Guide to Semi-Automatics Espresso Machines
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Semi-Automatic Espresso Machines Becoming your own barista is not that far away! With semi-automatic espresso machines you can become an at home barista. Semi Automatics have the advantage of an automated pump which gives you consistent pressure of the water on the grounds. It is semi-automatic and not fully because you control the length of the extraction by turning on and off the pump switch. When you decide that enough water has flowed through the grounds, you shut the pump, thus ending your shot. Grinding and tampingright will affect the quality of your shot. You need to have a fine grind and the tamping has to be
done with pressure on your part to create a firm ‘puck’. Burr grinders are best for grinding your coffee beans to a fine and consistent grind. Regarding tamping, the harder you tamp, the denser the grinds will be. You need the perfect tamp so that the water won’t flow too fast or too slow through the grinds giving you an under-extracted or over-extracted coffee. 30 lbs of pressure is generally needed to get the right tamp. (This is however not necessary if you have a pressurized portafilter - which is explained in a previous article). Many semi-automatics include a cup warmer. Preheating your cups before brewing helps keep the coffee temperature of your shot. It is best if you also preheat your portafilter. Frothing is an art of its own. The steam wand attachment included on semi-autos is great for preparing milk based coffee drinks such as cappuccinos and lattes. Learning to steam and foam the milk takes some practice. The price range on semi automatics varies greatly but generally the higher the price, the more features you are getting. Pricing starts from around $60 and can go as high as $4,000!
Different types of Boilersin Semi Autos heat the water in different ways. There is the Single Boiler, Dual Use, which means there is one boiler that does both the heating for brewing and steaming with the use of two thermostats. Going from steaming to brewing will always take a bit of time as the boiler adjusts the temperature. Thermoblock machines have a boiler with water that is at a consistent temperature for brewing, while a thermoblock is used for steaming, eliminating the wait time that is the norm with single boilers, dual usage. The Heat Exchange Semi Automatics have a boiler with a pipe going through it. Water in the boiler is at a constant steaming temperature while the pipe/heat exchanger pulls water from the resorvoir which is then heated by the steam in the boiler. This allows for steaming and brewing at the same time. The best option of all is Dual Boiler espresso machines which are much more expensive. These have two separate boilers, one for steaming and one for brewing and provide the most stable temperatures for both. Most commercial-quality espresso machines have a rotary pump. Rotary pumps generally require a plumbed in machine as letting the pump run dry can be damaging since they have a need for constant pressurized water. It handles higher volume espresso extractions. Semi-commercial machines and high-end home espresso machines usually have a vibratory pump. They can handle up to 40-50 extractions per day and are therefore better suited for lower volume use. They may not be as consistent as rotary pumps but they are cheaper and easier to replace. Getting perfect results from your new semi automatic machine may require some practice but with time you will get a handle on it. It will prove worth it with the delicious espresso and specialty coffee drinks you create in the comfort of your home. |
