My brand new Duetto IV is producing what to me at least looks like very wet steam. The Duetto is 3 days old, and I'm using soft mineral water with the reservoir (i.e. not plumbed in).

On the factory default settings of 123C steam temp it gets to about 1.1bar of pressure at steady state. I purge the steam wand for 1-2s into the drip tray (some water comes out). I then steam some water in a cup for 20s. The water gains about 18g of weight in the process. This seems too much to me, but I am a complete beginner. Can someone tell me if if this is too much please?

If I switch the machine off, purge 50g of water from the hot water tap and then repeat the experiment, I get the same result so I doubt it's because the water sensor is too high? But maybe it's so high that purging 50g isn't enough? I cant' really purge any more water and retain enough steam pressure to steam for 20s to repeat the experiment if the machine is off.

I've read some older Duetto models have an anti-vac which purges into the water reservoir. I don't think I have that - there is only one hose in my reservoir and as the steam reservoir gets close to 100C during heat-up I hear the anti-vac valve hissing for about 5s with a small puff of steam coming out of the top of the machine before it shuts off - which to me sounds like the anti-vac is operating properly (and venting to the outside rather than into a hose) and can't be causing the wet steam.

Everything else seems to work fine - the machine dribbles quite a few drops of water into the drip tray on heat-up which then stops once warmed up.

Any ideas gratefully received with thanks in advance!

Welcome to HB Stephan

I think your steam pressure is a bit low at 1.1bar, it should be more like 1.6bar. Steaming water in a cup for 20sec I think is too long. I purge the condensate from the steam wand into a rag for a second or two and fill up the cup I'm about to use to pull the shot with water from the hot water spigot drawn from the bottom of the steam boiler to preheat the cup, wait for the boiler to recover and the reinserted portafilter to heat up before pulling the shot. Drawing water from the hot water spigot to preheat the cup also triggers a demand to fill the steam boiler so that the shot won't be pre-empted by a boiler fill.

I purge the steam wand often so that only small bursts are required to drain the condensate and steam boiler pressure is quickly restored. You'll develop a feel quite quickly for the right amount of purging.

Seems that other than slightly low steam boiler temperature and pressure that you Duetto is functioning well.

Great choice for an E61 in my estimation.

What a coincidence. I just picked up my new Duetto 4 replacing my 11 year old Duetto 3 (will be selling soon) For myself there has been no difference in the steaming ability between the two machines. It was kind of cool that three extra variety of steam tips were included with the machine. I am just using the standard tip that was installed on delivery, and am satisfied when I make my one cup at a time.

BaristaBoy gave good advise and should help you out. All in all the Duetto is a great machine. I wonder why it doesn't get much attention here at HB?

Thanks Barista Boy.

My pressure gauge has the green zone 1-1.5bar. 1.6 bar would be in the red zone - isn't that kind of high? I don't want to blow it up! Will try a higher temp setting to see if things improve.

I should have added I'm using the 2 hole steam tip, but the Duetto did come with a selection of others as chipman says. Also a very very cool chart showing the time relationship between boiler pressure and milk temp for the different steam tips over time. It's a wonderful machine even if I haven't got the hang of dry steam yet.

Agree 1.1 bar is low.
No burn wands tend to have poorer steaming capability.
The machine should have a pressure rating on the sticker. Sometimes you can see the release pressure on the safety valve. ≈¾bar is the minimum margin.

The Duetto IV is a PID machine. It is impossible to set the steam boiler temperature above 128, which, I think, is equivalent to 1.5 bar. For what it's worth, I run my Synchronika with the steam boiler PID temp maxed out (which is about 2 bar). I suggest you give max temp a try.

LittleCoffee wrote:I then steam some water in a cup for 20s. The water gains about 18g of weight in the process. This seems too much to me, but I am a complete beginner. Can someone tell me if if this is too much please?

I used to measure how much water was added when steaming various volumes of milk for reviews, but there was so little variance, I haven't bothered in a long time.

That said, 18 grams (~0.6 ounces) doesn't sound like a lot for a typical latte/cappuccino. If you want the driest steam possible, you can lower the steam boiler's water level by pushing down the water level sensor a smidge. That increases the "headspace" of steam, but it comes at a cost of steam pressure stability since the remaining boiler water has less thermal energy to impart and semi-commercial espresso machines don't have enough heating element wattage to keep the pressure steady for much more than 15-20 seconds.

I suggest buying a rubber sleeve for your steam wand (<5$), slipping it on and pulling out that ptfe (or whatever the heck it's made of) tube inside of the wand. The steam quality will improve drastically.

You can also try setting the machine to 20amp mode if you have a 20amp dedicated AC line. That would result in a faster recovery with a slow decline in boiler pressure.

Yeah, I agree. If you have a dedicated 20A line available, I would highly recommend using your machine in 20A mode. Chris Nachtrieb has always said it doesn't matter in the home setting, but I certainly noticed a difference. It doesn't affect the steam quality (in terms of dryness), but it sure does affect pressure and recovery time.