Some machines use a single boiler kept at steaming temperature, but water for brewing is passed through a heat exchanger, taking some heat from the steam without rising to the same temperature. Although the water for brewing remains at a lower range than that required for steaming milk, it is still too hot for proper coffee extraction without first cooling; thus this type of machine requires a cooling flush of 4–6 seconds prior to the first espresso pull. Once the machine is dialed into the proper temperature, as many shots can be pulled as required without refreshing. However, if the user leaves the machine idle again for some period, the flushing process will need to be repeated. The HX variety is found in many mid-range machines and many users install thermometers to assist them is dialing in correct temperatures. There is some controversy as to the temperature stability of the brewing water, since it is indirectly converted from steaming temperature to brewing temperature, rather than kept at a brewing temperature.
In the semi-automatic machine, water pressure and temperature must be stable and consistent, and according to our expert, the pressure shouldn't be too high. Typically, coffee is brewed at a pressure of about 10 bars, and an ideal water temperature is around 195 degrees. Generally, the more expensive the machine, the better the equipment inside that regulates these two factors. High-quality machines tend to have a mechanism called a PID, or proportional-integral-derivative, controller. The PID's function is to maintain constant water temperature with extreme accuracy, down to the degree. Two central problems plaguing inexpensive espresso machines is that they lack a PID, meaning the temperature of the brewing water can fluctuate up and down and yield inconsistent results. Inexpensive machines often advertise that they have 15 or 20 bars of pressure as a selling point. But, higher pressure is not the priority, and too much pressure can actually lead to over-extraction and bitterness in your espresso shot. Therefore, we looked for a machine with good temperature and pressure control.
"If I could give this more than 5 stars I would. I love espresso drinks from coffee shops, I used to drink just regular coffee but when I quit smoking the taste changed just enough that I didn't like it anymore. Mexican mochas on the other hand I still found palatable. But they're about 5 bucks a pop at my local coffee shop. I also didn't want to spend 150$+ on an espresso machine, they seem prone to breaking and judging by the reviews never really work right. So I settled on this, figuring I would try it and if it didn't make what I wanted I'd only be out about 30 bucks. It makes delicious coffee. Put some full city roast in their and fire it up and what comes out is espresso. From my readings I've gathered that its not actually espresso, as the Moka pot doesn't make enough pressure for it to be real espresso. But its playing the part convincingly, I can't tell the difference between what comes out of this and a shot of espresso. Its paid for itself a dozen times over at this point. Absolutely one of the best purchases I've ever made. I couldn't be happier."
If you're highly particular about how your coffee tastes, you'll want the Behmor Brazen Plus. It was the only drip machine we tested that brewed at the optimal temperature to bring out the best flavor from coffee beans. Getting this perfect brew takes a little more time to set up than most coffee makers require— before starting, you have to calibrate it for the altitude in your area— but overall it's easy to use.
Semi-automatic machines are not quite as customizable as a manual machine, but they let you play with a lot: You can change the coarseness of the coffee you use, the amount of coffee you add, and how long you pull your shot. Expect a decent learning curve to figure things out, and know that you’ll also need some additional equipment, like a quality coffee grinder.
Espresso fans can let their imaginations run wild with an espresso maker from Sur La Table. Part ritual and part art, making the perfect espresso is a passion for many and we have the tools. Whether you enjoy the simplicity of a single-shot machine or you prefer fully featured espresso machines with all the bells and whistles, you’re sure to find exactly what you’re looking for. And since we carry brands like Breville, Jura and Nespresso, you know they’ll provide delicious coffee for years to come. When it’s time to make the perfect espresso, visit Sur La Table.
CR’s take: If you like the look of black stainless steel, you can add a hit of the trendy finish to your kitchen with the Bella Ultimate Elite Collection coffee maker. Appearance aside, this model brews a fresh pot in just 9 minutes and is graceful in action, earning strong ratings in our carafe handling tests. It offers programming, brew-strength control, a pause-and-serve feature, and auto-shutoff. Bella drip machines also received a Very Good rating for predicted reliability. At about $50, this affordable, attractive option won’t disappoint.