How to avoid coffee channel effect in the later stage of Italian extraction? To learn about the soul of espresso.

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Why does espresso taste sour? Talking about the extraction Standard of Italian espresso

"Espresso" originated in Italy, and "fashion, food" is regarded as Italy's three national treasures, known as the "soul of coffee" laudatory name.

For a coffee shop, it cannot be called a coffee shop if it does not sell this drink. It is also the base for making every cup of espresso. This shows the importance of "Espresso".

What is espresso?

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It is a very strong taste of coffee, generally 7 to 8 grams of roasted comprehensive coffee beans ground into a very fine coffee powder, and then through 9 atmospheric pressure and 92 ℃ of high-temperature hot water, in 15 seconds to quickly extract 30ML strong coffee liquid called "Espresso".

To see whether there is a thick layer of brown-red grease foam floating on its surface: "Crema Krima", this is often the biggest criterion for judging the success of a cup of espresso.

Espresso has a thicker texture than water-dripping coffee. Its chemical composition is complex and changeable, and many ingredients are oxidized or decomposed with temperature.

Its most important feature is the cohesion of fragrance and taste, and the general orthodox way to drink is to drink the coffee when it comes out. While enjoying the fragrant taste, caffeine intake is greatly reduced. This way of drinking coffee, which gives full play to the taste of coffee while taking into account both health and health, makes coffee experts around the world recognize that "Espresso" is worthy of the soul of coffee.

Espresso is Italian, meaning "under pressure", which explains the importance of stress in its production. In the eyes of those who really "play" with coffee, Espresso is no longer a simple "espresso". It is not only a kind of comprehensive coffee, but also a method of roasting, but also a kind of coffee brewing, a kind of cooking, and a symbol of life.

So, what are the categories of it?

Macchiato espresso Ma Qiduo

It looks like a miniature version of cappuccino, and this coffee is more feminine. Macchiato is espresso with only a layer of milk foam instead of milk, so the taste has not been diluted, but the smell of milk only stays on the lips.

This coffee is the favorite of kung fu coffee nowadays, and it is also the type that many young cafes like to use it to make other drinks, such as caramel macchiato, actually, it just increases the quantity and caramel on the previous basis, and the taste is lightened a lot, but it still uses the name.

Double espresso double espresso

This is almost a male drink, energetic and unhypocritical, but also an enhanced version of kung fu coffee for real coffee ghosts, which is a favorite of fish.

General single from 7-10 grams of powder in 25-30 seconds out of 25-30ml, double is 14-20 grams of powder out of 45-60ml. This, like the spirits in the wine circle and the essence in the perfume, can be spoiled by drinking this kind of coffee. If you get used to such a strong taste, you will be drinking water when drinking other coffee.

In addition, there are old witch people who like to add wine to the Double, such as rum or whiskey, to the satisfaction of being surrounded by taste buds.

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Con Panna espresso Herbalife

Pour thick whipped cream on the surface of espresso, it is a more retro style of kung fu coffee. Much like the aristocracy of tsarist Russia or the Austrian royal family, perhaps it was because there was less whipped cream in that era.

Coffee shops usually put whipped cream in a glass and serve it together with espresso. Cafes are filled with glasses, and in order to allow guests to enjoy the interface between whipped cream and coffee, the waiter will usually help add it, from the initial clean break, followed by a slight infiltration, and finally the clear and dark brown liquid becomes turbid, and the sweetness of the cream spreads in the bitter coffee and becomes amiable. If you want to try kung fu coffee, you can start with this one.

Single espresso espresso

It is the basic style of kung fu coffee. It is the most popular coffee in Europe. If you go to a cafe or restaurant to order coffee, the waiter will definitely bring you a cup of such coffee directly. They like to use a small glass similar to Shooter, and most of them drink it up in one or two mouthfuls, and few of them are slow, contrary to the slow chewing of Chinese Kungfu Tea.

