Izzo Alex Duetto V3 Review

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#1: Post by HB »

The popularity of the E61 group among home barista's is well established; Izzo's rendition of the group brings lots of other popular features like electronically controlled brew temperature (often called a "PID"), rotary pump, and the flexibility to switch between water drawn from an inboard reservoir or directly plumbed. This review will summarize the Duetto's brew temperature consistency, steaming performance, and offer tips on producing the best espresso.

Izzo Alex Duetto evaluation model courtesy of Prima Coffee

UPDATE: Read the final writeup Izzo Alex Duetto V3 Review.
Dan Kehn

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HB (original poster)

#2: Post by HB (original poster) »

The E61 group has a well-earned reputation for being "forgiving" of minor barista errors. Water is evenly diffused over the surface of the puck prior to pressurization; this initial wetting allows the puck to expand and potentially close small fissures. The automated preinfusion also helps reduce channeling by slowing the brew pressure ramp (for those who are curious, Internals of an E61 Brew Head and Pressure profiles, preinfusion and the forgiveness factor elaborate on this point).

Although it isn't cited in the E61 patent application as an innovation, the implementations have always featured a thermosyphon that circulates heated water to/from the boiler, enabling the grouphead to idle nearer to brew temperature. Many of the E61 espresso machines on the market use a heat exchanger to deliver brew water; the article HX Love explains how the barista flushes water through the group to fine-tune the brew temperature. But the Izzo Alex Duetto, as the name suggests, has two boilers, one dedicated to steaming, the other to brewing. It still relies on a thermosyphon to keep the grouphead toasty, but the flush routine is simplified compared to an E61/heat exchanger combination.
Dan Kehn

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HB (original poster)

#3: Post by HB (original poster) »

Modeled after the WBC Procedure for Measurement of Brewing Water Temperature, this weekend I used a Scace II thermofilter to map out the thermal characteristics of the Duetto when idle, under load, and with/without the steam boiler preheating incoming brew water. The timing intervals I tested are idle for 30+ minutes, then measuring the temperature with 30 seconds between pulls, 90 seconds between pulls, 3 minutes between pulls, 6 minutes between pulls, and 10 minutes between pulls. The peak brew temperature is measured at the 20 second mark.

With a setpoint of 200°F, the idle no-flush temperature was 197.6°F. Not surprisingly, this indicates that the group idles cooler than the target brew temperature, as I've measured on other E61 groups. The next measurement 30 seconds later was nearly spot on at 199.4°F. With closely spaced intervals of 30 seconds representing back-to-back shots, the temperature ticked up one-half degree under the influence of the hotter heat exchanger temperature water. Spreading out the interval between test extractions showed the group returned to its idle state between 6 minutes (min) and 10 minutes (max). All-and-all, a very good showing for a semi-commercial espresso machine.

The Izzo Alex Duetto has a separate switch to disable the steam boiler. This is handy for espresso purists who only occasionally need steam for lattes and cappuccinos. But the lack of preheating incoming water does impact the brew temperature stability slightly. The initial idle temperature was quite cooler without the benefit of the preheated water, measuring 196.7°F. The temperature at 30 second intervals dropped off almost a full degree, averaging 198.6°F. The most notable difference was the brew temperature under load; closely spaced extractions were less stable, presumably because the electronic temperature controller (PID) would overcompensate and thus overshoot the target temperature. Even so, if your pace is no more than one espresso every 90 seconds, powering off the steam boiler had little impact on temperature stability.

In a nutshell, for best temperature stability on the Duetto, do a very short flush if it's been idle for more than 3 minutes and allow 30 seconds for the group to re-stabilize before starting the extraction (e.g., flush before dosing/tamping). If it's been idle for more than 6 minutes, do a longer flush instead (e.g., enough to prewarm an espresso cup). It's really that simple to nail the brew temperature within one degree every time.
Dan Kehn

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HB (original poster)

#4: Post by HB (original poster) »

Since springtime of this year, Phillip Marquis and I have been making the video series Newbie Introduction to Espresso. The subjects it covers range from appreciating espresso to barista mechanics to problem diagnosis. In the latest video of the series, we discussed the capabilities, capacity, and consistency of the difference classes of espresso equipment. I also covered some of the points raised in the question and answers format of the site's How to choose an espresso machine and grinder at the "right" price recommendations. Finally, with six months of experience as a home barista, Phillip shared his decision process and offers his own advice for buyers in similar circumstances:
To practice what he's learned at home, over the course of several months, Phillip borrowed the Gaggia New Baby, Breville Dual Boiler, and Izzo Alex Duetto. Now that he's had ample time to evaluate them, he offers his thoughts on the strengths and weaknesses of each and where he stands so far in his buying decision.
Phillip Marquis wrote:It's been 6-8 months now since I've been introduced to the world of home espresso, and I've definitely graduated from the belief that a Starbucks latte was the best of the best. Don't get me wrong, I do still very much enjoy Starbucks lattes when I'm out and about, but I realize that since I've had the proper training, I can produce a latte that far surpasses Starbucks. Not to toot my own horn, because I still need a lot of practice.

