I am here to recommend a machine to you again. However, whether this article is a good one or a bad one, you can make your own conclusion after reading it.

After all, I am also a heavy coffee addict. I have coffee machines in the store and a lot of coffee utensils at home. Many friends have asked me, how should I choose a coffee machine for my home? In fact, this is a very broad question. If I want to talk about it in detail, I guess it will take more than an article to finish.

However, most people who ask this question may not even know the types of coffee and the differences between them. Well, let me start from here and briefly talk about coffee machines.

Types of coffee

Based on the different brewing methods, I roughly divide coffee into two categories: Italian coffee and American coffee.

1. Italian coffee

Italian coffee is actually a method of extracting coffee liquid in a short time by means of high temperature and high pressure. Cappuccino, latte, mocha, and macchiato that we often hear about actually belong to this category. They are all based on Italian espresso , with milk, syrup or cream added, and are often called "fancy coffee".

The following picture shows the difference between these fancy coffees:

The differences and connections between various fancy coffees

2. Americano

There are two types of American coffee. One is made with espresso as the base, with a lot of water (hot or iced). The other is made directly with an American coffee machine, which does not require high temperature and pressure, and uses hot water to extract coffee liquid through coffee powder. For the sake of distinction, I will classify the first type of American coffee as "Italian coffee" below, because after all, it is made with espresso as the base. American coffee refers to the drip extraction method.

American drip coffee machine

Types of coffee machines

Coffee machines can be divided into Italian coffee machines and American coffee machines. The classification of American coffee machines is relatively simple. Let’s talk about Italian coffee machines in detail.

Espresso machines can be divided into two types : fully automatic espresso machines and semi-automatic espresso machines . Let's first talk about the most common semi-automatic espresso machines. This type of machine is the most frequently seen in coffee shops. Although the brands have many differences in appearance, the principles are similar.

This type of machine is the most common type you see in coffee shops.

Coffee making process

1. The process of making Italian coffee

Grinding - Pressing - Extraction - Milk Foaming - Latte Art

2. The process of making American coffee

Grinding - put into the machine for dripping

Semi-automatic coffee machines often have a steam generator, also known as a "milk frothing stick". Usually, we see baristas using this device to heat milk and froth milk when making coffee. As shown in the following figure:

There are two key steps in an espresso machine: one is to extract the coffee liquid, and the other is to make steam. Although the quality of coffee is related to many factors, and some of them are subjective, there are still certain standards for the production of espresso: it requires the extraction pressure to be 8-9 Pa atmospheric pressure, 92 degrees hot water, 18g of coffee powder, and 45-60ml of coffee liquid to be extracted in 25-30 seconds. Then we require that when the coffee machine is extracting, the water temperature should remain basically unchanged or rarely fluctuate, the pressure should also remain stable, and steam can be produced at the same time (because as time goes by, the oil content of the coffee liquid will decrease and the caffeic acid will precipitate, so you can't wait too long before drinking it). Steam is also required to be at least stable and sufficient, and the coffee machine should be able to heat milk quickly.

Espresso being extracted

Let's talk about the heating module of the espresso machine

The heating module of the coffee machine corresponds to two key steps: extraction and steam. There are two main heating methods: one, heating block, two, boiler. The difference between heating block and boiler can be simply understood as the difference between instant electric water faucet and storage electric water heater . If you want to say which one has a more stable temperature, of course the temperature of the boiler is more constant.

There are several types of boilers. Let's take a brief look at them:

1. Mother-child boiler

The heat exchange mother-and-child boiler structure was first established by FAEMA in 1961. Now most low-end and mid-range commercial coffee machines use this boiler. The general principle diagram is as follows: the water in the large boiler is heated, the cold water is used to extract coffee through the coil inside the large boiler, and the large boiler outputs steam for frothing milk. Its structure determines that the extraction temperature is difficult to control accurately and stably.

2. Double boiler/multiple boilers

Double boilers refer to a boiler that contains an extraction boiler and a steam boiler, and multi-boilers refer to each brewing head being equipped with an independent coffee boiler. Most double boilers and multi-boilers are usually equipped with a PID temperature control system. This solves the problem of the temperature of the mother and child boilers being difficult to control, but of course the price will be more expensive.

Tips: What is PID temperature control system?

The full name is Proportional Integral Derivative, which literally means proportional integral derivative. Traditional temperature control uses temperature as a trigger condition, such as when the temperature is lower than a certain temperature to start heating. This will cause a delay in heating and the water temperature will fluctuate in a larger temperature range.

The PID system measures not only the real-time water temperature, but also calculates the rate of change of the water temperature, thus maintaining the water temperature in a relatively constant range with only minimal fluctuations.

The larger the boiler, the greater its ability to maintain a constant temperature and the greater its ability to produce continuously.

However, the larger the boiler, the longer it takes to preheat the coffee machine. In addition, machines equipped with dual boilers/multiple boilers and with extraction boilers that meet the standards are not cheap. At this point, there is no such thing as cost-effectiveness, and there is no illusion of having both performance and speed.

The Heart of an Espresso Machine: The Pump

Just now we talked about the standard of espresso, which includes the extraction pressure. According to the standard of coffee making, what is needed is continuous and stable pressure (of course, there are machines that can play with variable pressure, which is a more advanced technique and we will not mention it here).

There are two main types of pumps: rotary pumps and vibration pumps.

