what is espresso?
Espresso originated from the coffee culture of Italy. It is a coffee that is widely loved by Italians. In Italian, espresso means "fast" and "pressure" because it is quickly extracted under the high pressure of the steam of the espresso machine. The extremely concentrated coffee essence has a total of about 30-45cc, so it is called "espresso".
Espresso is not only the base for making all kinds of fancy coffee, it can be mixed with milk and cream to produce a variety of fancy coffee, and the direct drinking flavor is unique.
What is special about espresso?
The espresso is strong and full-bodied, with a strong bitter taste at the mouth, but a variety of rich flavors will also emerge at the same time, filling the entire mouth. Taste a cup of espresso, the endless mellow fragrance continues, the bitter taste in the entire mouth disappears, a variety of subtle flavors mainly based on sweetness, extremely mellow, invigorating, after drinking, even the bottom of the cup is full Caramel sweetness.
How to make a cup of relatively standard espresso？
Under normal circumstances, a cup of espresso extraction time of 20 ~ 30 seconds is the ideal extraction time, and there will be slight differences between different machines and grinding degrees.
Coffee grind is important
a. The grinding degree is too coarse; it will cause the flow rate of coffee extraction to be too fast, and it may extract more than 45 ml of coffee liquid in 20 seconds; the concentrated color is light yellow, the texture is thin, the fat is scarce and the maintenance time is very short; Single taste, strong coffee bitterness.
b. Too fine grinding; Coffee extraction flow rate is very slow, more than 30 seconds of extraction time, you can extract the desired milliliters of coffee liquid; but the color is dark brown, thick; bitter taste, strong irritation. (Normal extraction, concentrated liquid will flow out after 3-5 seconds)
About the amount of powder
a. Too much coffee powder; the flow rate is too slow, even the handle cannot be pressed onto the brewing head. (The coffee powder is too tamped, which can also cause problems with the flow rate)
b. Too small coffee powder; the flow rate is too fast, and the powder cake after extraction is in the form of slime. The reason is that the water will be too large due to the gap between the brewing head and the powder, and the water flow will cause the powder to roll during extraction.
The ideal amount of coffee powder is as shown in the figure below. The powder hammer presses the powder to the same level as the powder bowl (even if the standard powder amount is about 15-17 grams)
About the choice of coffee powder bowl
I suggest using double powder bowls as much as possible. The extraction rate is higher than single powder bowls, and the product is more stable. There will be a delay in the extraction time of the single-cup powder bowl.
About espresso weight
Some people produce espresso coffee by observing the amount of milliliters, while others observe the gram weight. I personally prefer gram weight. Although coffee is a liquid, milliliters are taken for granted as a unit for measuring the volume of coffee liquid.
But the fat of espresso coffee is a big factor that cannot be ignored. The oil and fat of coffee beans will gradually decrease with the passage of time, and the measurement of milliliters will not be accurate enough. (The more fat, the fresher the normal coffee beans)
Espresso extraction time
Generally, the reasonable extraction time is between 20 and 30 seconds (without considering other factors leading to extraction, the extraction time may be extended).
The time to stop extraction is also an important factor in determining the final taste of a cup of espresso. When the color of the coffee liquid becomes significantly lighter, the water flow shakes, and the flow rate becomes larger, it is time to stop the extraction immediately. At this time, the extractable substances in coffee are almost completely extracted.
Excessive extraction will produce a bitter, astringent, lignin-like fiber flavor, destroying the flavor of the whole cup of espresso. So it is also very important to choose when to stop.
Recording the parameters of each adjustment (weight of coffee powder, coffee grind, extraction time, weight of coffee liquid) is very helpful for novices to form a clear extraction scheme, which can be understood and mastered as soon as possible.