I consider myself very lucky have not only had the hands on training, but to get to bring three different machines home and see how they work for me. I know that all new home baristas will have their own experience, but I want to share my own with three different machines: The Breville Dual Boiler, Gaggia New Baby, and the Izzo Alex Duetto.

Being that there are a billion different categories that I could compare these machines, I'm going to keep it "newbie" simple. Meaning, the variables that are important to me. 1) Look and feel. 2) Ease of use to produce good tasting espresso. 3) Which one I will probably purchase when factoring everything, including cost.

Look and feel to me has to do with weight, materials used, its aesthetic appearance, and just overall feel. The best would definitely be the Duetto. Although I don't enjoy moving it around (it weighs a ton for such a small machine), its weight tells me that there is a lot going on in there. It's surrounded by bulletproof steel, and although I wouldn't try it, I could probably run it over by a truck and it just have a few scratches on it. The levers are solid, and I could probably put about 100lbs of pressure on the portafilter before the machine would shift. The Breville was also great, very sturdy and solid with quality parts. The main difference is that the shine of some of the plastic material told me that they wanted to cut costs somewhere, and that was where. The Gaggia on the other hand was the polar opposite. It seemed like just adding 15 grams of coffee in the portafilter might be enough to tip it over. I could see behind its faux metal plating and I couldn't get past the idea that I felt like I was using an appliance very similar to an easy bake oven.

Then there was ease of use... the Duetto took it again. Still trying to get a grasp on why, but when my grind is right, and I have fresh coffee, it just makes a perfect espresso every time. The steaming also is crazy. I could probably boil a quart of milk in about 45 seconds with that thing :D. The Breville was also impressive, especially for having two small boilers. If I had never used the Duetto, I wouldn't have known that the Breville's steaming capability was not the best you could get. The Breville also made things very easy for me, especially since it was the first machine I used. Again, on the other end of the spectrum, the Gaggia almost made me want to give up home espresso all together. I found myself making many more trips to Starbucks during that timeframe. Not only was it nearly impossible to get my espresso right, the steaming was feeble.

To sum it up, the only real comparison was between the Duetto and the Breville. But between the Duetto and Breville, it's a very close decision. The conservative side of me says that I don't need the Duetto when the Breville does such a fantastic job, really everything I need to have a great espresso machine. However, as we all know it's not always about just needs. Now that I've had the Duetto, I WANT it.
Thanks Phillip for your "newbie" perspective! Over the next couple of weeks, I'll finish the research phase of this review. Before wrapping up the review, I plan to compare and contrast the Duetto against an E61 / heat exchanger espresso machine, the ECM Technika IV. If I can arrange with Phillip, I would also like to make another video specifically dedicated to the "HX vs. dual boiler" debate.
Dan Kehn

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HB (original poster)

#5: Post by HB (original poster) »

As I mentioned in the La Marzocco GS/3 MP Review, once a month for the last few months, I've been serving espresso/cappuccinos at a local dealership's "cars & coffee" event. The employees and attendees really appreciate coffee better than the usual preground drip brewer fare and I get an opportunity to test the review equipment under a higher than typical production pace. The Duetto had its outing this past weekend.

Thanks to absolutely beautiful fall weather, the turnout was larger than previous months during the summer. Over the course of two hours, I served approximately 50 people, going through 2-1/2 pounds of coffee and two gallons of milk. I had the Duetto setup to use the reservoir, which was somewhat inconvenient as it needed refilling several times. Next time, I would consider bringing a Flojet and a 5 gallon jug. Note that even though the Duetto's driptray looks deep, most of the depth is actually a faux front concealing a collection cup directly beneath the driptray for draining if the machine was plumbed into the house's wastewater system. Subsequently, the Duetto's shallow driptray holds little water and needed emptying several times over the course of two hours.

Water logistics aside, the Duetto performed admirably under load. Its steaming time is at least 2x greater than commercial espresso machine standards, but still fast enough that I dealt with orders five deep without any complaints about the wait time (true to typical cafe protocol in the US, I wrote a name and drink on a cup for each order, then called out the attendee's name when it was ready). The only noticeable performance crunch for the Duetto was when making Americanos: When I drew out the 6-7 ounces of water via the water tap, the steam boiler pressure cratered after the refill kicked in. The Duetto struggled to keep up if I wanted to make several Americanos in a row; this happened a few times when I suggested Americanos as a substitute for regular coffee drinkers.

