Hi there! This is the DE1PLUS, and I will give you a quick demonstration of how flow profiling works.
Now, this is something new to the espresso world,
so bear with me here as I explain how it works,
because it's quite different from how things like pressure profiling work on traditional machines.
So here we are with the DE1PLUS. It's just booted up and warmed up, I haven't done a shot yet.
I'm going to hit configure.
And here I've got my flow profiling curve.
I can choose pressure profiling, flow profiling, or create something advanced.
Now, to make things simple for myself, I am going to first choose one of these profiles -
that's a declining flow profile -
and then click here and edit.
The way the flow profiling works is you choose the speed of the water that you want,
and the pressure is automatically adjusted to achieve that.
Since lever machines - where we are doing this for espressos - or here with a paddle on the espresso machine,
those baristas are often looking at flow and adjusting it by hand to achieve the perfect espresso.
That's what we're trying to do here, but automatically for you.
So let me run you through what we're looking at here.
Here we've got a pre-infusion:
the preinfusion on our espresso machines is always flow based,
because talking about pressure during preinfusion doesn't make sense. There is no pressure.
So
4ml/sec is about what a commercial machine is doing,
between 4 and 4.5 ml/sec when it's not doing preinfusion
but when it has what is called "jiggler" inside it, which helps the puck swell gently as the shot starts,
but fairly quickly.
So here we are with a 4ml/sec pre-infusion.
I've set the 13 seconds of preinfusion which actually won't happen.
And the reason it won't happen is because there's also a feature in our machines
that automatically eggs its pre-infusion when the puck is detected as being fully saturated.
At this point here, I've set the 4.1 bar,
and I can set anything I want here,
but generally 4 bar is a good measure because it means once you have a lot of pressure on the puck,
well, there's no possibility to there being a dry spot on it.
So I just set this to 4 bar,
leave it 13 seconds, 15 seconds, 30 seconds
whatever you like because the reality is it will exit when the pump is detected as being saturated.
Ok, the next step after the puck is saturated is to basically regulate pressure
automatically by controlling the flow.
So what we've got here is a hold period for, say, 2 to 2.8 ml/sec for 10 sec or whatever we want,
and then we like to decline. Now, the reason to do a the declining flow rate
is because as the coffee puck is being more and more eroded, the material left behind is harder to remove.
So the idea is to rather than having the speed of the water increase,
which is what happens in a pressure profile machine through erosion,
we want the flow to decrease, so that more time is spent extracting the remaining material.
This is a way to really control acidity on the shot.
Now, generally, I'm actually not using declining flow feature,
because I got beans that are more lighter roast, medium to light roast, and I like a bit of acidity on the mouth.
So I don't want to over-control it.
So in this case, I am actually going to remove the decline
and
do something like this.
Ok?
Now
finally, you might notice this thing that says "five bar start".
Now, the reason that's there - and it might seem confusing,
but this is something that's emerged in conversation with some coffee gurus
is that
if you go to flow profiling and you haven't compressed the coffee puck,
then all that's going to happen is that the water is just going to pour through.
So we've got an option here. If you're not compressing the puck during the pre-infusion,
you can ask the DE1PLUS to put enough water in,
the puck will get compressed,
and then switch the flow.
So I'll give you an example where that would be the case:
let's say we did a really slow pre-infusion for 30 seconds at 0.5 ml/sec -
so what's called a Slayer shot -
if you went then 2.8 ml/sec, the water would just gush through.
So
you would probably, in that sort of espresso shot, set the minimum bar to something like 3 or 4 bar
so that the puck does get compressed.
Now in this case, we're exiting pre-infusion anyway when 4 bar is reached.
So we don't care. We don't use that feature.
Alright.
So, in the end, this espresso shot - and it's a preset already in the machine - is very simple:
4 ml/sec preinfusion until the puck is set,
and then 25 seconds at 2.8 ml/sec.
Now let's do an espresso shot and see what this looks like.
That's what my coffee looks like
I did 18.5 grams
This is ready to go, so I'll hit save.
And now we're getting an espresso. We're going to watch what the curves look like when the espresso is being made.
We're going to zoom in on pressure and flow.
Now, this chart here has combined pressure and flow on one page;
on left-hand side in green is the pressure axis,
and the right-hand side in blue is flow.
And the reason we did this is that the lines will be as big as possible
and you can see the relationship between pressure and flow at the same time.
Now, the shot has just started,
and I need to put a cup here quickly.
You can see flow is now 4ml/sec, pressure is 0 going up climbing.
There's the green line, and as soon as it crosses - boom!
it crossed 4 bar. Now there's that line.
And you can see that the flow control has now kicked in.
This dotted line is our goal, which is 2.8 ml/sec,
the machine is trying to get to it. Looks like it's about 2.72 ml/sec,
and the pressure that's occurring in order to obtain this flow
is 9.7 bar.
Now, I had pre-programmed this shot to be 25 seconds of constant flow after pre-infusion,
pre-infusion took 10 seconds,
so the whole shot took 35 seconds. I don't have to do anything.
There we are with 18 grams of coffee,
and 34.8 grams went into my cup,
so about a 2:1 shot.
So on the mouth, this of kind of espresso is quite low acidity.
We're going quite big and floral.
This is a medium/medium light roast from a friend of mine who roasts in Italy.
And I don't need any sugar in it because it's really controlled,
the mouth feels great. I'm just very happy with how this espresso tastes.
And I didn't have to do much!
I just plugged in the shot, 4 ml/sec pre-infusion, 2.8 ml/sec flow,
and - boom! - there's my espresso.
Now, as the beans change in character, the pressure will get automatically adjusted daily,
and the espresso won't change much in flavor because it's really flow
that is the most important determinant in how good your espresso is.