1. The principle of the vibration pump is similar to that of an air pump. Many machines are marked with "maximum pressure of 15 bar or 20 bar". When working, there is half a pressurized period and half an idle period, so the extraction pressure is just an average value of the extraction water pressure supplied by the pump. The schematic diagram is as follows:

Its characteristics are low price, small size, simple structure. During continuous extraction, the motor needs to be idle for a period of time because it needs to dissipate heat. And its pressure is related to the coarseness and uniformity of the coffee powder. Vibration pumps are mostly used in home coffee machines or low-end commercial models.

2. Rotary pump: Compared with the vibration pump, it is large in size and expensive, but of course it has obvious advantages, such as low noise, easy adjustment of extraction pressure, and ability to maintain stable pressure. Most commercial models are equipped with rotary pumps.

Recommendations for semi-automatic espresso machines

By now, you should have figured out that you really get what you pay for when it comes to choosing an espresso machine. Speaking of the machine alone, the key factors that affect the quality of coffee are the heating module and the type of pump. Of course, it's not just the coffee machine that determines the quality of coffee, the grinder is also a very important factor. It's a long story to talk about grinders, so we'll talk about it next time. But I just want to explain it in one sentence: a standard entry-level grinder costs at least 2,000 yuan, and there's no upper limit.

OK, now that I have talked about the impact of the machine on coffee quality, let me talk about daily use scenarios: the boiler machine needs to be preheated for at least 20 minutes to 30 minutes, and it needs to be cleaned daily after making coffee, and routine maintenance is required after a period of time. The grinder also needs to be cleaned and maintained regularly.

Don’t be in a hurry. Friends who are interested in purchasing an espresso machine, please do a few questions and answers first, and then I will recommend the coffee machine model.

1. Are you particular about the taste of coffee? Yes → Question 2, No → A

2. Do you have enough budget? Yes → 3 questions, No → 4 questions

3. Do you have time? Yes → Question 5, No → B

4. Can you accept coffee with a lighter taste? Yes → C, No → B

5. Do you drink at least 5 cups of coffee a day? Yes → Question 6, No → B

6. Do you like making coffee yourself? (Including a series of cleaning and maintenance of the machine) Yes → D, No → B

A. You can buy any machine according to your budget, whether it is a capsule coffee machine or an American drip coffee machine. Since you are not particular about the taste of coffee, that is to say, you cannot taste the difference between the coffee made by these machines, then you can buy one based on your preference.

B. It is not recommended to buy an Italian coffee machine

C. It is recommended to use hand brewing and other methods. You can still drink good coffee if you have good skills.

D. Finally, you have passed the screening, have enough budget, have time, like to make coffee and drink several cups every day, then go shopping happily! Please see my recommendations below.

1. Entry level

According to the standards I mentioned before, the machines at this level are actually not up to standard, and are quite different from those in boutique coffee shops. However, considering that some of my friends have just gotten out of the toy machine level of less than 1,000 yuan (no disrespect meant), and always feel that hand-brewed siphon coffee is too bland, and still want to try to draw some coffee art, I will recommend a few machines of this level to you.

Maxtor em-19-m3: Price 3k, extraction temperature is relatively stable, steam is also good, with PID temperature control. Very cost-effective (in fact, Maxtor's machines are all very cost-effective)

Huijia kd-210: heating block, dual vibration pump, PID temperature control. The workmanship is better than Maxtor 19, and the appearance is a matter of opinion. The cost performance is higher than the 230 and 270 of the same series. Price 3k-3.6k

2. Want a better upgraded version

Huijia kd-310: Although it has a heating block and a vibration pump, it has been greatly improved compared to its previous generation of machines. There are three heating blocks, so the extraction temperature can still be maintained after use (in a home environment, it will not work if you want to produce cups continuously). For home use, the machine preheats quickly after startup, and it takes almost a few minutes. The steam is also large. The price is about 6.8k.

Maxtor em30: At this price, it is very cost-effective to have a dual boiler + rotary pump. The size of the dual boiler is also suitable for steam drying, but the preheating time is longer, and it needs to be connected to the water pipe, and there is no water tank. For home use, you still need to consider the location. Except for the workmanship, it can be said that the performance exceeds the price. The price is also about 6.8k.

Oscar 2nd Generation: Mother-child boiler, vibration pump, the water temperature of extraction is difficult to control, which is determined by its structure. However, Oscar's steam is indeed stronger. The price is around 6k.

The coffee machines with higher prices are almost tens of thousands, such as Aibo E61 high-end version (9k), Lasspazara S1 (17k), Rocket R58 (23k), LAMARZOCCO mini (35k), LAMARZOCCO GS3 (55k)... In fact, I don't recommend them for home use. Machines like LAMARZOCCO GS3 cost 50,000 yuan. How many cups can a home use produce in a day? How long does it take to preheat a cup of coffee? In addition to startup and debugging, daily cleaning, regular maintenance, and a grinder that matches its performance, it's better to go out and drink. However, if you say, I don't care about the money, then just ignore what I said and buy the more expensive one. It's always right.

LAMARZOCCO GS3, I suggest you don’t look at it or try it. It is a legendary product and a dream machine that all coffee lovers would want to own.

LAMARZOCCO gs3, image source: Internet, please delete if infringed

The above is just my personal opinion, and does not represent any authority or the interests of any brand. Welcome everyone to discuss and welcome different voices and opinions.