The production of Italian espresso Espresso

Making a good Espresso can be a challenge for both coffee lovers at home and the experienced Barista in the cafe. Below, we will discuss the various factors that affect Espresso.

1. Coffee beans

There is no good Espresso without good coffee beans. Coffee beans must be fresh. As far as Espresso is concerned, the consistency, thickness and color of the coffee extracted from stale coffee beans will be seriously affected, and the taste will be greatly reduced.

2. Baking

Roast the raw coffee beans to make the coffee beans show a unique color, aroma and taste. The taste of coffee depends 80% on roasting. (for details, see: coffee bean baking methods and principles)

3. Coffee powder

The coffee powder must be thick enough to keep the extraction process between 25 and 30 seconds. Once the coffee beans are ground, the flavor can be preserved for no more than an hour. In order to keep the coffee fresh, the coffee powder should be ground fresh.

4. Bean grinder

Cone-shaped grinding plates are more average and have a longer life than flat ones, and coffee beans are not 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. Coffee quantity

It usually takes 7 grams of coffee powder and 40 to 65 milliliters of water to boil a small cup of Espresso. 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. Powder loading and pressing

Coffee powder needs to be flat and smooth, and coffee powder must be evenly distributed in the filter. Usually you can use 5 pounds of pressure powder once, then 30 pounds of pressure once, and then rotate 720 °with 20 pounds of pressure to make the powder surface smooth and smooth.

7. Water

The water used for 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

The water temperature must be stable at 90 °±5 °. When choosing Espresso machine, we must pay attention to the stability of water temperature and 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, so that you can only cook 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. Water pressure

The pressure of water is 9 ±2 atmospheric pressure (bar). The general hot water brewing method can only extract the water-soluble substances inside the coffee, and Espresso can further extract the water-insoluble substances by high pressure. These high pressures will completely emulsify the lipids inside the coffee and dissolve it into water, which is the main source of "body". Emulsification 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 light camel-colored emulsion (Crema), which is a mixture of fat, water and air in the coffee during the extraction process. The emulsion should be uniform in color, about 3 cm to 5 cm thick, shake the coffee cup gently, and this layer of emulsion will stick to the wall like thick syrup. If the emulsion is dark brown or even black, the coffee is overextracted; if it is yellowish, the coffee has not been fully extracted.

10. Extraction time

The extraction time was 30 ±5 seconds. It is generally believed 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 making two 1-ounce cup Espresso should be between 25 and 30 seconds. In addition to time, if the color of the Espresso begins to fade, the production process should be completed. The goal should be to produce a dark red Espresso within 25-30 seconds without changing color.

11. Filter handle and filter

The filter handle must be kept at the same temperature as the water temperature used to make the Espresso. Therefore, the handle should be preheated on the head of the machine.

12. Machine cleaning

If the machine, filter and filter handle are not cleaned, the Espresso will smell of rotten oil.

13. Environmental factors

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.

18. Espresso Cup

In order to maintain the heat and aroma, the Espresso cup has a thick wall and a narrow mouth. Espresso cup should be preheated.

The change of any of these factors will increase or decrease the perfection of Espresso. The production of Espresso is a kind of art, and the perfect Espresso may be just a concept and cannot be realized. The beauty of Espresso lies in its fickleness and difficulty. Because there are so many influencing factors, only the human brain and the emotional heart can understand and control the complexity of Espresso.