Decent Espresso Machines (DE1) - Any thoughts?

[MrJack]

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"Basket temperature goal mode"

In every other espresso machine, you set the water temperature, and that's what the boiler heats to. Say, 90°C water. But, by the time the water leaves the boiler it's gone down about 6°C, sometimes more, sometimes less (depending on the machine). And then the espresso coffee grains themselves are at 20°C (room temperature) and when they make contact with the water, the slurry is a temperature which mixes the water and the coffee (and potentially the cooling effect of the portafilter if it wasn't preheated)

I've made this ugly chart to show what we're doing. Other machines have a constant water temperature, so they have a linear climb toward their goal. Our DE1+ machine can dynamically vary the water temperature, to get the puck temperature to the goal faster.

I like to think that this feature will arguably make better coffee, since different products are extracted from coffee at different temperatures and there really are different flavors at different temperatures. People really fixate on water temperature for pour-over coffee for this reason.

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Have you measured the puck temperature profile? Fairly sure it isn't normally linear - http://www.diycoffeeguy.com/espresso...n-temperature/

[>decentespresso]

article charts

Have you measured the puck temperature profile? Fairly sure it isn't normally linear - Espresso extraction temperature - DIYCoffeeGuy.com

While we don't have a temperature probe in the coffee puck itself, because that would cause channeling, the DE1+ has a temperature probe 4mm above the puck, and this is what is charted in real time when you make an espresso with that machine.

The article you pointed me at was interesting, but as the charts are neither "over the time of a shot" nor do they include flow rate, I'm not sure what to make of them.

The article says this:

These results are still only of limited validity. It is important to note that these profiles do not reflect the temperature over time, because we have not accounted for flowrate, nor the (more difficult) rate of heat transfer!

In a few weeks I'll be programming an option to disable the varying-water-temperature feature in the DE1+, and I'll be able to provide an answer to this question, with charts that show real data. We'll have an "inlet temperature" probe, as well as a probe on top of the puck, and we'll be able to see if an unvarying water temperature causes a linear puck temperature increase, or something else. I suspect you're right, that it's not linear, but let's wait and see what the data shows.

[>decentespresso]

welcome Ben

Australian Ben Champion, a regular from Home-Barista.com, has been helping us a ton, on a volunteer basis, to simulate the fluid paths in our group head, and has been running similar simulations in other parts of our machine; most recently our mixing chamber:



Ben's quirky and competent approach has really helped in the past month, and so we've decided to make his position official and paid. You'll shortly be seeing an unflattering cartoon representation of Ben appearing on our "about us" page.

His first project is to take the "flush diffuser" (or call it the "flush slower-downer" or the "try not to splash customer device") from Ray's concept, which we filmed here

which taught us that it worked right, but that a lot of the complexity was unnecessary:



which Ben has now turned into this 1st draft:



and we've got a revision or two on that to go (this week!) before it's done. Along with the USB port (most likely now to be USB-A) these are the last two things to finalize.

[>decentespresso]

knockbox design done

We've been literally banging on our frankenstein-knockbox prototype for two weeks, and I've given the go-ahead to the factory to start making it. It'll be about 10 weeks wait now before they arrive : the long wait is because moulds this big take about 2 months to make. https://decentespresso.com/knockbox

We spent $350 recently to try out the larger size, and because it was too large for a CNC machine, it had to be welded from two parts (it looks sort of like Frankenstein's head). We decided we liked the larger size, because it felt damned solid (it's made from 3mm thick aluminum, not plastic) and because it never filled up. We think it's big enough to use in an office where lots of people are making espressos all day.


Just to the right of the knockbox, you'll see our hotrodded Hey Cafe pro grinder https://decentespresso.com/pro_grinder which we've modified to have weighed dosing, using a brewista scale. We're CNCing the hopefully last iteration of the stand this week. We ended up attaching the scale stand to the rubber feet of the grinder, so that you can adjust the distance from the spout by loosening the rubber feet, and when you have it where you want it, you tighten the rubber feet to lock the stand in place.