Espresso frees people from the unfathomable production of individual coffee and complex coffee beans, usually deep-roasted coffee beans, which, once approved and confirmed, will not change for decades, and the taste is stable.

Coffee extraction is very knowledgeable, especially in the production of this piece by Espresso.

So what are the terms involved in extraction?

Terminology of coffee extraction

Blonding: the process of changing the liquid from a dark brown with tiger stripes to a uniform light yellow. This situation often occurs in the last 1amp 3 stage, which also indicates that the extraction operation can be ended. The excessive yellowing part of espresso has a light taste and almost no aroma. If it lasts too long, it will dilute the mellowness and reduce the taste.

Channel effect (channeling): water flows rapidly through cracks in coffee cakes, resulting in thin, underextracted espresso. At this point, you will usually see a yellowing stripe suddenly appear in the coffee stream, which will leave a pencil lead-sized hole in the coffee cake.

Coffee oil (Crema): make sure that espresso makes the appropriate signal that various gases-air and carbon dioxide-are distributed in water under high pressure. The liquid also includes emulsified oil. A deep golden brown foam is formed on the surface of espresso.

Gold (extraction) rate (Golden rule): it is often used to describe the ideal time and capacity for extracting espresso. The Italian National Coffee Institute (Instituto Nationale Espresso Italiano) provides a practical definition of the ideal espresso properties, although these parameters are more like the "golden rule" than mandatory rules. The simple definition is: use about 16-18 grams of coffee to produce 60 milliliters of double espresso in 22-27 seconds (from the time the coffee liquid flows out).

Over-extraction: too much coffee solids are extracted to produce a strong, irritating aroma. Visually, the capacity of coffee is insufficient, and coffee oil is a thin layer of blackening. The dark black circle on the edge of the cup is another important hint of excessive extraction or excessive extraction of water temperature.

Pre-wetting (Pre-infusion, also known as pre-soaking): the coffee powder is infiltrated into the espresso machine before it is actually extracted. Some coffee machines are achieved by pumps, which work for 1-2 seconds, stop for 1-2 seconds, and then start to continue to extract coffee. Full automata and some automatic machines use this method. The other is "natural" or progressive prepreg, which is the kind of machine equipped with E61 outlet head. After the pump starts, the pressure is completely applied in front of the coffee cake, and the second cavity must be filled. It provides 3-7 seconds of soaking time for coffee powder before the pressure is established, and it is also a popular extraction method.

Tiger spot stripes and variegated spots: the main visual cues for good extraction. The tiger spot is formed by the contrast between dark and light coffee oil in the coffee stream and ideally appears at the beginning of the coffee and lasts until the end. "mottling" is the performance of good extraction in the cup; refers to the dark brown spots and reddish brown markings formed on the surface of coffee oil.

Insufficient extraction: coffee solids are not extracted enough to produce a light, boring aroma. Visually, it is a fast and large-capacity extraction, and the coffee oil is a uniform light yellow.

How to extract it?

So how can we better extract a cup of espresso?

In order to make everyone understand better, Yuyu specially made a group of simple pictures.

Please find the corresponding picture according to the text, look at it one by one, and you will understand.

1. Remove the brewing handle from the coffee maker. (you need to pay attention to two things: keep your hand on the brewing head to keep warm, and don't put it on a warm cup or plate or anywhere else, otherwise the low temperature handle when brewing coffee will lower the temperature of the brewing water and cause the coffee to turn sour; the coffee grounds inside should not be deducted before brewing the next cup of coffee, because the copper brewing head at high temperature will produce a peculiar smell, and the coffee grounds can absorb the smell. )

two。 Deduct the coffee grounds. Handles that have not been used for a long time will cause coffee grounds to stick to the bottom of the coffee filter and can be brushed off with a plastic brush. )

3. Buckle the hand to the brewing head, press the brewing key to wash the handle and the brewing head, and shake the handle constantly in order to rinse the coffee residue glued to the brewing head. (note: if you load the powder directly without rinsing the head, the residue glued to the head will be extracted again, causing the coffee to become bitter and astringent. In addition, this is also equivalent to releasing water in the front section to prevent the temperature of the cooking water from being too high, resulting in excessive extraction.

