Basic knowledge of Fine Coffee how to make Espresso well

(1)

Beans-fresh coffee beans with certain quality

The reason why we do not talk about fresh coffee beans is to correct a misunderstanding for brown friends that fresh roasting is not directly related to quality. Freshness is a factor and a premise, but freshness is not good. For example, fresh garbage and fresh poop have nothing to do with quality. So if it is poor quality raw beans and poor baking, no matter how fresh it is.

The quality of coffee beans is the most source and soul in the process of making coffee. Without good quality coffee beans, you can't make good coffee even if you have miraculous technology.

(2)

Machine-- stable cooking pressure

Italian coffee machine uses pump to generate pressure, which is roughly divided into shock type and rotary type. Vibrating type is compact in size and low in cost. For example, a coffee machine with pump pressure 15bar or pump pressure 19bar means that the peak pump pressure can reach 15bar or 19bar, but it is not stable at a certain value, but fluctuates between 1--15bar. The lower the controllability in brewing, the worse the taste stability. Therefore, the vibrating pump is easy to produce miscellaneous and spicy taste, while the rotary pump is more balanced and leads to more sweet flavor.

The rotary pump is mainly used in commercial machines and high-end professional household machines because of its large size. The pressure can be stabilized within a fixed value, from a straight point of view, the pressure curve of the vibrating pump is fluctuating, while the pressure curve of the rotary pump tends to be a straight line, the two are not the same. The use of rotary pump is a major element of stable extraction. In addition, the noise of rotary pump is much lower than that of vibrating pump, and some vibrating pump noise makes people feel unsafe and cheap, and noise can also affect people's mood, so it is not recommended to use vibrating pump coffee machine as a business machine.

At present, the standard of esp brewing theory is 9 ±1 and 9 ±0.5,9 ±2 respectively. Here in order to facilitate the memory and understanding of the individual is set at 9.

Machine-stable brewing water temperature

The higher the brewing water temperature, the lower the sour taste, the higher the bitter and scorched taste, the lower the water temperature, and the higher the acidity, the lower the bitter and scorched taste, so the ideal water temperature should be adjusted according to different beans and formulations, such as lower water temperature for deep baking and higher water temperature for shallow baking. My most commonly used water temperature is 91 degrees.

Water temperature control of most household machines due to the use of heating blocks or smaller boiler water temperature is difficult to stabilize, in the process of extraction, the temperature difference can be up to 10 degrees deviation, even if the operator is more careful, can not overcome this hardware bottleneck. And large-scale mainstream commercial machines (heat exchange type) also have a temperature difference of 4-8 degrees, so there are considerable requirements for the operator's control. For coffee machines with independent PID temperature control in double-boiler and multi-boiler systems, it is easier to stabilize the temperature. With expobar's double-boiler machine, the temperature difference in the extraction process of a cup of esp is only 0.5 degrees Celsius. Higher-end coffee machines, such as synesso, slayer, etc., can control the temperature within 0.1C, while the resolution limit of human taste to the effect of temperature is about 0.3C. So 0.1 degree temperature control is perfect for human beings.

Machine-- an overall good heat conduction material

In the coffee machine hardware that we often talk about, the most common mention is the size of the boiler and the pump (pump). In fact, there are many other things to pay attention to in the coffee machine. The design of different pipes of the material will affect the effect of a cup of coffee. This is also why responsible manufacturers use copper or stainless steel as the main material of the coffee machine. First, copper has good thermal conductivity (to ensure uniform and stable temperature) and ductility, and metal fatigue is not easy to occur even in frequent alternation of cold and heat. 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 and other materials are mostly used in household machines for the purpose of cost saving.

