Water debit and screens

Recently, I’ve been looking more closely at the machine end of what I do, as opposed to the bean, barista, and latte art side of things, with a view to better understanding how to choose upgraded machinery – and it’s been quite interesting.

(Beware: dull and geeky post)

I always thought the screens on our Ducale at work must be pretty poor, and that the flow of water seemed rather violent, and after reading the following threads/videos…


…I thought I’d upload some footage, and take a reading of the water debit on our machine, for the record, and to see what people think…

The similar examples below show the flow with hot (HX) water (1 and 2), leading to the cooled water (1b).

(Apologies for the sideways view – can’t figure out how to change it!)

1 1b


The full and rather impressive extent of the dispersion is not very clear in the clips; the finer sideways sprays are trickier to spot.

I measured the unrestricted water debit for the first 10 seconds from activating the pump, and it filled two of our 10oz cups. That’s nearly 600ml. That’s right: not 60ml – 600ml. Good, eh?! I took readings from both groups, with both the super heated and cooler water, and the debit was roughly the same on each group, although the group videoed is my preferred group which I use for all my shots, as is has the ‘best’ screen, and I find it gives the best extraction.

The machine operates at 9 bars when pressurised.

These are pictures of the group/screen, and of the two full 10oz cups after a 10 second flush of the group:

ducale left screen

ducale water debit - 20 oz

This is the machine I have been using to make espresso for the last two years, since arriving at the plan. This is the machine I often describe as ‘loved and loathed’ and as having ‘some issues…’. This machine is the one I have used to practice and develop most of my espresso technique on, and it’s the machine I used to prepare for my set in the ukbc this year. Prior to this, I had only used a superauto, and since being at the plan, I’ve only had a few very brief sessions on two S5s, a Linea, and the San Remos in competition. So I’ve had very little to compare it against, and have simply tried to use it to my best ability, and develop my techniques as well as possible in order to get the best espresso from it that I am able to.

HX temperature issues aside, any thoughts on on the water dispersion and water debit from this machine folks..? Don’t mention preinfusion, gicleurs or needle valves. Only joking – please feel free to 😉

(Please note our machine may or may not be representative of its model and make)

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