Tip for Americano lovers: Use a kettle to heat water to the correct serving temperature (e.g., 30 seconds off boil) and then add to espresso. If you want to use water from the steam boiler, first draw it into a cup and let it cool. Don't add it directly or the excessively hot water from the steam boiler may turn the crema an unsightly pale color. For other suggestions, see threads like Americano Perfectly Temped Water.
Dan Kehn

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HB (original poster)

#6: Post by HB (original poster) »

HB wrote:Before wrapping up the review, I plan to compare and contrast the Duetto against an E61 / heat exchanger espresso machine, the ECM Technika IV. If I can arrange with Phillip, I would also like to make another video specifically dedicated to the "HX vs. dual boiler" debate.
Below is the promised video, Heat Exchanger vs. Double Boiler Espresso Machines:
Dan Kehn

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HB (original poster)

#7: Post by HB (original poster) »

Before wrapping up this review, last Friday we held an informal shootout of the Izzo Alex Duetto against the La Marzocco Linea PB. Counter Culture Coffee in Durham hosted us and supplied the Apollo single origin espresso as test coffee.

Simple level-cut dosing technique (no settling of grounds, no grooming)

Before the test began, I confirmed the temperature and brew pressures were equal. The coffee was dialed in on the same Nuova Simonelli Mythos grinder and the same dose; the pour times were within 3 seconds of each other at approximately 25 seconds.

Preparing to cut off when pour starts blonding

Each participant was served two demitasses at the same time. They were not told which drink was from which espresso machine; they were asked to hold their comments until the end of each round.

Double espresso - Izzo Alex Duetto V3

Double espresso - La Marzocco Linea PB

Izzo Alex Duetto (left) vs. La Marzocco Linea PB (right)

In some rounds, drinks were mixed to eliminate crema visual differences and combine layers

After the session ended, I asked each participant to send their thoughts on how the two espressos compared:
Walt wrote:My first impression tasting both espressos blind was how close they were in the favor profile. Apollo was a good choice in that it can vary greatly depending on the parameters used and can be tricky to get all of the complexity out of the coffee.

The espresso from the Duetto was very good but the fruit didn't hit me and the finish was dry compare to the LM which was juicy and had a bit more body. It took a couple of tastes aerating the espresso in my mouth to pick up on the differences. Both did an excellent job with the Apollo and though I preferred the LM, they were so close that the Duetto was the real winner from a price performance perspective.
Nathan wrote:The shots from both machines seemed pretty similar, in general, but one set [from the Duetto] consistently had a dry, lingering aftertaste and was just a little flatter in terms of overall depth.
Tim wrote:LM shot-- Fuller body and sweetness, high notes and low notes. Better sweetness and citrus.
Duetto shot -- Nice but slightly less sweet, "brassy", and lacking a little body and fullness.
Phillip wrote:It was quite enlightening that I could actually taste that much of a difference having a very novice palate. Both were great, but the Duetto had a smoother taste to it, while the La Marzocco had more of a spike of flavor that was noticeably different.
Kurt wrote:While I am only a few months into this espresso thing, what I learned today is that if you use the La Marzocco as a benchmark for producing a top quality shot, then the Izzo gets you 90-95% of the way. The amount you have to spend to get further up on the quality curve begins to get rather step on a price versus quality graph.
Nick wrote:Overall, the two tasted remarkably similar, though there were some subtle differences that I noticed. The espresso from the LM had slightly more pronounced/clear flavor notes with chocolate and fruit. The Duetto's shot had these flavors too, but they were more subdued, and this shot had a bit of a bite at the back end that I initially described as "sour/tart", though I felt that Tim's "brassy/metallic" was a more accurate description of what I was tasting.
Walt and I were the last to sample the espressos; I agreed with other attendees that the two were very close in flavor profile, though the La Marzocco held an edge on clarity. I described this separation of flavor as two chocolate bars, both containing nuts, but the nuts in one are finely ground and the other coarsely ground. To continue the analogy, the overall flavor profiles of the two chocolates are very similar, but the taste experience of "nuttiness" is noticeably different. Some might describe the more subtlety defined taste of the finely ground nuts in chocolate as "smooth" and the coarsely ground nuts as "sharp". Both espresso were very good, but not identical.

We were getting ready to clean up and Tim walked in at the last minute. Without having heard any previous discussion, he echoed many of the same comments as earlier participants. In my mind, that demonstrated that our results were consistent and reproducible. In the finally tally, the Linea PB beat the Duetto 6-1, though it's worth noting again that all the participants agreed the spread was surprisingly narrow.

Thanks gentlemen for your comments! And thanks again to Counter Culture Coffee for hosting our comparison test and supplying coffee. This concludes the research phase of this review. Comments or questions are welcome; the final review will be published soon.

In closing, below are the participants that I was able to photograph:

Phillip of Newbie Introduction to Espresso fame


Nathan (in the background, Walt [l] and Dan [r])


Oh my, it's good to have a dishwasher!
Dan Kehn

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#8: Post by TomC »

A very well done review. I think it will help those looking to up their game, find that great espresso can be had very consistently with the Duetto, without much fuss. And to cup relatively well against an expensive commercial rig like the LM, it becomes a decent value.
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#9: Post by sonnyhad »

Very nice, now if one could find a discount on one, that would be cool!