I have had the Mypressi for eleven months, so this is a combination first review and one year follow up.
I love this thing. Mypressi is an elegant balance of complexity and simplicity. I bought it, followed directions and made a good cup of espresso right away using La Minita dark roast and a Gaggia MDF grinder. The pressure profile is fixed and dependable from first shot to fifth. This means I am able to learn about espresso quality parameters by paying attention to grind fineness, grind amount, water temperature, and infusion duration. It is possible to comprehend the differential effects of varying these four parameters while the type of water and the type of roast are held constant. Mypressi is able to replicate the elegant and detailed flavor profiles of popular roasts that I have had as ‘exemplary’ experiences in good coffeehouses.
About the four parameters: I leave water temperature as hot as I can, since, even with prewarming, there will be a considerable heat sink effect from the metal of the device. I leave the top cap of the water reservoir on all of the time during usage and storage except when I am actively filling the reservoir. Therefore, I first turn the metal reservoir assembly upside down, place it in a cradle of a 1 cup measuring cup and fill it with boiling water. I pour boiling water over the shower head screen. There seems to be no reason to heat up the handle/ring assembly – the contact with the basket and water reservoir is not conductive enough to make a temperature difference. When the Mypressi is assembled with the filled basket, I attach the water reservoir, take off the top cap, completely fill the reservoir with boiling water, wait a few seconds, then pour all of it out by turning the unit upside down. There has been no problem of the tamped grounds dislodging. Then I fill the reservoir with the recommended amount of boiling water, close the cap with the cap indicator in the correct position to keep track of the cartridge use, and pull a shot. Even with all of this preparation, my digital thermometer records a water temperature in the reservoir before capping of 200 º F or below. Although this is a concern, sour shots have not been a problem. With some searching online, one can find a time/temperature graph for the Mypressi. It shows the water temperature to slowly decrease from slightly above 200 º F to slightly below at the point of extraction. It is unclear to me how this was achieved. Despite my misgivings, this unit is able to replicate the detailed spread of flavors obtained by a high-end espresso machine on quality roasts. For my part, I will not vary water temperature, but try to maintain the infusions as hot as possible. I have not investigated preinfusion. The shower head has a pressure flap assembly that prevents water from leaking onto the shot until the unit is pressurized. If one is interested in preinfusion, I suppose pulling the trigger for two seconds, then waiting for a preinfusion interval, then pulling a second time might serve that purpose. Perhaps I will experiment some day.
Most of my ‘dialing-in’ is with grind size adjusted to each roast. I tend to keep the duration and the volume of the shot constant. Perhaps I will experiment with these, too, some day. I use a ‘greedy’ grind amount, 19 grams plus or minus 1 gram. It was surprising to go back to the web site and read that the recommended infusion times range from 20 to 30 seconds. Having been influenced by good coffeehouses, I have been keeping my shots to 20 seconds, plus or minus 1 second. I have good results with this and it allows me to get 5 shots from one gas cartridge (more later). Standardizing your infusion time takes the guesswork out of how long a cartridge will last. However, some premium roasts such as Greenway Coffee’s ‘The Veldt’ espresso blend, may uniquely require longer infusions times, 30 seconds or longer.
The unit is quite tolerant of technique. I have had very few bad shots and these could be problem-solved easily since the operation is so straightforward. The crema and body vary from acceptable to very good; most are good. A high-end machine will do better, but not by much, in my opinion.
The straightforward and simple operation will allow the user to equate the quality of the shot with the quality of the grinder, in some cases. Just because you spend about $150 on this unit, that does not mean that you can get away with a comparably-priced grinder. This seemed to be the experience of the reviewer, Geoff Lecoq. In my experience, my Gaggia MDF was up to the task. I was dialing the grind at 5 for some roasts, 4 for others, and then there was a roast that required a grind of ‘4-1/2’, which I approximated by grinding at 5, then tamping super-hard; the performance of the Mypressi could reveal the difference of one step. Only one roast required a grind of 3. Now comes the confession. On the advice of David Buehrer of Greenway Coffee (for which I may not forgive him), I purchased a Compak K-10 WBC for around $1400.00. Needless to say, the taste of all of the Mypressi shots have become more expansive and clearer. The Mypressi is therefore a device that has the ability to discriminate the quality of the grind, including grinds from commercial quality units. (Buying a grinder that costs ten times the cost of the espresso machine may be an overreaction to Mark Prince’s advice in ‘How to Buy an Espresso Machine’ and has already earned me some scoffs but I am drinking premium shots every day and I never have to lug a 70 lb. machine to the shop for maintenance. Maybe some day...)
