courseriddle2

User Name: You need to be a registered (and logged in) user to view username.

Total Articles : 0

https://www.coffeee.uk/categories/espresso-coffee-machines/8

How Does Machine Espresso Work Machine espresso utilizes 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 forced under high pressure through finely ground coffee The process is similar to making drip coffee However the pressure is the main difference The Group Head The group head is the portafilter that is inserted when you are making espresso It is responsible for dispersing water into the portafilter before controlling the pressure of the extraction There are a variety of types of group head each with its particular advantages and disadvantages Some are designed to provide stability of temperature while others are designed to handle preinfusion Others are made to control the lever Some include a combination like the E61 This is a favorite among baristas as it provides a variety of advantages in one package As you can see in the above image the group head comes with several notches to place your portafilter and twist it manually to lock it in A gasket made of rubber is placed within the notches to create a seal as you insert your portafilter The notches on the head allow for an exact placement of the portafilter which is crucial to ensure an efficient extraction Apart from allowing you easily insert your portafilter the group head is also responsible for maintaining an even temperature This is done by cycling hot water around the portafilter and through the brew basin ensuring that the temperature is at the right level for extraction It is important to note that even a small difference can make the difference between a decent and a excellent espresso The Pump In contrast to piston machines that are manually operated which rely on a lever that pressurize water rotating espresso machines rely upon motorized pumps to supply the nine atmospheric bars of pressure required to extract espresso This pressure is generated by pumping water through a heat exchanger and then through the ground coffee Pumps are generally cheaper and last longer than pistondriven machines However both types of machines may degrade because of excessive use and inadequate cleaning They also add mechanical complexity that can lead to a high price tag on even the simplest models Certain espresso machines do away with the pump completely and use steam pressure to brew espresso The downside is that the same boiler that produces steam also raises the temperature of the water until it reaches boiling and can result in excessive extraction The machines must also constantly rebuild their pressure in between cups This takes energy and time Many espresso machines make use of either a rotary or vibration pump which is a vibration model using a rotating disc to generate the pressure and rotating models that push hot water through the grounds at high speed Both types of machine can make excellent espresso however Rotary machines are quieter and more durable than vibration pumps The Boiler The boiler is the part that heats the water to the optimal temperature for extraction The steam created will eventually reach the portafilter which is the container that holds the espresso coffee grounds The steam is then channeled into the cup During this process the steam causes enough pressure to push the coffee grounds through This creates a foam on top of the espresso This is one of the hallmarks of a good espresso There are three types of espresso machines each with different types of pumps and brew temperature There are a variety of ways in which the brew could be controlled as well as the size of the cup that the machine is capable of making The earliest espresso machines were steam types The earliest espresso machines were steamtype machines This resulted in the coffee tasting bitter and burnt This is the reason Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine The most wellknown espresso maker is a semiautomatic one with an electric pump When people think of espresso machines they picture these machines Semiautomatic machines require you to grind and tamp the beans yourself but the pump regulates the water flow and pressure This is a great compromise between the human touch and the mechanised consistency The Filter Espresso machines usually have a filter that separates the grounds of the coffee from the hot water The filter is also a vital element of the machines temperature control as it helps prevent overheating A filter can also help with flavor because it allows for a longer flowering period This lets the beans let their nuances out and improves extraction However it is important 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 is important This is where the magic happens its what makes espresso taste great The grouphead also called the brew head is where the portafilter the thingy you put the coffee grounds into is placed when youre making espresso Steamdriven espresso machines use hot water heated in an airtight container to create steam The steam then pushes hot water through grounds of coffee under high pressure These types of machines are typically less expensive and simpler to maintain than pumpdriven models However they are not as efficient in their ability to produce the ideal brewing conditions because they operate at 115 bars of pressure The perfect shot requires 910 bar In recent years espresso machines powered by compressed airpump are becoming increasingly popular They utilize an air compressor to push hot water into the grounds and are far more portable than electric steamdriven machines