Several points that should be paid attention to in making espresso Espresso

[1] bean

Requirement: there is no good espresso without good coffee beans. Coffee beans must be fresh. Take espresso, for example, the consistency, thickness and color of Crema extracted from stale coffee beans will be seriously affected, and the taste will be greatly reduced.

[2] Baking technology

Requirements: roast raw coffee beans, so that coffee beans show a unique color, aroma and taste. The taste of coffee depends 80% on roasting.

Coffee grinding

Requirements: the thickness of coffee powder must be able to maintain the extraction process between 25-30 seconds. Once the coffee beans are ground, the flavor begins to decline after 2 minutes. In order to keep them fresh, the coffee powder should be ground fresh.

[4] bean grinder

Requirements: the cone type grinding plate is more average and has a longer life than the flat one, and the coffee beans will not be heated during grinding. If the temperature is too high during grinding, the coffee will lose its flavor. At present, the cone type and peace type combined grinding plate is the best design. The bean grinder should be often cleaned and kept clean, and the grinding plate should be updated in time, so that the bean can be in full contact with the surface of the grinding plate.

[5] amount of coffee

Requirements: it usually takes 7 grams of coffee powder and 40 ~ 65 milliliters of water to make a cup of espresso (refers to the amount of water used, not the amount of extraction, here we consider the amount of water absorbed by coffee powder). If you want stronger coffee, you can reduce the amount of water. The correct amount of extraction should be between 1 and 1.25 ounces (flushing out 1 ounce in 25 seconds is the best performance).

[6] packing and powder loading

Requirements: coffee powder needs to be flat and smooth, and coffee powder must be evenly distributed in the filter. Usually, you can first use 3 kg pressure powder, then use 5 kg pressure once, and then use 10 kg pressure to rotate 720 °to make the powder surface smooth and smooth.

[7] water

Requirement: the water used to make espresso must be purified. Some cities need to use trace elements to balance water quality. The water will go bad if it is in the coffee machine for too long. Use a small glass to connect a cup of water in the coffee machine, cool and try, such as the water has gone sour, replace the water in the machine with fresh water.

[8] Water temperature

Requirements: the water temperature must be stable at 88-92 degrees, and the Italian espresso machine must pay attention to the stability of the water temperature. If the water temperature is too low, it will cause insufficient extraction, and the substances inside the coffee can not be fully released, which can only make a cup of espresso with insufficient flavor and sour taste; once the water temperature is too high, excessive extraction will make the coffee bitter and astringent.

[9] pressure

Requirements: water pressure 9-11bar. The general hot water brewing method can only extract water-soluble substances in coffee, while espresso can further extract water-insoluble substances under high pressure. These high pressures will completely emulsify the lipids inside the coffee and dissolve into the water, which is the main source of body. Crema will make espresso taste thicker, making people drink with a "velvety" feeling; and stickiness will form a lower surface tension, more able to invade the taste buds, so that mellow reverberate in the mouth for a long time. The most important sign of a good espresso is that it has a layer of Crema, which is a mixture of fat, water and air in the coffee during the extraction process. Crema should be uniform in color, about 3-5 cm thick, gently shake the coffee cup, this layer of Crema will stick to the wall like thick syrup. If the Crema is dark brown or even black, the coffee is overextracted; if it is yellowish, the coffee is not fully extracted.

[10] Time

Requirement: extraction time 20-30 seconds. It is generally believed in the industry that when extracting espresso, the quality of two cups extracted at the same time is more perfect than that of one cup alone. The extraction time for two 1-ounce cup espresso should be between 25 and 30 seconds. In addition to time, the color of Ruyi espresso begins to fade and the production process should be completed. The goal should be to produce dark red espresso without changing color within 25-30 seconds.

[11] filter handle and filter

Requirements: the filter handle must be kept at the same temperature as the water temperature of espresso. Therefore, the handle should be preheated on the head of the machine.

[12] Machine cleaning

Requirements: if the machine, filter and filter handle are not cleaned, the espresso will smell of rotten oil.

[13] Environmental factors

Requirements: the humidity and temperature of the air will change during the day. Because coffee powder is easy to absorb moisture, the thickness of the bean grinder also needs to be adjusted so that the thickness of the powder can reach 25-30 seconds during extraction.

[14] Italian espresso cup

Requirements: in order to maintain the heat and aroma, the Italian espresso cup has a thick wall and narrow mouth. Espresso cups should be preheated.

Changes in any of these factors will increase or decrease the perfection of espresso. The production of espresso is an art, and the perfect espresso may be a concept rather than a reality. The beauty of espresso lies in its fickleness and difficulty. Because there are so many influencing factors, only the human brain and emotional heart can understand and control the complexity of espresso.