Choosing an Espresso Machine - Features
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Now let’s dig a bit deeper into the vast world of Espresso Machines. There are a couple of types of espresso machines used in homes. The most common are steam-driven, pump driven and piston-driven.
Piston-driven: These machines have a lever which needs to be manually operated. By pulling the lever, hot water is pressurized and then goes through the grounds. The quality of the shot depends on the skill of the operator. Steam-driven: Water is forced through the coffee by using steam pressure. The steam-driven espresso machines are usually cheaper models since these machines cannot produce enough pressure and proper temperature of hot water for an authentic shot of espresso. Pump-driven: A motor-driven pump forces the water through the coffee grounds. The pump-driven machines provide adequate pressure for a good extraction which is not as possible with steam-driven espresso machines. Pump driven machines have variants: Single Boiler, Dual Use Espresso Machines: These machines have one boiler for both brewing and steaming. The boilers have two thermostats that work one to heat water to brewing temperature and another to boil water for steaming milk. Since the temperature needed for brewing is less than the temperature for steaming, the machine requires time to shift from one mode to another. To go from steaming to brewing, you need to wait for the unit to cool or need to run water so that the temperature of the water is lowered for brewing. Thermoblock Espresso Machines: These machines feature one boiler with water that remains at a constant temperature for brewing
and then a separate thermoblock for quickly heating the water set at brew temperature to steaming temperature. The thermoblock is a block of metal which heats up water as it moves through a tube that is encased in the block. With these machines you cannot brew and steam at the same time; however the advantage is that there is no waiting time between pulling a shot and steaming. Heat Exchange Espresso Machines: These machines also have only one boiler; however the boiler has a pipe that goes through it and that is the heat exchanger. The water in the boiler is kept at steaming temperature while the heat exchanger is put into use when brewing. The cold water from the reservoir is pushed through the heat exchanger and is heated by the steam in the boiler. It then moves to the group head to go through the coffee grounds. With the heat exchanger you can brew and steam simultaneously! Dual Boiler Espresso Machines: Double boiler espresso machines have two separate boilers, one for steaming and one for brewing. Here too you can steam and brew at the same time. These machines provide the most stable temperatures for both brewing and fast steaming but are much more expensive. Some features to look out for in pump-driven espresso machines that may affect your purchase:
Pre-infusion or Pre-brewing Cycle: The grounds are wet briefly just before the primary brewing cycle. This brings out the best flavors of your coffee. Cup Warmer: Warming your cups prior to brewing is essential to maintaining the coffee temperature of your shot. Cold cups can take away some of the heat of your shot. Thus many machines may have either an active cup warmer which is heated electronically (which is obviously the best option) or a passive cup warmer which is heated by the heat that is leftover from the boiler. Milk Frothing: Most espresso machines include a steam wand to froth and steam your milk for a cappuccino or latte. Froth-assisted wands such as Pannarello wands or turbo frothers are steam wands that have holes that are designed to intake air and mix it with steam to create froth. These wands make it easy for even a newbie to create creamy cappuccinos and lattes.
