How to do Espresso well

(i)

Beans-fresh and quality coffee beans

The reason why I didn't say fresh coffee beans is to correct a misunderstanding for coffee friends here. Fresh roasting is not directly related to quality. Freshness is a factor, a premise, but freshness is not equal to good, such as fresh garbage, fresh poop, and quality are not related. So if it is poor quality raw beans and poor baking standards, no matter how fresh it is, it is useless.

The quality of coffee beans is the most source and soul in the process of making coffee. Without good quality coffee beans, even if there is a divine machine, the technology of grinding gods cannot make good coffee.

(ii)

Machine-Stable brewing pressure

Italian coffee machine uses pump to generate pressure, roughly divided into vibration type and rotary type, vibration type compact size, low cost and more used in household machines, such as a household coffee machine, pump pressure 15bar or pump pressure 19bar, which means that the pump pressure peak can reach 15bar or 19bar, but not stable at a value, but fluctuates between 1--15bar. The lower the controllability in brewing, the worse the stability of taste. Therefore, vibration pump machine is easy to produce mixed taste and spicy taste, rotating pump machine is more balanced, leading to more sweet flavor.

Rotary pumps are mostly used in commercial machines and high-end professional household machines because of their large size. The pressure can be stabilized at a fixed value. From a straight point of view, the pressure curve of the vibrating pump fluctuates, and the pressure curve of the rotating pump tends to be a straight line. The two are not the same. The use of the rotating pump is a major factor in stable extraction. In addition, the rotary pump noise is much lower than the vibration pump noise, some vibration pump noise gives people a sense of insecurity and cheap, noise will also affect people's mood, so it is not recommended to use the vibration pump coffee machine as a business machine.

Current esp brewing theories range from 9±1 to 9±0.5 and 9±2. For ease of remembering and understanding, the individual is designated 9.

Machine--Stable brewing water temperature

The higher the brewing water temperature, the less sour coffee, bitter and burnt, the lower the water temperature, the higher the acidity, bitter and burnt, so the ideal water temperature should be adjusted according to different beans and recipes, such as deep roasting with lower water temperature, light roasting with higher water temperature. My favorite water temperature is 91 degrees.

Most household machines are difficult to stabilize due to the use of heating blocks or smaller boiler water temperatures. In the process of extraction, the temperature difference can reach 10 degrees, even if the operator is careful, it cannot overcome this hardware bottleneck. Large mainstream commercial machines (heat exchange type) also have a temperature difference of 4-8 degrees, so there are considerable requirements for operator control. Double boiler and multi-boiler system with independent PID temperature control coffee machine, temperature control is relatively easy to achieve stability, take Expobar double boiler machine can make a cup of esp extraction process only 0.5 degrees of temperature difference, higher-end coffee machine such as synesso, slayer, etc., can control the temperature in the range of 0.1 degrees, and human taste for the impact of temperature resolution limit is about 0.3 degrees, so 0.1 degrees of temperature control for humans is perfect.

Machine--Overall good heat conduction material

In the coffee machine hardware that we often say, the most commonly mentioned is the boiler size and pump (pump). In fact, there are many coffee machines to pay attention to, and the design of different pipes of materials will affect the effect of a cup of coffee. First, copper has good thermal conductivity (to ensure uniform temperature stability) and ductility, even in the frequent alternation of cold and hot metal fatigue is not easy to occur. Stainless steel is more hygienic and durable. Because stainless steel appeared relatively late, many manufacturers still use traditional copper to make coffee machines. Plastics, aluminum These materials are mostly used in household machines for cost-saving purposes.

