Thanks for sharing your experience. A couple comments sent me to find your experiment but I could only find it German and the translation left me with more questions than answers. In the end, I respect that you approached this in a more scientific way, and it absolutely makes sense that the thermoblock would struggle to heat water coming through it at such a rapid pace. Yet, my concerns about it’s thermal stability still stand though my approach was admittedly less than ideal. The difficulties the machine had at extracting lighter roasts and larger doses lead me down this path, and I chose to show this test I conducted instead of my TDS results of the reduced shot temperatures I was experiencing in the cup for the sake of brevity and visualization. That said, I do have difficulty believing that in the cases of a proper boiler machine, dual or not, that the thermoblock will be more consistent in temperature flash heating flowing water than a container full of water set to a certain temperature. But as a show of good faith, I will pin your comment and let those who watch the video and read your comment decide for themselves how to proceed.

​​@@Sprometheus I think at this point you are just trying to justify the lack of a more accurate way to measure the temperature stability without a better way than just a kitchen thermometer and portafilter without any resistance, to many subscribers already explained to you why this way it's certainly not accurate and you just said it's the only you have to made the measure and you can't have a Scace or something similar to do a right approach for this. But if you have YT channel and make reviews of espresso machines and other stuff how you can't justify having some like the Scace to have the right tool for your reviews? I think it's an investment that will help you and will increase your views/monetization with more accurate reviews because at the end we saw your channel for your honest opinion but when it's made in the right way because of course your opinion will influence future buyers

@@Sprometheus Thanks for pinning, Sprometheus. Technically speaking, what Ascaso uses is a thermocoil. Decent also uses a thermocoil. Some other modern machines are using Thick Film Heaters with even less thermal mass. I think the most important thing is good and fast sensor technology to make good use of these technologies. If not, you are absolutely right, and the temperature will be super off.

@@Sprometheus I feel kind of bummed out for the engineers at Ascaso that you put up a video asserting their machine has unstable temps including a clip that suggests it lost 10 degrees in 10 seconds under normal usage. That feels totally unfair if they aren't even allowed to point out a flaw in your methodology that ends up turning into what basically amounts to a huge smear that effectively makes the machine a no-go with anyone who trusts you and doesn't like Starbucks espresso. And when called out, with zero empirical evidence, you just assert that your conclusion stands because you (subjectively) thought shots were sour and there are some undisclosed TDS results hanging around somewhere (which technically couldn't be pinned on a temperature decrease conclusively anyhow)? If you thought sticking a thermometer in a gusher was a good metric of something relevant to the machine's ability to make espresso, why would we assume that anything else you did was better thought out? (And I'm absolutely confused as to why you thought a test that you told others would be "quick to point out" the flaw with, is a good way to demonstrate a "problem" that you only provided anecdotal evidence of otherwise. If it were me, I'd just admit my measurements were flawed to the point of being completely irrelevant and edit the video to add something in recognition of that fact so that I wouldn't be continuing to mislead consumers considering this machine (or the souped-up variants of it that have the same brew thermoblock). But maybe that's just me thinking the people who build these things and get them to market deserve to have their work accurately assessed when put in front of 100,000+ people, and that the person doing the assessment needs to be accountable for the claims they make--especially when the company is taking a risk by not sticking with the boilers that so much of the espresso community believes is mandatory for making good espresso.

Also not mentioned in the video is the PID offset of the machine. Various users have done experiments and recommended anywhere between a 4-8 degree offset. If your offset was set to 0 (default for the machine as shipped), you will definitely be underextracting light roasts, which might have led to the sour shots you mention. Once I discovered this and set the offset (in my case 7 deg), my shot quality and consistency increased dramatically.

Fully agree. I wonder if the Duo has the same downside.

I had such a hard time finding reviews by 3rd party users and I ended up needing to read Reddit posts for reviews and ended up purchasing the Duo because I liked how it looked and it seemed good enough.

@@camperista honestly, we had discussed them sending the Duo after this video, but based on the issues with the UNO I am very sure the main issue persists.

​@@Sprometheusmaybe you could jump to the Baby T in order to test their higher end designs.

So just so I know, which reviews are paid for by Ascaso.

