14 Businesses Doing A Great Job At Machine Espresso
How Does Machine Espresso Work?
Machine espresso employs precise pressure and incredible filter technology to produce the delicious coffee we enjoy. But how exactly does it work?
To make an espresso hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.
The Group Head
As the name implies the group head is the place you place your portafilter while brewing espresso. It disperses the water into the portafilter, and then controls the pressure of the extraction. There are numerous kinds of group heads each with distinct advantages and disadvantages. Some are designed for temperature stability while others are built to handle pre-infusion. Others are built to control the lever. espresso coffee machine are a combination, like the E61. This is a favorite among baristas as it provides a variety of benefits in a single package.
As you can see from the image above the group head has a number of notches. You can place your portafilter in these notches and then twist the head to secure it. A gasket made of rubber is positioned in the notches to create a seal when you insert your portafilter. The notches permit the precise placement of the portafilter. This is vital for an accurate extraction.
The group head not only allows you to insert your portafilter easily but also maintains the same temperature. It does this by cycling hot water through the brew basket and around the portafilter, ensuring that it's always at the correct temperature to extract. This is vital, because even a few degrees can mean the difference between good and great espresso.
The Pump
The motorized pumps used in rotary espresso machines provide the nine atmospheric bars of pressure required to extract espresso. This differs from manual piston machines which use levers. The pressure builds by removing tap water from a reservoir and pumping it through a heat exchanger prior it is shot through the ground coffee inside the group head.
Pumps are generally less expensive and last longer than piston-driven machines. However, both types of machines are susceptible to degrading because of excessive use and poor cleaning. They also increase the complexity of mechanical systems, which can result in the cost of even the most basic models.
Some espresso machines use steam pressure instead of a pump to make espresso. This could lead to over-extraction since the boiler that produces steam also causes the water to boil. Additionally, these machines frequently have to restore their pressure between cups, which takes time and energy.
A large majority of espresso machines employ a rotary or vibration pump. A vibration model utilizes a vibrating disk to generate pressure, while a Rotary model pushes hot coffee through the ground at high speed. Both models are capable of producing excellent espresso, but the rotary pumps are quieter, and more durable than vibration pumps.
The Boiler
The boiler is the one that heats the water to the perfect temperature for extraction. The resultant steam then reaches the portafilter which holds the ground espresso coffee, and is then pumped down into the cup. The steam creates enough pressure to push the grounds of coffee through. This produces a layer of crema that is then poured over. This is one of the hallmarks of a great espresso.
There are three kinds of espresso makers. They differ in the type of pump they employ and the degree of heat that the brew is. There are different ways that the brew may be controlled and the size of the cup that the machine can produce.
The first espresso machines were steam types. The first espresso machines were steam types. The coffee tasted bitter and burnt. This is the reason why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.
The most well-known espresso maker is a semi-automatic machine that has an electric pump. These are the images people have when they imagine an espresso machine. Semi-automatic machines require you to grind and tamp the beans yourself however the pump controls the water flow and pressure. This is a great compromise between the human touch and the mechanised consistency.
The Filter
Espresso machines typically have filters that separate the grounds of coffee from hot water. The filter is also an essential component of the machine's temp control, since it helps to prevent overheating.
A filter can also help with flavor since it allows for a longer flowering phase. This allows the beans to let their nuances out, and also allows for better extraction.
However it is crucial to keep in mind that even a great filter could result in a bad cup of coffee as the quality of the beans and extraction are vital.
It's in this area that the magic happens. This is what makes espresso taste so good. The grouphead (also known as the brewhead) is where you put the portafilter - the thingy that you put the grounds of coffee into when making espresso.
Steam-driven espresso machines make use of hot water that is heated inside an airtight container to make steam. The steam then pushes hot water through coffee grounds under high pressure. These kinds of machines are generally cheaper and easier to maintain than pumps-driven models. They are however limited to create the perfect brewing conditions as they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.
In recent years, compressed air pump-driven espresso machines have been gaining popularity. They use an air compressor to push hot water through grounds and are significantly more portable than electric steam-driven machines.