined with the taste performance of concentrated, American or milk coffee. and then analyze which extraction method (details) is better. After all, the ultimate goal is to make the coffee taste better, right?

-END-