These are usually found on entry level espresso machines that don’t have enough steaming power and compensate with the froth-assistor. Commercial wands can produce the ideal silky micro-foam since the machine provides the necessary steam power needed to exit from the holes on the metal tip of the wand. Some super automatics include an automatic milk frothing system in which steam power from the machine draws milk from a container, froths it with the steam and air, and then dispenses it into your mug. Simple and convenient! Solenoid Valve: The 3-way solenoid valve means that after brewing, barely any water is left in the portafilter, so the puck is solid and dry and can be discarded with one knock. No soupy mess! It releases the pressure that builds up during the brewing process and filters the water left over in the group to the drip tray. Vibrating vs. Rotary Pump: Rotary pumps are quieter as long as they are receiving enough water and they work best with plumbed in machines. They are also consistent since they deliver the full water pressure when a button is pressed. They are expensive to replace but they last much longer. Rotary pumps are best suited for high-volume espresso extraction and are mostly found in commercial-grade espresso machines. Vibrating pumps are mostly used for machines with reservoirs and although noisier they are cheaper and easier to replace. They can also cope without constant need for pressurized water. They are not as consistent as the rotary pumps and start off with little water pressure (however some people see this as a pre-infusion). Vibration pumps can handle up to 50 extractions per day and are mostly found in semi-commercial espresso machines. Portafilter Types:
A portafilter attaches to the group head of the semi-automatic or manual espresso machine. It carries the coffee grounds which you tamp into a small round disc. There are different types of portafilters and they may make a difference to you when choosing an espresso machine. The Commercial Portafilters are generally 58mm and weigh around a pound or more. They are usually chrome plated and carry well under high heat and pressure. They do have a learning curve as the quality of the shot will depend greatly on the grind and tamp of the coffee. 30 pounds of pressure is needed to tamp properly! Once done properly however, it can create an excellent espresso with a most beautiful crema. A Pressurized Portafilter makes it easy for beginners to brew espresso. It does not depend as much on the grind and tamp of the operator. It provides the pressure needed for brewing and does all the work for you. They do not allow water to pass through until the correct pressure is reached. All you need to do is tamp the coffee lightly. However Pressurized Portafilters will not create the so called real crema or the perfect tasting espresso and you don’t have the same control over your shot as with the commercial style portafilters. They are also made of aluminum and plastic and are not as durable as the commercial portafilters. Pod portafilters accept coffee pods thus eliminating mess and hassle. Coffee pods are little filter packs that
have pre-measured single portions of ground and tamped coffee in them already. ESE (Easy Serving Espresso) pods follow certain guidelines that are an industry standard that many manufacturers and roasters have joined. This gives consumers a much bigger selection and many machines are designed with the capability of accepting them. Capsule Based Machines: offer reliability and ease-of-use. If you don’t have an interest in becoming a home barista but want a decent coffee drink every morning then this type of espresso machine is for you. To prepare your drink all you need to do is insert the capsule of choice (which has premeasured ground and tamped coffee in it), then start the machine and presto- your coffee is ready. Clean-up is simple- all you need to do is discard of the used capsule or cartridge. A downside is that there may not be as much variety as ESE pods would give you, because the machines generally only take a specific brand of capsules. Some Pump-driven machines: Super Automatic Machines These machines do all the work with the simple press of a button. No grinding, tamping, or steaming. The machine does everything automatically. It will grind the beans, tamp them, boil the water and push it through the beans at just the right pressure. It even ejects the spent coffee grounds or puck into an internal waste box. They will also steam and froth for you, creating delicious cappuccinos and lattes. Although some will say that super autos do not provide as good tasting espresso, it still makes a quality drink, removes guesswork and is convenience at its best! All you need to do is provide good quality coffee beans. So if you are really busy, have the extra money to spend on your coffee habit, but want a good quality espresso in the comfort of your own home, then super automatic is the way to go! Fully Automatic Machines The pump in these machines can be programmed to preset the water volume that will be released each time you brew. So when you press a button to brew your shot, the machine will release the preset volume of water and will stop at its preprogrammed amount. Since these machines also come with other capabilities they are usually more expensive and are not standard in the home. Functions they normally include are a few programmable drink sizes as well as the ability to use the machine as a semi automatic. Semi-Automatic Machines The main difference between this and a Fully Automatic is that you control the amount of water released by pressing a switch. So if you see that the shot is flowing quickly you may want to stop the pump earlier or if the water flow is slow but good you can lengthen the time of the shot. Semi automatics also include a steam wand for frothing and steaming milk. It may take some mastering but once you’ve figured it out your cappuccino will look and taste amazing with a thick layer of micro-foam. These machines are the most popular for domestic usage. They have a small learning curve and require little practice beyond following manual instructions. Getting the right grind and tamp is a bit of an art but gives you additional control to the quality of your shot. You also need to get a good grinder and fresh coffee beans to ensure a consistently good shot. Piston-Driven Machine: Manual Machines This is for the true coffee lover who cares about the art of preparing an excellent shot. The user has to manually ‘pull’ a shot using adequate pressure to press the hot water through the coffee grounds. By pressing a lever you either apply pressure directly to the water which pushes through the grounds or you compress a spring which pushes the water through the coffee. The learning curve is high but the satisfaction of pulling a good shot is even bigger. They are also aesthetically pleasing and make a beautiful display piece. |
