Watching a video like this makes me want to grab a Bialetti. No romance at all....

It's not as romantic, but I do like the ideas they bring in that you change for instance the dwell time, and that the rest of the parameters are not affected. With most other machines, everything is 'connected'. If I have a normal machine, and the dose is slightly smaller, for whatever reason, the shot time is decreased, and the brew ratio has increased. With the Duvall, it would be just the brew ratio, without any knock-on effect. So the Duvall should theoretically be much more forgiving.

Not for me. Can't get much better of a show than 3 or 4 dancing levers.

Not sure what the Bernoullis would think about the physics of "controlling the flow independently of the pressure."

Unless you exceed the pressure capability of the machine, the flow is independent of pressure. Put in a Turkish grind and the pressure will skyrocket, put in french press grind and the pressure will be closer to zero, but the flow will be constant for both. You might argue about the usefulness of that feature, but within its pressure limits, it's certainly capable of pulling off flow independent of pressure.

I've spent a number of hours talking to Gideon and he certainly seems to know what he's doing and have a clear idea of the path he's on. I expect this will be a game changing machine for those those that learn to use its features. Whether that be a roaster who distributes new recipes with each delivery of coffee or a small shop trying to make the best espresso possible. And if he gets it reliable enough, it's a suitable replacement for the ever to common Linea or Slayer with a Robur and Major in a hip looking shop making bad espresso. A Duval and a Swift Mini serviced by decent roaster ought to be able to significantly raise the quality of the coffee served at your average coffee shop.

And yes, I'm a fan boy. I made the first post about this machine a couple years back when I showed up in a corner at SCAA and everything I've seen and heard makes me believe it will be a significant entry in the high end espresso machine world.

Ira

Looks interesting, but, I'm sure it's quite spendy to buy and I shudder to think about the cost of replacement mother boards, CPUs, etc over time.

Bluecold wrote:...you change for instance the dwell time, and that the rest of the parameters are not affected. With most other machines, everything is 'connected'.

Everything is still connected.

Gideon is a sharp guy and has put forth an innovative concept.

However, the laws of physics still apply.

The FC-1 has a user-set fill rate and fill pressure that start the shot. The machine dispenses water at the desired fill rate until the fill pressure is reached. Very similar to a PI phase on the DE1.

This is followed by a user-set dwell time, where the machine literally does nothing for a period of time to soften the puck. Longer dwell time will result in a lower peak brew pressure during the remainder of the shot.

Finally, you get to the wizardry of the machine. But before we go into that, let's look back at the impetus for such wizardry. Way back in 2006, Andy Schecter formalized the concept of Brewing ratios for espresso beverages. The idea behind this is that a 1:2 normalle pulled at 22s is more like a 1:2 normalle pulled at 38s than a 1:1 ristretto is like a 1:3 lungo both pulled at 30s. So we home baristas bought into the idea that the ratio makes the beverage what it is and the timing tweaks that same beverage into what our preferred embodiment of that beverage might be. We have scales, we are proud. But by and large 9 bars prevailed for a long time. Sure, some have moved to 6 bars, or 8 bars, and then we have profiling machines that do all sorts of stuff, but let's look at a shop pulling shots all day. They want this morning's shot to be the same as this afternoon's. They adjust the grinder throughout the shift to keep the yield and the timing on par so that the shots are ultimately the same beverage and have the same characteristics throughout the day. The shot timing and yield change because in most machines the pressure is fixed...

Duvall takes the idea of a brew ratio one step further and says a 30s 1:2 normalle pulled at 6 bar is more like a 30s 1:2 normalle pulled at 9 bar than a 22s and a 38s 1:2 normalle both pulled at 9 bar are alike. So now, the shots are (allegedly) remarkably similar and brew pressure is now an indicator to the barista to tighten the grind proactively to stay in the sweet spot. In theory, sink shots become a thing of the past.

In order to accomplish this, the user sets the desired beverage yield and total shot time along with the fill rate, fill pressure and dwell time as discussed above. They also set a "flow ramp", which we'll get into later. The machine backs out the volume of water dispensed during the fill stage and the amount of time through the end of dwell and calculates a flow rate required to get the desired beverage weight in the cup at the end of the shot time. The algorithm assumes about 40ml stays retained in the puck and then dispenses the remaining water into the group at the calculated average flow rate. You with me so far? It's like a DE1 flow profile, but the machine determines the flow rate for you, based on what you want in the cup and how the beginning of the shot has transpired.

The flow ramp setting biases this flow towards the beginning or end of the shot, depending on the setting and it ranges from -1 to +1, with 0 being a constant flow shot at the calculated flow rate. +1 starts the shot at zero flow and ramps the flow up until it hits twice the calculated average flow rate at the end of the shot. A flow ramp set at -1 does the opposite and starts the shot at twice the calculated flow rate and ramps down until it hits zero at the end of the shot.

As Ira noted, the important distinction with this machine is that all shots set with the same yield and duration end at the same elapsed time with the same yield in the cup, but the pressure at the puck during the shot is up to the barista and the profile settings. In theory, a given profile should remarkably consistent through the day with the machine giving visual feedback through the pressure log to inform the barista of steps they can take to keep the shots dialed in before the customer can taste a shift in flavor.

In theory, this is all a very good thing.

Ok, that was a long post, so I'm done.

Cheers!

- Jake

*Edit*
I should add that the flow ramp values are adjustable between -1 and +1, not like you just get 3 options, so the amount of flow decay or increase is quite controllable throughout the shot, it's just always a linear relationship.
*/Edit*

Am looking forward to a 1-group version in 120V. I wonder if Square D will contact them regarding logo infringement. Instagram photos make me hope they progress to a wiring harness/loom to tidy that rats nest.

ira wrote:Unless you exceed the pressure capability of the machine, the flow is independent of pressure. Put in a Turkish grind and the pressure will skyrocket, put in french press grind and the pressure will be closer to zero, but the flow will be constant for both.

Um, exactly. The flow is a function of the pressure and resistance; it is not independent, i.e. you can't adjust each independently. It seems like a profiling machine with flow based controls rather than pressure based controls.