(III)

Grinding-coffee powder that is fine and uniform enough

The extraction of esp has high pressure, so it is necessary to use enough fine powder. In the fine premise as far as possible uniform, so that the coffee pressed powder under the same pressure to get uniform extraction. This requires a bean grinder with good performance. The Italian bean grinder is mainly divided into two kinds of cutter head-parallel cutter head and conical cutter head. The advantage of parallel cutter head is that it can ensure the uniformity of grinding. The powder produced by the tapered cutter head is composed of particles of different sizes, since the coffee powder is uniform, why use the conical cutter head? Because the cone knife grinding uses a low-speed high-torque motor, the grinding is fast and not easy to heat, so the advantage of the cone knife is more obvious when grinding a large number of coffee powder. In addition, some people think that although the cone knife grinding powder is not uniform, it can lead to more levels of flavor, while others say that uneven is easy to lead to miscellaneous smell, so the cone knife itself is a more controversial type, different opinions.

Personally, I am not a pure supporter of conical knives or flat knives. If it is for personal use or does not need a lot of grinding, the calorific value can be ignored. Then I will recommend the flat knife bean grinder, stable, uniform grinding is the premise to ensure quality. If it is a commercial place for grinding a large number of powder, you should choose a cone knife bean grinder with a faster grinding speed and not easy to heat. According to the domestic coffee market, it is wise to use parallel cutters as the mainstream.

Grinding knives are mostly made of high hardness alloy steel. nowadays, some manufacturers offer ceramic or titanium alloy cutterheads, which are not easy to produce high heat, while titanium alloy has more durable properties and can be upgraded according to their own needs.

(4)

Technology-- fixed amount of powder

Fixed amount of powder, only adjust the size of the powder is conducive to the habit of stable extraction, but also convenient to change different formulations of beans to quickly find the best powder thickness. For me, the first use of 18g extraction double, more powder can appropriately improve the success rate, and then continue to reduce the amount of powder with the upgrading of technology and equipment. Because with the improvement of technology and equipment, the same amount of coffee powder can extract more aromatic substances, so as to achieve the goal of producing good coffee with less powder, it is enough for me to make double,14 or 15g, and 9g is used for a single serving.

Beginners, it is recommended to directly use double (double) to start practice, double powder bowl straight tube design is easier to press pressed powder evenly, the pressure of the whole extraction process is relatively more stable, single because of the defects in the design itself, will greatly reduce the success rate of production, so, single does not save beans, do not do well, with less is a waste.

Skill-the strength and technique of pressing powder that suits you.

When you want to present a skill in words, you will find a lot of inconvenience. In the aspect of pressing powder, it can be roughly divided into coarse powder heavy pressure school, fine powder light pressure school and non-powder pressure school, no matter which school it belongs to, it can make different styles of perfect esp. 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 grinders. The advantage of non-pressing powder is that once found, the failure of powder pressing can be avoided. But because there are so many variables in making a cup of coffee, it's okay to be proficient in light pressure and heavy pressure as a new experience, but if you don't press here, you won't recommend it.

No matter which genre you join, remember to try to press pressed powder flat and even.

Some friends are very concerned about whether the extracted coffee pressed powder is dry, which leads to a misunderstanding. We should focus on the flow rate, state, color and taste of the extraction. If we want pressed powder to dry, we just need to grind the pressed powder. More powder can be easily done, but the coffee may not be good.

Technology-fixed extraction quantity

The more factors we can control, the more likely we are to get a good cup of coffee.

Although it is possible to judge whether to continue or stop the extraction according to the state of coffee outflow, breaking through the framework of the theory requires enough brewing experience, and giving yourself a stable range at the beginning will make you progress faster.

More widely used amount of extraction

Single espresso 25-30 seconds extraction of 25-35ml Coffee

Double espresso 25 seconds-30 seconds extraction of 45-55ml Coffee

The timing of extraction starts not from the moment the coffee comes out, but from the moment the coffee-making switch is turned on.

Conclusion: beans, technology, machine, grinding are all indispensable. We do not agree with the extreme point of view of exaggerating one link and neglecting other links. Of course, if you can add a heart that loves coffee, you will do better.