Agree with all of the above, especially with the unfortunate volumetric flow meter placement (before the OPV). However, I have had much more stable automatic shots in combination with pre-infusion (e.g. setting 3-5). It takes away some of the variance produced by the operator

Is true about the portafilter being cold when starting the machine, but if you are in a hurry, you can run an empty double shot to warm it up, leaving the hot water inside the basket until use. That speeds up the process. And if you use a bottomless portafilter, the only thing that needs to be warmed up is the basket.

@@matiasnruffa yeah, that's absolutely true of course. I try to avoid that usually because I'm using bottled water in the machine and want to waste as little as possible. in my morning routine I'll now use the water I boil for tea to preheat my cups and the portalfilter before use

Driving a Steel Duo v1 for a month and have noticed much of the same you mentioned. Temp has been a non issue for my med. roast 18g, I too manually extract with a scale, yet I have had very good results with my milk, using 6 or 8oz. The only (tiny) issue I have is, I wish the steam was more 'on demand', like the Profitec 600 pro I use at work (obviously the perks of a dual boiler).

@@d.a.2426agree the placement is not ideal, but if I’m understanding correctly, if the OPV is never activated, the point is moot. And IMHO the OPV should rarely if ever be activated because it shouldn’t be reduced from around 11 bar. Shots should be adjusted with grind, temp and puck prep, not OPV. if you simply lower the OPV to reduce pressure in an attempt to improve your shot, that won’t work. You’ll still get bad shots and if the OPV activates, you’re def getting an interrupted and bad shot.

@@Big-Professor-6436 Yes, putting a thermometer into the spout of the portafilter and running water will not work for measuring temperature stability on most small boiler machines. I know it doesn't work on a Gaggia Classic for example. The thermoblock in the UNO seems to fall into the same category.

Maybe that’s the case. I didn’t look up reviews or tests on on this machine, but there was no other reason I could find it was failing to produce decent extractions on light roasts as well as not so hot shots after the fact. Sure testing in this way isn’t the best, I’ll admit that. But it’s what I had on hand, and spending $500 on a scace wasn’t an option for a one-off test. So this got me the results I felt were reasonable. And considering how stable the GS3 was it seems the most plausible explanation. I have to say I’d be shocked if flash heating water in a thermoblock would be more consistent than a boiler full set to a certain temp. If that was the case you’d think thermoblocks would be far more common because of the efficiency and power savings.

@@Sprometheus Was the temperature offset on your machine configured by the seller? The PID on all ascasos has some offset which varies from machine to machine (can be up to +/- 6ºC) and it has to be configured using a Scace. Maybe you were brewing much colder or hotter than you typically are?

@@Sprometheus A DE1 is generally temperature stable with effectively a glorified thermoblock. So are sufficiently large HX machines* (which also don't have a brew boiler). This isn't a defence of the Acasco implementation, just the possibility of effective themoblocks.

@@Sprometheus thx for the long reply. I think thermoblocks do have the potential (if well made). I think the reason they aren’t that popular (yet) is because most companies don’t want to innovate that much and having a boiler seems to be a given for most people. It’s a somewhat safe bet. Innovations on the (home) espresso machine market are slow. I think in fact there might be more thermoblocks and alternative heating ways coming. Also nowadays small boilers are also very efficient and quick.

I think ascaso baby T plus has what you say but it's very expensive

@@sebaba001 Very true. $4000 is way too expensive for me :(

That’s why you shouldn’t decrease the OPV to try to fix your shots. Leave it high enough that it doesn’t activate except in the event of a bad malfunction.

I wonder why the Duo wasn't mentioned at all in the video.

I do this exactly. 2.5 ratio at 98c. I'm finally able to have third wave light roast coffee with a machine that only has a 3 min startup. 5 min if I want the basket hot too.

I have a Bezzera with volumetric presets and I never use it. The shots vary for many reasons I suppose so I find it just as easy to look at the second hand on my wall clock and the volume flow.

the volume varies if OPV opens so if you will use a bit coarser grinding, it can be prevented or a bit higher OPV setting extraction pressure is not that critical variable

^this. He had the machine programmed incorrectly for pre infusion.

It's the way he measured it. The flow rate is too high without puck pressure for the thermoblock to heat up the water and holding the sensor to the spout will always be inaccurate.

I just looked this up on their blog and translated it and couldn’t find any information on stability behind them just saying it was stable. Is this info in video or a blog post?