4. The coffee residue in the hand will be poured out. (the action of flushing the head can be repeated to ensure that the head will be washed clean. )

5. Wipe the filter in your hand completely with a dry towel. (it is absolutely necessary to ensure that the filter is dry. If there is water in the filter, the coffee powder will start the coffee extraction process before brewing, resulting in excessive extraction. In addition, it will also make the coffee powder agglomerate, resulting in uneven filling pressure. And the outlet of the handle should also be dried by the way to prevent the coffee powder from flowing into the cup. )

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6. The dried filter can be powdered now. (it should be noted that there is no powder left in the dispenser. Each time it is boiled and ground, the coffee powder will oxidize completely after being exposed to the air for a few minutes, and the brewed coffee will not be able to drink. Now some coffee shops are used to filling up their dispensers, which is not correct. The right thing to do is to quickly pull the dispenser lever while grinding the powder, turn it off when the handle is almost full, and continue to pull the dispenser lever until all the coffee powder in the dispenser falls into the brewing handle. )

7. A powdered handle. The powder in the handle should be piled into a hill so that the inside of the handle will be completely filled when powdered. )

8. Smooth the powder in the handle with your hand or scraper. (two precautions: wipe the coffee powder back and forth when applying the powder, make sure that the coffee powder fills all the gaps in the handle, and wash your hands first if you wipe it with your hands; put the excess powder into the dregs bucket, not back to the counter, otherwise the coffee powder burned by the high temperature handle will affect the taste of the next cup of coffee. )

9. The handle after powdering is finished, pressing powder for the first time. The force of the first filling should not be too great, just press the coffee powder into the filter, generally within the 5kg. )

10. Tap the handle once laterally to make the coffee powder on the edge of the filter fall into the filter. (note: do not overpower, generally also in the 5kg, otherwise it is easy to concentrate coffee powder on the other side of the filter. In addition, you can only knock once. Fish have seen many people do multiple knocks, which is incorrect, because repeated tapping on the outside of the handle will concentrate the coffee powder to the middle of the filter, creating an edge gap and making the coffee extraction unbalanced. )

11. Secondary pressing powder. (note: the pressing force should be controlled within 10-20kg, and the strength mainly depends on the grinding thickness of the coffee powder; keep the forearm vertical, otherwise the coffee powder will be high on one side and low on the other in the filter, resulting in extraction imbalance. This is difficult and requires a lot of practice. some people have to practice thousands of times to make sure that most of the packing is flat. )

twelve。 After the powder pressing is completed, rotate the powder press more than 360 degrees, the purpose is to make the coffee powder surface smooth, better resistance to cooking water pressure to ensure normal extraction.

13. Buckle the hand to the head. (note: press the brewing button immediately after buckling, and then get the coffee cup. In addition, the whole powder filling process should be rapid, because the coffee powder in the high temperature handle for too long will burn the coffee, causing the coffee to become bitter. )

14. Coffee extract. The normal extraction time is 18 to 25 seconds to extract 20 to 30ml coffee, this is a personal point of view.

15. After the completion of the Espresso (after the completion of the coffee handle, coffee pressed powder surface smooth should not have any depression, otherwise the filling pressure is not correct, need to continue to practice. )

WBC (World Barista Championship)

The following basic settings are made for Espresso:

1. Capacity. The amount of coffee is lounce (including crema, between 25--35ml)

two。 The water is warm. Water extraction for 90.5 MULTHUE 96 degrees.

3. Air pressure. 9.5 atmospheres for 8.5 Murray.

4. Time, 30 seconds in 20muri.

5, jet lag. The Espresso extraction time difference of each coffee is less than 3 seconds.

6, coffee cup. Espresso must be crashed into 60--90ml 's container with a special coffee cup with a cup ear. The special coffee cup has a unique name demitassecup.

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