As a new Duetto owner I've done very little so far in terms of milk, but I'm keenly aware that I have to learn how to steam all over again. Previously I was using a Salvatore 2l HX with an NS Oscar 4 hole .9mm tip and had become pretty good with pourable art microfoam (my POURING was not spectacular, but the microfoam was not the limitation there...)
Now I'm back to the starting gates. I happen to have the joystick valves and the 4x.9mm hole tip on it, if that makes any difference. But the main question I'm asking is if anyone knows of any peculiarities or tricks to share for the machine. A.K.A., what temp/pressure you keep the steam boiler, what angle direction you position the wand, (tilted up high, angled straight down, held in the center of the pitcher, held to the side of the pitcher, submerge half-way, submerge to the bottom, etc.) It takes a while to familiarize with how a new machine handles, so hopefully tips from those who've already learned it can speed up the process!
What I'm getting so far isn't half bad...there's a layer of slightly over-foaminess, but it's an "almost wet paint" top after an extended stretch...but it's not being mixed in well enough, the bottom is still too steamy, but if I submerge deeper I start getting the "screech of doom" indicating insufficient pressure for going that low (the tip's fault, no doubt.)
CrayonShinchan Senior Member Joined: 18 Mar 2011 Posts: 109 Location: San Francisco Bay Area Expertise: I love coffee
Espresso: Izzo Alex Duetto II Grinder: B. Maestro & Vario, Peugeot... Vac Pot: Cona D, Yama Drip: Chemex, V60, Kone,...
Posted Fri Oct 21, 2011, 10:34am Subject: Re: Microfoam techniques on Duetto?
I have the exact same setup as you (4 x .9mm with joystick) and I tend to have a similar experience as you described. Microfoam is a little too foamy. The stretch takes a bit longer than it should, but if you don't do it long enough, you don't get the proper texture. I'm thinking of trying out the 2 hole tip I have to see if it makes a difference.
FWIW, I have the steam temp at 255.
Let me know if you have made progress?
I'm almost certain that it's mostly just me (I'm new to this) as my friend was able to produce good microfoam and thus good latte art. I'm like 75% there and wondering if the remaining 25% is me or the machine or both.
CrayonShinchan Senior Member Joined: 18 Mar 2011 Posts: 109 Location: San Francisco Bay Area Expertise: I love coffee
Espresso: Izzo Alex Duetto II Grinder: B. Maestro & Vario, Peugeot... Vac Pot: Cona D, Yama Drip: Chemex, V60, Kone,...
Posted Sun Oct 23, 2011, 11:54am Subject: Re: Microfoam techniques on Duetto?
Just tried the two-hole tip. Seems a little too overpowering for smaller portions of milk, but I'm going to keep trying it for a few weeks to see if anything improves. Overall, the texture seems better.
Posted Mon Oct 24, 2011, 7:36am Subject: Re: Microfoam techniques on Duetto?
Wow, I can't believe this thread was resurrected, I'd thought it was a dud and given up on it :)
I've made a few changes to my routine that I think has made significant improvements overall. It certainly takes a long time to get used to the steam on a new machine, it's absolutely like learning to start all over again. Over a month or so I think I've finally come closer to figuring the ins and outs of it a little. It's not PERFECT, or more specifically, I'm not 100% consistent, probably relating to not being familiarized with the amount of steam just after a boiler refill versus after steaming one and waiting for another.
My original results were the over-foamed milk I mentioned. Personally I think 255F, ~1.2-1.25 bar is too low for this machine. I'm sure many people have produced suitable results that way, but the 1.8l boiler is a little smaller than the 2l I had on my HX, and at that temp I don't think there's enough steam volume available. Ramping up the pressure helps with that I think. Which I think was expected for the machine, and is one of the big benefits of a DB...you CAN ramp up to high pressure. I put it up to 259 which gives, by my gauge, 1.35-1.4bar. The higher pressure gives both more time before pressure drops to intolerably low temps, and IMO has the ability to produce better foam due to a more forceful incorporation of bubbles.