I mean many folks are quick to point that test out, and I knew they would. The fact of the matter is, Im aware it’s beyond what a normal water debit is for espresso, it was to show the discrepancy between a boiler stability and the thermoblock. Im happy with the results, believe they show the issue that held back it’s ability to brew lighter roasts and larger doses though it may be exaggerated. In the end, take it or leave it.

Thanks for your response. I believe your testing/tasting results. I was just a little surprised because I usually heard that temperature stability was an important selling point for this machine.

Glad you enjoy it. It definitely is power efficient!

I’m not an expert on the technical side either, but running a YT channel on a shoestring budget means I make do with what I have. A scace is $500 plus dollars and isn’t a good investment for the rare occasion it seems useful for a channel that mainly focuses on brewing not the technical side. Sure, people can doubt the accuracy or results, but I think it’s clear that a boiler filled with water at a set temp will always be more stable than flash heating, that’s the point I was trying to make, and the visual I was capable of providing.

I think we planned on a DUO as well, so it’s likely you’ll see one here.

great! @@Sprometheus

I mean these issues are due to a declining temp, particularly when pulling shots in more contemporary shot styles. Sure, turbo shots and what not it will perform better, but to assume that everyone buying a machine at this price point is planning on pulling highly controlled shots that are popular on Home Barista forums or Reddit isn’t a common reality. If that’s the case, hand press/lever machines would be the peak of performance for those styles anyway. I think a big trap we fall into as coffee hobbyists/professionals is assuming everyone is on the same page, and with reviews, particularly on more moderately priced, prosumer options I think approaching it like this makes the most sense for the widest audience.

Thanks buddy. This comment along with the other comments have helped me make up my mind. Will be looking at getting something else. Too bad ut looks so good 😢

with correctly prepared puck/correctly set OPV (these 2 variables correlate) it is impossible, the power is enough to deliver up to 3.6 ml/s (2 standard espressos under 30 s) so the problem is flow too high, that means a) pressure too high (it is quite probable it was set to max at the factory, and that will be close to 12-15 bar) and/or b) puck resistance too low (grinding too coarse) by the way, extraction of standard 30 g espresso should be around 30 s, so retaining that flow temperature is guaranted

Not being able to hide your disappointment with a wife’s gift is the worst. I completely empathize. 😂

For sure, I mean no complaints on the looks and the usability. Really it only falls short on that temp stability. I was pleasantly surprised with the steam power.

I understand your point here, and yes the flow rate is always going to be faster without the back pressure of a puck, but the issue still stands as relevant. For instance with my grinder and current workflow I rarely see extractions below 21% and with this machine I was barely scraping the low 18%’s with medium to light roasts on doses 17 and above. The only thing that was different about this machine than most of the others I’ve tried is the thermoblock, and the low tech way I choose to display the issue, though not realistic in flow rate, does show the problem. As well as the low peak of the machine hitting the mid 180s at the group with the machine set at 206. So the sum of all of the information I collected, i.e. low extractions, lower temp shots on longer pulls, sour extractions on light roasts, only can lead me to one place and that’s where the heat comes.

@@Sprometheus Thank you for your response, it's a very clear answer! It's honestly a joy to see how well you test the machines before posting a review. Your testing and review is much more valuable than my anecdotal experience with the machine (and most of the reviews online that are pretty much just that). Their prosumer model, the Baby T, uses a thermal loop around the steam boiler to preheat the water before entering the thermoblock. I wonder how that system would fare.

You’re welcome and thanks for watching and the detailed comment. I get you, and I think there’s definitely a place for this machine on the market, and the Duo as well. I’m glad I had a chance to give this one a go, and as you said the quirks and downsides here are not going to hit the same for everyone.

It’s interesting you mention this because from watching the pressure gauge it appears it would run for 5 seconds prior to building pressure. I even watched the group flow without a portafilter and it appears to just gently flow without much pressure prior to the 5 second mark.

Agree with @Levinator25 comment. You have to set the first digit as well, otherwise the pump will just run through at full pressure. Mine is pre-2022 model and before the software update the user could even set the pause only, with a fixed pre-infusion of 3 seconds

Good question. That was at its full flow, so that’s it’s flow rate, or at least the unit I had. I had to pull back on the GS3’s flow rate to match the output and time. So I do think it is definitely on the lower side. I do have an expectation that that through a shot the temp will drop, but in my experience boilers tend to perform better over every shot timeframe, but this one doesn’t drop rapidly immediately and I think that tends towards it performing better with shorter ratios and lower doses, and that was backed up by taste and refractometer.

