Many coffee lovers appreciate the possibility of preparing their favorite drink in coffee machines. It’s really fast, convenient and simple. For those who are wondering how a coffee machine can prepare a cup of coffee in just 1-2 minutes, below we will describe how various types of devices are arranged and work.
General principle of operation
To make coffee by hand, you first need to roast and grind the beans. If using a coffee machine, all these steps can be skipped. To understand how a coffee machine works, let’s look at how it makes coffee step by step.
- To prepare a coffee drink, you need hot water, but in no case boiling. The machine itself heats the water to the optimum temperature of 80-90 0FROM.
- Coffee for the drink is used ground or in special sealed capsules (already roasted and ground). Due to their tightness, the capsules retain its taste and aroma for a long time.
- Inside the machine, these two ingredients are combined and turn into an invigorating aromatic drink at the exit.
In the case when you need to prepare a cappuccino or latte, you will need to add one more ingredient – milk, to decorate the drink with a “cap” of thick foam.
The general schemes of all coffee devices are identical and consist of approximately the following set of components:
- Heating element.
- Tank with lid.
- Safety valve, to control the pressure in the device.
- The filter that receives the steam.
- Flask for brewed coffee.
This set may vary depending on the manufacturer. For example, DeLonghi manufactures coffee machines with two pressure pumps, with which you can prepare both cappuccino and espresso at the same time. In addition, if we consider the electrical circuit of the DeLonghi coffee machines, we can see that they do not always have heating elements. Sometimes (in simpler models) the steam generated from boiling water is used to make coffee.
Types of coffee machines and the principle of their operation
To prepare coffee drinks at home, you can choose one of the following types of coffee makers:
Let us consider in more detail the device and the principle of operation of each type.
drip coffee maker
The device is the simplest in terms of design: in such devices, coffee is brewed without steam or boiling water pressure. Allows you to brew strong Americano coffee. Inside the machine body there is a heating element, a water tank and a filter compartment for filling ground coffee. A container with a handle and a measuring scale (coffee pot) is installed from below. The principle of operation of the device consists in the drip passage of heated water through the filter. As a result, the water that seeps through the filter, saturated with taste, aroma and color, flows into a glass or plastic coffee pot.
Depending on the power of the coffee maker, the time for preparing the drink varies. On average, coffee is prepared in a drip coffee maker for about 5 minutes.
Care consists of periodic cleaning/replacing the filter. Models can use disposable or reusable filters. When choosing such a device for your home, you should pay attention to the following points.
- Power – for weak coffee, you need to choose a device with a higher power, and for a strong coffee drink, you should buy a device with a low power.
- Flask material (glass or plastic). Glass does not absorb odors, while plastic is more durable.
- Flask dimensionswhich depend on the required amount of brewed coffee.
- filters, which are of three types: disposable; gold – for long-term use; nylon filters that can be used up to 60 brewing times.
Geyser coffee maker
These devices both electric and non-electric, which can be placed directly on the hob or just on an open fire. Unlike the previous coffee machine, here the principle of operation is exactly the opposite. Water in these devices is supplied from the bottom up, identical to a geyser, and pours coffee. After that, it, saturated with coffee, is poured into a special flask.
The volume of geyser coffee makers is small. They look like porcelain coffee pots. What is wonderful, coffee does not “run away” from the device like from a cezve, but of course you need to look after it.
Composed geyser coffee maker from two containersinterconnected like an hourglass. In the central area, in a narrow channel, there is a compartment for coffee. When the water in the lower compartment boils, it rises and makes its way up the narrow passageway, brewing coffee along the way. In the upper container is already almost ready drink.
Capsule coffee machine
The device prepares a drink from ground coffee enclosed in a special food shell, the so-called capsule. The design of the device includes a water tank, a pump that supplies water to the boiler with a coffee capsule, a heating element and a container into which the used capsules are discarded.
The coffee maker works as follows:
- a pressurized pump sucks water from the tank into the boiler;
- in the cooking compartment, water is heated to a temperature of 85-90 ° C;
- hot liquid penetrates through the lower and upper holes into the capsule, is saturated with the aroma of coffee, acquires a dark shade;
- the capsule system provides filling of capsules into the boiler and ejection of the waste cake into the container.
By means of the control unit located on the body of the device, the functions of dispensing portions of the drink for large and small cups are configured. Care of such a coffee maker consists in periodic cleaning the container with spent capsules.
Carob coffee maker
The carob-type device is equipped with a removable holder (horn), where ground coffee is poured. Rozhkovy models of coffee machines are equipped with indicators and buttons for controlling the process of making coffee. Many models are also equipped nozzle – cappuccinatore for frothing milk when making cappuccino.
Some skill is required from the user to compact the coffee powder poured into the holder into a tablet using tempera. The coffee maker easily copes with the preparation of espresso coffee. The essence of the work of the carob apparatus is as follows.
- Under pressure, hot water (steam) is fed through a tube into the holder.
- Passing through the coffee briquette and the filter, the liquid absorbs coffee extracts.
- The finished drink is sent to a cup placed under the tap.
Drink strength depends on the degree of grinding and compaction of the powder. The finer the grind and the more compacted the coffee, the stronger the drink. An indicator of the quality of brewed coffee is a thick, stable foam saturated with gas bubbles. The thicker the foam, the slower the drink cools down.
The quality of the brewed coffee is affected by the material from which the holder is made. In a metal cone, the drink turns out to be thick, with a lush and rich foam. In a plastic holder, the consistency of the drink is watery, the foam is light, and the taste is sour, regardless of the type of coffee used. This happens because the raw material in the plastic holder warms up less than in the metal counterpart.
Rozhkovy coffee makers are of two types, depending on the pressure in them.
- Up to 4 bar, in which coffee is brewed slowly and it turns out strong and full-bodied.
- Up to 15 bars, in which coffee is prepared quickly and turns out soft and tender.
Caring for the device is releasing the horn. The used coffee briquette is thrown away, and the holder must be washed in running water. Otherwise, when brewing the next portion of the drink, the remaining particles of old coffee can significantly spoil the taste.
Automatic coffee machines
The process of making coffee in an automated machine does not require human intervention. The user only has to perform a single button press to initiate a beverage preparation cycle according to the selected program. Automation independently manages all stages of preparation: from grinding to serving a portion of the drink into a cup.
The machine is capable of more than 10 functions, including grinding grain, discarding grounds in a special container, whipping milk foam, setting the volume of a serving, the strength of the drink and others. The machines are equipped with a grain container, a built-in coffee grinder, a cappuccinatore, a container for collecting coffee pomace, a compartment for compacting ground raw materials into a tablet, and a dispensing tank. Inside the case there is a water tank, a pump, a heat exchange system, a boiler, pipes for supplying water and steam.
Some household vending machines are equipped with a convenient display that reflects the step-by-step process of brewing a drink. Some manufacturers supplement the devices with convenient functions for heating dishes, automatic descaling and others.
When the device is turned on, the system will check the readiness of all technological units for operation. The signal of successful completion of the system poll is the green light of the indicator. The user just needs to select the coffee preparation program: espresso, americano latte, cappuccino, and the machine will start the desired technological chain. The prepared drink is served in a cup or glass, after which the machine will stop and wait for a new command.
Combined coffee machines are not cheap, but the process of preparing drinks in them is fully automated.