DaveCUK a former CG member here who happens to be the engineer behind much of the Duetto once noted that he runs his at 1.4bar, and also noted when comparing to HXs that he intended the Duetto to be run at much higher pressure than an HX, thus the "small" 1.8l steam boiler. Why the US default is set to 155F I don't know. That's a hair lower than I'd keep an HX let alone a DB. Dave is also a big advocate of keeping the steam boiler OFF, even advocating turning it off even if it's just for 10 minutes between shots. I'm not sure I agree with him that far, despite the fact that he designed it. He cited life of electronics, valve seals, better for the "environment", safer for kids and pets etc, etc. I don't care about the latter two in this context and I think is an overreaction. The first two I do care about, but I prefer a more "down the middle approach". I don't leave the steam boiler on when I'm not using it, but I'll leave it on for an hour or two if I think I'm using it. The other difference is Dave's in the UK and has the S/N 001 220v model with the 1800W heater. For Dave, flipping the steam boiler on is a 5 minute process. On our lowly 110V US current and 1200W heater, it's a 12 minute process. I think that makes a big difference in how you use it. For him, catching up after an hour of down time means 2 minutes or so. For us it means standing around holding a portafilter for 5-7 minutes. But also in context of steaming, those 220V models with the bigger heater can pump out more steam power because they're recovering faster. We have to tone down our volumes a bit to match the heating power (or use smaller tips and town down the RATE of steaming.) The 2-.9mm hole tips could steam forever. But I'm a speed demon and don't have patience for it :P
Anyway, back on track: Upping the pressure helped. However the other cause of the foamy milk was the pressure drop. When steaming two capps together in a 16oz pitcher, I found the pressure dropping down below the critical .7bar range in the final moments of foaming. That meant slow, cool, moist steam getting incorporated at the end. You CAN get a decent pair of capps that way. But I'm going for perfect, so that just won't do. I decided to split the milk into two 12oz pitchers and steam separately. With this method the pressure never drops down below a little under 1.0bar. I think that prevents a lot of the bigger bubbles from forming that ruined it. For my big lattes I don't mind the bigger pitchers, since I'm not going for perfect microfoam there. The foam is still good, just not art quality in the 16oz. (Note that I'm on the 15A version. 20A may buy another 3 or 4 seconds of good steam.)
I also discovered my old thermometer was horribly broken. I bought a new Rattleware one and found myself steaming for much longer than I assumed I would. The result can be tasted. I don't ordinarily use a thermometer, I foam by time mostly after calibrating by thermometer periodically. Foam by "feel" doesn't work for me because It's "too hot to hold" to my hands long before the thermometer (and taste buds) says its done...which may or may not be related to using the extra thick Motta/Alessi pitchers instead of traditional ones.
Things move fast with the 4-hole tip. My process at this point is about this (after making sure there's a boiler refill, the temp is caught up, and bleeding the wand): I start with filling both of my Alessi 12oz pitchers to JUST above the start of the spout's pouring well (I have no idea how much liquid volume that is, other than that it's "slightly more than is needed for a single cap, poured in a 5oz cup, over a SINGLE shot of espresso (eg, .7-1.0oz)" JonR10 convinced me to get out of my habit of "zero waste"....it just doesn't work you need a little bit of waste in art pouring (but not too much!). I have the wand extended at about a 50-60 degree angle away from the drip tray (rotation) and angled with the top part of the wand, just below the joint completely vertical, or flared out just a bit. I use that to set the angle of the actual wand after the bend. I insert the tip deep into the milk when I start it up so it won't go flying everywhere, and then for the first 4 seconds or so I try to stretch at the top. I error on the side of NOT getting air in more than getting air in. (too deep is better than too high) After that I sink it JUST a little and leave it there, just riding that same depth. I keep the wand inserted in the spout area and JUST barely not touching the wall of the pitcher. I tilt the pitcher toward the spout so that the pitcher wall follows the angle of the wand. Entire steaming process from beginning to end is about 22-23 seconds by time for that tip/volume according to the thermometer. I kill the steam at 22.5-23 seconds. NO MORE than the first 3-4 seconds may be used for stretching. After that you're just blowing bubbles that will become very hard to break up. I wipe/purge the wand after that, pour the art in one cup, then steam the next pitcher for the second cup. (This is why a boiler fill before the first was so important...steaming two 12oz pitchers brings it to be just about ready to auto-fill...which I don't want to happen between pitchers, so I make sure it happens before the first!) :)
This has lead to some of the best microfoam I've ever produced on any machine. Very nice art quality. The trouble is I'm not wholly consistent yet. There are very tight margins for error. If you stretch too long or past that 4 second window, it will be too foamy and the art will never work. Same if the tip is too high during that time and incorporates too much air. Or if you managed to incorporate too little during that time, it'll be too thin and the art won't show. I think those first 4 seconds are the make it or break it point. Not that you can be sloppy for the main mixing stage, but it's easier to do that correctly than the first few seconds. I always have a desire to over-stretch because of the handful of times I understretched....and I end up regretting it. I'm still working on the consistency part.