We've also added a bluetooth on/off switch to the grinder, but we're not yet ready to sell that as a product, because I haven't written the software, as I'm also waiting for our bluetooth scale https://decentespresso.com/scale to be finished.

And speaking of which, I received new firmware and the 4th beta of our scale today, and just about all beta problems are now fixed. I hope that in about 2 weeks I can give manufacturing approval to that, and then the scale will take about 10 weeks to arrive from the factory.

Here's a render of what the knockbox should look like, when it arrives in 10 weeks:

[>decentespresso]

The Design Phase Has Ended! Now What?...

We've now frozen the design of our espresso machine and we're working with manufacturers to make all the parts. About 90% of our machine is made from custom parts, so each one requires an extensive conversation with a manufacturer, as well as detailed drawings and price negotiations. Each type of part also has different lead times, from 7 days to 2 1/2 months (for parts that require a mould). Of course, we have companies all lined up for this, but until the final drawings were done, we couldn't get a final price quote and other "details".

We're currently interviewing 3rd year students from Hong Kong University of Science and Technology HKUST - Hong Kong University of Science and Technology and we're hiring 10 of them as summer interns. They're going to be building your espresso machines! We'll have each intern spend time at every station, so that they get a wealth of real world experience.

We originally thought we'd work on building a dozen or so machines at a time, from start to finish. However, to speed things up, and because not all the parts will be here at the same time, we're going straight to building 200 espresso machines at the same time. We're working on "sub-assemblies", which are groups of components that perform a function, such as the water heater assembly, or the water mixing assembly.

In terms of a calendar, this means that:
- nobody will get a machine from us in June
- but everyone who bought a pre-release machine should get theirs in July.
- this does delay our submitting our machines for UL certification, because we likely won't have all the parts we need until end-of-June/early July to completely finish any machines.
- so the 100 "final release" customers won't see their machines until August.
- However, since we're building all the "final release" machines at once, as soon as we have UL approval we'll be able to ship them all very quickly.
- In August/September, depending on how the customer reviews go of our pre-release versions, we'll decide whether to expand our manufacturing space and how many recent engineering graduates to hire. Our landlord, who owns the entire building floor (about 300,000 sq ft) and is a big espresso fan, has bought her own pre-release machine from us, and offering us multiple spaces to grow into with no commitment. That's helping us sleep at night!

Looking at the calendar for when parts will start arriving here, we think that:

Starting June 1:
- the heater subassemblies can be worked on.
- PCBs can be manufactured in house
- tablets can be configured (load from "adb") and mounted to a steelie stand
- legs can be assembled with rubber feet

Starting June 15:
- the left panel can be assembled (power supply, mini manifold, OPV)
- the main manifold (and top bar) can be assembled, though all - valve types might be not be in stock (the specialist valves from Italy might take 3 months).
- the wire harnesses can be made
- the group head can be assembled

Starting end of June:
- the middle panel can be assembled (both pumps, electrical relay, mounting heaters)
- the PCB can be mounted to the back panel
- the steam wands can be mounted
- tubing and wires can be connected to their final position
- reconfirming current postal addresses of 100 pre-release customers.

Starting 2nd week of July:
- shaking test for 12h, and 24h constant-espresso-making burn-in test of each machine
- localising android tablets to the customer's country and language
- send out machines to UL for certification
- boxing and shipping 100 pre-release machines
- accounting follow up with all "50% deposit" customers to pay remaining balance

Starting in August:
- receive UL certification, send out already-built "final release" machines (if no changes)
- or make changes to existing 100 "final release" machines based on UL mandated changes.
- Internet reviews of "early access" machines should be live by then, and we'll know how many machines we should build for the next run (between 500 and 5000 machines, depending on demand).
- Place advertisement to hire recent engineering graduates, start interviewing and hiring.