I am struggling quite a while with consistent shots. Also tried to limit pressure around 9,5 - 10 bars against blind basket. What is your setting? Shots seem to get better now.

Just seeing your question. A few things to offer: First I lowered the pressure a great deal. It came from Ascaso Factory set at a very high 14 bars. I lowered it and pulled some very sweet shots from light roast single origin beans. Since then I have replaced the grinder with a Niche Zero. A change of grinders also means minute changes in how I pull shots, I am now gone back to going up slightly in bar pressure, with shooting for the 9 bar range, pulled at a temperature setting of 202 degrees F, and a Preinfusion of 5 seconds. @@andreas3120

You’re welcome! And thanks for stopping by, have a great weekend as well!

Thank you my friend!

Thank you, and that’s funny you mention it. I’ve got a GO headed my way.

@@Sprometheus ​I'd love to know what value the E1 setting (boiler offset, at least I think so) on your Go's PID is set to and if you find it to be accurate. Mine is set to 10º Celsius and I have yet to try and check the accuracy.

​@ezarowny interesting because on the Go Facebook page many say that is not an offset. Seems different advice on Reddit

I’ve only had a chance to use the Synchronika but it was a solid machine! Glad to hear guide happy!

The Duo is a fantastic machine

Sure, a food thermometer isn’t the best tool for measuring this. I used what I had on hand as I’ve never had an issue with light roast extractions before, and after some troubleshooting this was the test I tired to see what I expected was happening. It confirmed that, albeit low tech. A scace is about $500, and considering the infrequency I’d use it it’s not a good investment, so I guess I’ll end up with a “weird singular conclusion” that is fair, and I feel accurate based on my experience.

Thank you. So in my tests I would see the temp drop a little quicker at the spouts with coffee as that also absorbed some heat too. So it’s harder to track that and I don’t have an answer directly, but my assumption would be about halfway through, as once it hits it’s peak temp pretty early in the flow, it drops off at a pretty rapid rate.

Interesting, I wonder why they just didn’t squeeze an extra millimeter out of that to be in-line with all their other machines.

@@Sprometheus - Cost - 58mm grouphead is a lot more massive compared to 57mm.. Portafilter is also a smaller beyond that 1 mm - thinner walls and smaller portafilter wings. 58 mm uses E61 style portafilters so grouphead is a lot wider due to that.

@@Eradorius or maybe marketing? I mean you are surely right but the differences probably aren’t in fact because they already have established production lines for 58 mm and making a somewhat niche 57 mm isn’t that cheap either.

but that assumption is false

@@tulenik71 do you have one to know?

@@classicrockonly yes

@@tulenik71 and you’ll do 18-20g and 40-60g output shots, turbo or allongé shots too?

@@classicrockonly regarding turbo shot - read what wrote Kaffemacher below. It is really flow rate what can cause tempereture drop. Nothing else. If 90 ml in 25 s is OK, turbo should be still OK. Allongé is approx. 100 ml in 40 s, so it is also OK. By the way, do you know basic thermodynamics? Because it is all about that. If you suppose physics (or chemical engineering, this is simple "flow" reactor - not even regular flow reactor, because one "reactant" - coffee - is not continuously delivered) can magically stop working here (based on the time of extraction?), you are completely wrong. The problem with long shots is outside of temperature regulation. The guy here completely botched methodology of temperature stability testing and you bought it, maybe you wanted some confirmation for your choice. That's psychology, and it is completely another chapter. (I am professor of chemistry and if I cannot find a difference by using HPLC, GC, MS, NMR or other analytical method, any "difference" coming from degustation is simply placebo... and placebo start to kick pretty hard at the moment you have working PID and flow or pressure (they correlate) control.)

Of course! Thanks for watching my friend, cheers!

Thank you. I have never felt the need to test the temperature stability in a machine before, and the costs of a scace $500+ just didn’t make sense to have on hand for the rare times id use it so I didn’t think it was worth the cost. It’s definitely a higher flow rate than any shot, but it was the easiest way to visualize the issue I was experiencing beyond me just saying it. In the end I know it’s not the ideal, but happy with the explanation of the issue and still consider it valid seeing how consistent a boiler was next to it with the same water debit.

⁠@@SprometheusThat makes sense. Having the GS3 definitely provides a gold standard to compare to. I actually have the Pro300, so I could try testing it in the same manner as you did the Duo to see if the smaller boiler performs any better.