That and my art pour isn't quite perfect still :) My rosettas usually come out as fine-veined hearts or ferns. Which isn't a bad thing, but isn't what I was aiming for. Part of it is the 5oz tulip cups (Artazza/Terra). They have a very narrow opening and require very small artwork. I often end up spilling it over the edge while paying attention to my pour...which means my art goes running over the side and all over the counter with it :) (In fairness to myself, even Pete Middlecamp at Black Sheep had a little bit of a spillage over the side issue with rosettas in these cups in the video he did for Artazza :) He ignored it well...but it was visible :) I pretty much jumped to the head of the line in difficulty it seems.)
I'm used to the long wands now, and they're not much of an issue. Purging over the drain is a pain, but generally, I like the height other than that.
Still, I'm sure there's others doing even better than myself in the Duetto...and I'm still open to advice from those folks on improving consistency with it.
CrayonShinchan Senior Member Joined: 18 Mar 2011 Posts: 109 Location: San Francisco Bay Area Expertise: I love coffee
Espresso: Izzo Alex Duetto II Grinder: B. Maestro & Vario, Peugeot... Vac Pot: Cona D, Yama Drip: Chemex, V60, Kone,...
Posted Mon Oct 24, 2011, 10:48am Subject: Re: Microfoam techniques on Duetto?
All good feedback, sir. I'm going to have to re-read it from time to time. I'll try upping the temp to 259 as you did to see if it helps any.
I'm curious, is it just my perception that the 2-.9mm tip is faster than the 4-.9mm tip? Maybe the pressure is greater and thus creating an illusion that it's steaming faster?
After reading this, I'm not sure if I should stick with the 2-.9mm.
Also, because the joystick wands are longer than the stock Duetto wands, I replaced the long arm with the Duetto arm so it would fit over my drip tray. I'm wondering if the shorter arm is impacting the way it steams?
DNW Senior Member Joined: 12 Sep 2009 Posts: 11 Location: Wyoming, USA Expertise: I love coffee
Espresso: Alex Duetto II Grinder: Baratza Vario Drip: Technivorm Roaster: Behmor
Posted Mon Oct 24, 2011, 12:36pm Subject: Re: Microfoam techniques on Duetto?
I had installed the four hole tip when I replaced the stock steam arm with to the no-burn arm. After reading this I went back and installed the 2 hole tip, and I think it does seem more powerful, probably just more pressure out of fewer holes. I have only steamed a couple pitchers so far, but I think I like the results better with the 2 hole. I usually use a small pitcher with about 5 oz of milk.
As for the pressure, any concerns of running the pressure too high? How accurate are these gauges? I have my steam boiler set at 249, and that is about 1.4 bar at 6600 feet.
Posted Mon Oct 24, 2011, 1:07pm Subject: Re: Microfoam techniques on Duetto?
DNW Said:
I had installed the four hole tip when I replaced the stock steam arm with to the no-burn arm. After reading this I went back and installed the 2 hole tip, and I think it does seem more powerful, probably just more pressure out of fewer holes. I have only steamed a couple pitchers so far, but I think I like the results better with the 2 hole. I usually use a small pitcher with about 5 oz of milk.