The shortcomings of the unit have been minimal to nonexistent. The plastic tamper fits well into the basket except that the tamper disk is thin; this allows the tamp to tilt and the puck to be compacted slightly more on one side than the other. This may occur despite rotating or nutating the tamp but an embossed line in the side of the basket makes the eveness of the puck easy to gauge. Sometimes I have to readjust a slant of the tamp in this regard. The second small disappointment was having only one standard filter basket. I needed a second basket in order to make good use of the preheated water reservoir in a timely manner for more shots. Therefore, I had to buy a second basket. Also, beware, the baskets are small and a basket weighted with grounds can easily find its way down the throat of the garbage disposal and disappear. Thirdly, I lost one small o ring but the unit comes with plenty of spare o rings. I dislike o rings but what espresso maker does not require o rings for operation?
The most common criticism about the unit is having to buy gas cartridges and keep track of the number of uses. As much as I would like to support the wonderful folks at Mypressi, I buy my cartridges from ultrapurewhip. Two boxes can be purchased at a discount and will last a number of months. I believe this arrangement to be more convenient than descaling boilers, replacing thermostats and taking a traditional machine in for annual preventive maintenance. I use a small square of double-sided foam tape stuck to the bottom of the cartridge to make up for the 1 mm difference in cartridge length between the isi and the Mypressi cartridges; I have had no problems with leaking gas, even when the unit has been unused for weeks during vacation. Of course these units can travel easily and go with me on vacation; I just use a Hario grinder and a small electric boiling kettle. The four-position water reservoir lid is designed to count the number of times the gas cartridge has been used; the unit is rated for four discharges but most folks report getting five. I routinely get 5 by using 20 second infusions. Those using longer infusions may only get 4 uses from a cartridge. The lid-counter requires more operator mindfulness than a manometer gauge, as has been suggested, but it is more elegant, less complex, and the operator has complete control over whether it malfunctions or not.
Another way to know how much gas is left is to weigh the handle. You have to have a CJ-4000 or other equivalent balance that is sensitive to 0.5 gram in order for this to work. Also, be sure to support the bulky handle assembly so that it rests on the center of the balance stage. The handle assembly must be dry. The handle without any of the attachments on it with a full isi cartridge in place weighs 512 +/- 0.5 gm. Each 20 second shot uses 1.0-1.5 gram of NO2, assessed over many measurements. Occasionally a shot will be associated with a 2.0 or 2.5 gm decrease in weight, but some of this may be operator error. Many measurements of the handle (dry) after one shot give a mean and sd of 510.5 +/- 0.5 gm. After two shots, 508.5 +/- 1.0 gm. After three shots 508 +/- 1.0 gm. After four shots, 506.5 +/- 1.0 gm. After five shots, 505.5 +/- 0.25 gm. The cartridges were very uniform, weighing 28.0 gram when full and 20.5 gram when empty. Each cartridge holds 7.5 grams of gas. In each series, there was a tiny puff of gas evident when the cartridge was removed except for two series that had only 19 seconds and 5 seconds of gas left for the fifth shot. You will have to standardize these measurements for your own unit but, then, if you lose track of your lid-indicator, you can always weigh your handle.
The baskets are a breeze to clean. The shower head and spout assembly are quickly cleaned and everything else need not be cleaned at all after use.
A final note: Mypressi customer service is accessible, quick, friendly and accommodating. I contacted them for a very small need that had nothing to do with any problem or troubleshooting. Suffice it to say that they have a generous nature and I hope that their good will is not taken for advantage.