(iii)

Ground-coffee powder that is sufficiently fine and uniform

The extraction of esp has a higher pressure, so use a fine enough powder. Under the premise of fine as much as possible uniform, so that the coffee powder under the pressure of uniform extraction. This requires a good bean grinder. Italian grinding machine is mainly divided into two kinds of cutter disc-parallel cutter disc and conical cutter disc, the advantage of parallel cutter disc is to ensure the uniformity of grinding. The powder ground by the conical cutter is composed of particles of different sizes. Since the coffee powder is uniform, why use the conical cutter? Because the cone mill uses a low-speed high-torque motor, the grinding is fast and not easy to generate heat, so the advantage of the cone mill is obvious when grinding a large amount of coffee powder. In addition, some people think that although the cone knife grinding is uneven, it can lead to more layers of flavor, and some people also say that uneven is easy to lead to miscellaneous flavor, so the cone knife itself is a controversial type, different opinions.

Personally, I am not a pure supporter of cone knife or flat knife. If it is for personal use or does not require a lot of grinding, the calorific value can be ignored. Then I would recommend a flat knife grinder, stability, uniform grinding is the premise of quality assurance. If it is a commercial place with a large amount of grinding, you should choose a cone knife grinder with faster grinding speed and less heat. According to the domestic coffee market, parallel cutter head as the mainstream is more sensible.

Sharpeners are mostly made of high-hardness alloy steel. Nowadays, some manufacturers also introduce ceramic or titanium alloy cutter heads. Ceramic cutter heads are not easy to produce high heat. Titanium alloy has more durable characteristics and can be upgraded according to their own needs.

(iv)

Technology--Fixed amount of powder

Fixed amount of powder, only adjust the powder thickness is conducive to the habit of stable extraction, but also convenient to change different formula beans quickly find the best powder thickness. Take me for example, the earliest use of 18g extraction double, more powder can appropriately improve the success rate, and then with the upgrading of technology and equipment continue to reduce the amount of powder used. Because when the technology and equipment are improved, the same amount of coffee powder can extract more aromatic substances, so as to achieve the purpose of good coffee with less powder, I now make double, 14 or 15g is enough, and a single serving is 9g.

Novice entry, it is recommended to use double (double) to start practice, double powder bowl straight design is easier to flatten the powder cake, the pressure of the whole extraction process is relatively more stable, single because of the design itself defects, will greatly reduce the success rate of production, so that a single portion does not save beans, do not do well, use less is also a waste.

Technique--suitable for your own powder pressing strength and technique

When it comes to presenting a skill in words, there are many inconveniences. In terms of pressing powder, it is roughly divided into coarse powder heavy pressure pie, fine powder light pressure pie and no pressure powder pie. No matter which genre you belong to, you can make perfect esp of different styles. Among them, the school of non-pressing powder is the most minority and difficult to master, because it takes a lot of energy and time to find the critical point of powder quantity and powder thickness, and has certain requirements for bean grinder. The advantage of not pressing powder is that once found, it can avoid the failure of pressing powder. But because there are so many variables in making a cup of coffee, it's not a bad idea to master light pressure and heavy pressure as a new experience, but here it's not recommended if you don't press pie.

No matter which genre you join, remember to press the cake as evenly as possible.

Some friends are very concerned about whether the coffee cake after extraction is dry, which enters the misunderstanding, we should focus on the extraction flow rate, state, color, taste, want to dry the cake, as long as the powder is coarse, put more powder can be easily done, but the coffee may not be good.

Technology--fixed extraction quantity

The more variables we can control, the higher our chances of getting a good cup of coffee.

Although you can judge whether to continue or stop extraction according to the state of coffee outflow, breaking through the theoretical framework requires sufficient brewing experience. Giving yourself a stable range at the beginning will make you progress faster.

More widely used extraction volume

single espresso 25 seconds-30 seconds extraction 25-35ml coffee

double espresso 25 seconds-30 seconds extraction 45-55ml coffee

The timing of extraction does not start from the moment the coffee flows out, but from the moment the coffee making switch is turned on.

Summary: beans, technology, machinery, grinding regardless of the order, none of them, do not agree with the extreme view of exaggerating a link to ignore other links. Of course, if you can add a heart that loves coffee, you will definitely do better.