As for the pressure, any concerns of running the pressure too high? How accurate are these gauges? I have my steam boiler set at 249, and that is about 1.4 bar at 6600 feet.
Altitude definitely has a serious impact on steam boiler pressures. I'd go by pressure NOT temperature. There are charts for what temperature = what pressure, but they're based on "near sea level", 259 should be about 1.4 bar for near sea level. But I don't want to think of the pressure at 6600ft! :) The gauges aren't exactly scientific caliber, but I think for our purposes they're close enough to accurate. A boiling point so low should actually give you steam performance like the 220V version I'd think.
In terms of long term wear & tear, I'd think you wouldn't want to run it too high, but in terms of "exploding boilers" and safety issues that's why there's a safety relief valve on these things. If it over-pressurizes the relief will pop.
CrayonShinchan Said:
I'm curious, is it just my perception that the 2-.9mm tip is faster than the 4-.9mm tip? Maybe the pressure is greater and thus creating an illusion that it's steaming faster?
Definitely not faster. 2x .9mm versus 4x .9mm...double the surface area. There's certainly more heat being released out of the 4 hole, and the pressure gauge will confirm that. Not quite 2x though, as you've both seen the steam will come out a bit more forcefully from each hole with a 2 hole tip but, overall, less steam is actually coming out, which is why the heater can keep up with it a bit longer than with a 4 hole tip. 4 holes are faster, but each will behave differently. The 2 holes give a little more time to work the stretch than the 4 holes will. I prefer speed, and, the one thing I like about 4 versus 2 hole is that 2 holes can be directional. Depending on where the holes are pointing affects the flow of steam, whereas 4 hole tips are spraying in 4 directions. It's quasi-directional, but generally, not in as significant a way. I liked the result from the Isomac 2 hole tip on my HX when I used it....I just couldn't suffer along with the slow pace. 4 holes are less forgiving due to the speed though.
Also, because the joystick wands are longer than the stock Duetto wands, I replaced the long arm with the Duetto arm so it would fit over my drip tray. I'm wondering if the shorter arm is impacting the way it steams?
It's not that much shorter. actually. I thought of putting the original wand on, but I realized I could swing it over the drain with the long one if I gave it a wide swing. It works. It's a little quirky, but it works. I don't think it affects the steam one way or another though. I'll say that with the long one I like how I can rest my wrist on the drain tray to steady it. I wonder if it would be at the wrong height if I did that with the shorter wand?
DNW Senior Member Joined: 12 Sep 2009 Posts: 11 Location: Wyoming, USA Expertise: I love coffee
Espresso: Alex Duetto II Grinder: Baratza Vario Drip: Technivorm Roaster: Behmor
Posted Mon Oct 24, 2011, 5:34pm Subject: Re: Microfoam techniques on Duetto?
"2x .9mm versus 4x .9mm...double the surface area."
My two-hole tip has larger holes than my four-hole. Not sure the exact size, but they are definitely bigger. It seems like the two-hole is a little more powerful, and is harder to finesse the stretching phase. Once you sink the tip, it seems like it shines over the four-hole, incorporating the foam better.
Posted Tue Oct 25, 2011, 7:47am Subject: Re: Microfoam techniques on Duetto?
DNW Said:
"2x .9mm versus 4x .9mm...double the surface area."
My two-hole tip has larger holes than my four-hole. Not sure the exact size, but they are definitely bigger. It seems like the two-hole is a little more powerful, and is harder to finesse the stretching phase. Once you sink the tip, it seems like it shines over the four-hole, incorporating the foam better.
There are 2x 1.2mm, 4x 1.2mm hole tips, and 2x .9mm and 4x .9mm hold tips out there. And then there's that crazy San Marco 6 hole tip we won't mention :)
Yes, a 2x 1.2mm hole tip may actually let out MORE steam than a 4x .9mm hole tip. As the diameter of the hole increases the lower the pressure and greater the volume of escaping steam. Those large hole tips were more popular before the 4x small hole tips became common. And the 4x 1.2mm hole tips are the commercial standard still on the larger machines with more power, at least on the steam arm intended for steaming larger pitchers. Hard to top that speed!
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