@@Sprometheus So I tried to recreate this with the Pro300 (meat thermometer with no restriction). The Pro300 has a 330mL brew boiler, a faster water flow (150ml in about 17s), and the PID was set to 200F. It starts out at ~193F, hits 200F at 6s, 202F at 8s, 200F at 10s, 198F at 14s, 196F at 17s. So not the same stability you observed with the GS3, but possibly better (at full flow) than the Ascaso thermoblock.

I mean, if Emilee Bryant can get her kind of latte art out of a Breville Bambino, seems like nobody has an excuse.

@@Stan_sprinkle exactly!..the pitcher nor the steamer, makes a great latte artists..it’s the knowledge and experience that the barista has that it’s the most important thing to success

He recently had a blind taste test between gaggia and marzocco, and he preferred the gaggia shot... So the gaggia is only as bad as it quirks annoy you. Maybe the low steam power annoys you, or design flaws, or having to temp surf (if you didn't mod with PID), but if you aren't bothered then these expensive machines aren't necessary. Gaggia is like the cheapest machine that makes really good espresso, from then up it's mostly about comfort and control.

I low key like the Gaggia and really enjoyed it once it has a proper basket, and the lower pressure OPV spring.

That’s what I’m here for! Happy to provide it. Thanks for watching!

I’ve actually heard a lot of good things about that one, I should pick one up and give it a go.

Yeah, those are from www.odakahome.com

Always taking donations for one, $500+ for a single tool to do a single test I’ve never felt the need to do before isn’t high on my list.

Fair enough, it seems like no one has done it in the steel series

Absolutely, consistency definitely suffers, but I will say the steam on this one was pretty surprising. I didn’t expect much but it walks all over the Gaggia, but that is half the price haha.

"ages ago" is the key people are often disappointed by "slow" heating of boiler machines, yet they will buy boilers again and again there is an easy way of getting rid of second boiler, by involving thermo block for steam formation or heat exchanger, still common people will buy dual boilers because it is cool they even will never steam the milk alongside extraction, but having dual boiler is a status symbol in fact, thermo blocks are perfectly capable of delivering constant temperature, perfectly repeatable - and if you are - as majority of people here - steaming during extraction, one thermoblock is good enough and of course, thermoblocks are significantly more power efficient (don't really calculated this, but price difference can be paid off pretty quickly) mental rigidity is a real problem here - most people think about TB machines in the context of capsule machines (at the moment, I have a "hybrid" - single boiler with TB for steaming, but considering pure TB for an upgrade) TB vs boiler price difference is probably close to none, but if there is greater demand for boilers, unit price is, at the end, a bit lower Ascaso has absolutely no reason to produce boilers - there are myriads of boiler machine producers.

of course it is you forgot uninterrupted steam/hot water delivery and possibility to set up OPV without PID you can forget about light roasts (a BIG problem for GCP)

measurement methodology here is totally flawed, in fact Uno is pretty good in holding the temperature

you don't get a preinfusion nor any temperature control, no OPV setting, no hot water delivery, small boiler and that's all it is a bit too expensive but it is energy efficient, so those money will pay back

It's more expensive by $25 which isn't a lot. What do you mean by way more bang for the buck? Aren't they practically the same minus the heating types meaning Dual Thermoblock (Ascaso) vs Dual Boiler?

Indeed it is!

Personally I don’t believe in the “dead shot” program, actually did a relatively popular video about they awhile back, but that workflow can definitely deter folks. And yeah, the price point can be a bit stiff considering the competition in that range.

If nothing else, the shot is colder after two minutes of sitting there.

Curious about this too

Little digging looks to be the “pro” version of the search pean/kc200 scale. I have the non pro…they’re alright. This one is just a metal version of the standard one it looks like

@@joey.frank1 Thanks!

Why? It’s like a two year old short? What needs to be discussed? I didn’t use a tamper, I pulled a shot and somehow it got 12 million views.

Yeah that’s an interesting point, I mean, it’s definitely feature dense, but the thermoblock is more or less a budget friendly option, and it seems like most of the options with it are under $1k.

Wait until you find out what the decent espresso machine uses 😅

Hahaha I thought I was picky!

It definitely excels in aesthetics, but I think it performs pretty well within its somewhat strict design guidelines.