Starting in September
- summer interns go back to school
- recent engineering students start permanent jobs with us

Starting in October:
- build the next set of espresso machines

Start in November:
- start shipping, in volume, our espresso machines.

[>decentespresso]

DE1CAFE progress

Now that coffee-fiend/mechanical-engineer Ben has joined us, I have some extra engineering muscle to put toward the DE1CAFE model.

Ben's timing is good, as Joao and I just finished designing the weighing-feature compatible drip tray cover, which you can see below, for the first time. Each of "load cells" for weighing will be under each of those four corners of the drip tray cover. This should allow for a pretty invisible weighed-espresso feature, both with automatic-stopping of shots at the right weight, but also being able to chart espresso-in-cup weight during the shot itself.

It's not an entirely bad thing that Ben is in Vancouver and Joao is in Portugal, as this allows them to make progress on the DE1CAFE without distracting the rest of my team, who is here in Hong Kong, from getting the DE1 series of machines manufactured.

[>decentespresso]

Barista Kit Finally Shipping !

One last little piece of foam finally came in today, and we can finally put together our barista kits https://decentespresso.com/barista_kit and ship them out to everyone who pre-ordered. Really, really sorry for the delay, but I'm hoping you'll be happier with the result, as we switched from our originally planned cut foam, to using moulded-to-shape foam covered in spandex. Nicer looking, smells better, and much easier to clean.

[>decentespresso]

NEWS: whoops! barista kits take time to assemble!

Whoops! Even with four people working all day, we're only going to manage to ship 1/3rd of the backlogged barista kit orders today. Sorry! A lot of them are custom orders (note the yellow highlights on the orders) and we want to make sure we don't mess any orders up! On the positive side, it's lovely to see how many of these orders are for many different products we sell (you can see the little image for each product on all the invoices) https://decentespresso.com/barista_kit

[>decentespresso]

Two hand-made steam wand prototypes for the DE1CAFE just arrived today. Looking forward to trying it out. We have 1 and 4 hole steam wand tips for this.

[Shortyesquire]

Hello decent. You have probably already answered this already. I'm building a new house in the next couple of years and hoping to get a plumbed in machine. Will the DE1CAFE be the only machine that you make that can be plumbed in. Also how will servicing and installation work in Australia for the DE1CAFE?

[>decentespresso]

Hello decent. You have porbably already answered this already. I'm building a new house in the next couple of years and hoping to get a plumbed in machine. Will the DE1CAFE be the only machine that you make that can be plumbed in. Also how will servicing and installation work in Australia for the DE1CAFE?

The currently available "PRO" option allows the DE1 or DE1+ to be plumbed in. That's a much less expensive option than going to the DE1CAFE and it'll be shipping sooner too, as we have the plumbing R&D all done (that's what we use here at our factory). https://decentespresso.com/compare

Installation is easy, I don't think you'd need help with that, but service is currently via shipping a machine back to us, if it's really dead, otherwise we can supply parts to whoever you have working on your machine locally.

[Shortyesquire]

Thanks decent. Does the pro option mean you have to plumb it in or does it retain the water tank?

[>decentespresso]

Thanks decent. Does the pro option mean you have to plumb it in or does it retain the water tank?

Plumbing is optional. The water tank remains, as it is preheated water (same design as our other machines) but then a separate valve/pump box tops the tank up automatically after each shot.

Here's a diagram:

[readeral]

Hopefully warm largely still water in tropical locations won't become an accidental attraction for mosquitos. Obviously you can empty the water and clean it out, but would be annoying to do if if they keep finding it.

[Shortyesquire]

Hopefully warm largely still water in tropical locations won't become an accidental attraction for mosquitos. Obviously you can empty the water and clean it out, but would be annoying to do if if they keep finding it.

Wouldn't the water tank temperature be too high for misquito larvae? They would also need to be undisturbed for a week.