I'd like to show you how you can use this real-time controller on the Decent Espresso machine
to either tweak and improve the shot that's basically going okay,
or how to completely take over the espresso and run it as if it were a manual machine.
Let's first show you how to use it to tweak an espresso that's basically okay.
We're going to use the default profile right here,
which is the one we recommend most people use for just good espresso.
Hit the Start button here.
Here we have the shot pre-infusing, the pressure is rising.
And now, the pressure is going to start decreasing to compensate for the puck eroding.
Now, let's say that we'd like the pressure to drop a little faster because the puck is really eroding quickly;
each tap here is decreasing it faster than it has planned.
So imagine that your puck is starting to break up and the liquid is too light,
you decide to lower the pressure quickly.
And then, when the shot's done, you just stop it.
So what I just did with this espresso is take the default profile,
and when I saw it was going a little clearer than I wanted - known as dark coffee -
I decided to lower the pressure. And I did that by tapping on the group head.
And each tap was a 0.1 decrease in pressure, and it remembers it and just continues on with the espresso.
And then I stopped it at the point I wanted.
In this next example, I'm going to use flow profiling to show why you might want to use the real-time controller.
We're going to use the flow profile for milky drinks.
We've got preinfusion happening, pressure rising;
the puck has gone to 12 bar, which is much higher than I want.
So I'm just going to tap a few times to lower the flow,
which will have an impact right away on pressure.
Now, pressure rises to the square of the flow,
so small changes in flow have a big effect on pressure.
Now, imagine I wanted to drop it a little more. Let the puck slow down,
and now stop my espresso.
What I was able to do here was salvage an espresso where I had gone to 12 bar,
and I wanted to bring the flow down to 7, 8 or 9 bar - some range of good espresso -
and I was able to do that manually.
And when I saw the espresso starting to get too clear, I lowered the flow some more and then stopped it.
So that's an example of being able to tweak a flow profile shot;
it's going not too well, and to salvage it,
so that instead of throwing it out, it's going to be completely acceptable.
You've got a few seconds where the pressure is too high,
but you quickly salvage the situation and made a good drink after all.
In this next example, I'm going to manually control the espresso from scratch.
Now, I'm going to rise to 9 bar and then go down to 6 bar.
There are presets to do that, but I'm able to interactively decide when I want the pressure to change.
Now to do this, I'm going to take a very simple profile;
it's just the e61 profile that goes to 9 bar, and I'm going to interrupt it before it goes to 9 bar.
When this espresso starts, I'm going to put my finger here to raise the pressure to 9 bar.
Now, 9 o'clock on the clock face is 9 bar.
And as the espresso is extracting, I would traditionally be lowering the pressure like this
to compensate for the fact that the liquid's becoming less and less dark.
I'd be watching it here, I'm lowering it and lowering it
until I have enough in the cup that I'm happy,
and then I hit stop.
What you just saw is an espresso that I made completely controlled in real time with this controller;
I went to 9 bar and then slowly reduced the pressure as I saw that was the right thing to do with the coffee.
Finally, I'm going to show you how to do a flow profile shot completely manually.
Now, there are some traditional espresso machines that can do this,
and it can be a very powerful technique if you know what you're doing.
To make a fully manual shot, I'm going to create a flow profile with no water going out,
so I am completely in control of things.
To do this, I go to settings - preset - I create a new preset -
its "flow profile"
and what I do here is lower the flow down to 0.
I'm going to increase the time to 1 minute, so I have all the time in the world to do what I want.
And now start it.
At this point the espresso has started, but no water is flowing because this is a profile with no water.
But I'm in flow mode, so if I move my fingers here to 4, I'm now doing a 4 ml/sec pre-infusion.
I've risen pressure up to ridiculous heights, so now I'm going to lower it down here,
and you can see now the pressure is doing something sensible.
And here I am with my finger controlling every instance of the espresso.
Now, I typically would want the flow to diminish over time,
like so,
and if I let go, I'm redoing a traditional lever shot because the pressure is going out manually,
and then I can choose when to stop it.
Now you can see that was a very powerful technique because I was able to control pre-infusion,
the flow during the shot, slowed things down, that pressure decrease manually or automatically.
So I can do everything, but it does take some mastery to do that,
which is why most the time people just use the presets on the tablet,
and then they use the tweaking mode to slightly improve them.
But it can be a lot of fun, too, to just make an espresso the old-fashioned way, totally by hand.
Why is it sometimes controlling flow and sometimes pressure?
Now, what happens with the Decent Espresso machine is that when you touch the controller, whatever mode you're in is what you take over.
So if you're doing a normal pressure profiling shot
- let's say the default espresso -
when I take over the controller, I'm controlling pressure.
If I make a flow shot, now I'm controlling the flow when I go here.
That gives you the best of both worlds because no other machine exists that allows you to control flow or pressure with equal power.
And that's something that's pretty exciting.
I hope this introduction gave you some ideas of the power of the Decent Espresso machine's real-time controller,
and I hope you let me know what you get up to with it.