Decent espresso

[Obnic]

According to Rasmus:

I can achieve something like ‘blooming’ with a Vesuvius. (I use a Ceado E92 conical grinder.)

I use a 15 second 2 bar preinfusion then drop the lever half way, which keeps the pressure in the group without building on it. After 20 or so seconds I start the pump again on a declining pressure profile. My distribution is good enough not to show any obvious uneven pour or channeling defects with a naked PF and VST basket.

My result is not measured with refractometry yet but it is a higher than normal yield which in the past I’ve measured at between 19 and 22%. I definitely start to get flavours that are not so good: roasty, old musty leather, sweaty....

I’m not sure what to make of this. Is Rasmus’ experience further proof of the superiority of very large flat burrs?

[dsc]

I can achieve something like ‘blooming’ with a Vesuvius. (I use a Ceado E92 conical grinder.)

I use a 15 second 2 bar preinfusion then drop the lever half way, which keeps the pressure in the group without building on it. After 20 or so seconds I start the pump again on a declining pressure profile. My distribution is good enough not to show any obvious uneven pour or channeling defects with a naked PF and VST basket.

My result is not measured with refractometry yet but it is a higher than normal yield which in the past I’ve measured at between 19 and 22%. I definitely start to get flavours that are not so good: roasty, old musty leather, sweaty....

I’m not sure what to make of this. Is Rasmus’ experience further proof of the superiority of very large flat burrs?

Imho EKs are going to extract differently for whatever reason and higher EYs with EKs still taste good, whereas this is not necessarily true for conicals. Perhaps if you were to compare both with darker roasts conics might be better, but for lighter stuff I think anything above 22% on the conic is not going to be uber tasty.

We are probably getting slightly out of topic here, but I'll just quickly add that if you want to bump EY even more you can single dose the E92 and very very slowly feed beans which will allow you to grind way finer.

T.

[Obnic]

Imho EKs are going to extract differently for whatever reason and higher EYs with EKs still taste good, whereas this is not necessarily true for conicals. Perhaps if you were to compare both with darker roasts conics might be better, but for lighter stuff I think anything above 22% on the conic is not going to be uber tasty.

We are probably getting slightly out of topic here, but I'll just quickly add that if you want to bump EY even more you can single dose the E92 and very very slowly feed beans which will allow you to grind way finer.

T.

That certainly resonates with my recent attempts.


Need someone with a monolith and a DE1 Pro to run some tests

[decent_espresso]

leak_2.jpg

Decent customer Brandon posted a message a few days ago that the GFI interrupter on his electric plug was tripping. He noticed a little bit of water coming out the left side of the espresso machine.

I'm glad the GFI was tripping, because that's exactly what the safety systems are supposed to do when there is a leak.

Brandon then opened up the espresso machine, saw that the water drip was due to a small leak when the machine was under pressure, and he followed the water trail through a hole on the bottom of the chassis. That hole is there as part of UL safety compliance.

We specifically made the machine drip water out the sides, instead of on the bottom, so that any water leak like this would be very noticeable by customers. When something fails, a good design is one where it fails extremely visibly.

At any rate, we know what the cause of the problem is. The majority of the machines we have shipped include a 3D printed 180° bend reinforcement. However, I had argued that this was no longer needed because the Teflon tubes, once they have been bent for a long time, stay in shape. My engineer Johnny was not in agreement. A few machines went out without this reinforcement, and one has leaked now. So, Johnny was right.

We are sending Brandon a free replacement assembly, complete with tube, reinforcement and O-rings (photo of care package below). My engineers also extracted the relevant sections from our in-house assembly manual and I posted that to the discussion.

FYI All this discussion happened publicly on our owner's forum, with all 300 other decent espresso customers being able to read everything. The hope is that by being transparent about problems and how we deal with them, that people will have greater trust in us.

-john

[decent_espresso]

portafilter_placing copy.jpg

Because our espresso machine design has an extra handle on the group head, for me it’s really important that the portafilter lines juuuuuust right on the group head, once it’s locked in.

I’m obviously not the only one who notices this, as photos of this alignment appear frequently on social media (two examples below).

Getting this fit right is really finicky, because it’s down to tenths-of-a-millimeter tolerances, as you’re slowly tightening something against a rubber gasket.

The way we accomplish this perfect alignment is by using precision cut fiberglass insulators. We order them in a variety of thicknesses, and then we figure out—by actually assembling them— which works best. A computer CAD model can’t do the job.

Our v1.1 group head parts have changed, because we removed 4mm of headspace above the basket in an effort to dry the puck to help make it easy to knock out, after an espresso.

So…. in the photo below, you can see the steps my engineers have taken over the past week, to get the alignment just right, again, with this latest espresso machine version that we’re about to ship.

-john

screen 2018-10-09 at 11.45.28 AM.jpg screen 2018-10-09 at 11.45.03 AM.jpg

[tohenk2]

Hmm. I bought alle basket sizes Descent offers (2 sets, 1 for myself, 1 for my daughter) with some analog thermometers.

The thermometers are nice, the shape prevent them from rolling away .

At present I can get good ristrettos from other baskets (IMS, IMS the Single, IMS precision, VST and La Marzocco) and I find I need to grind way finer for this with the Descent 10gram basket.
Should be no problem ... I have plenty room to go finer at my Macap M4D. But! <Third world luxury problem> I'm single dosing the M4D and if I go much finer the beans start backing up in stead of going through. Since I'm also waiting for the Niche Zero I don't want to put the hopper back on.

One other thing - is a 58.4mm tamper ideal for these baskets?

[decent_espresso]

One other thing - is a 58.4mm tamper ideal for these baskets?

For the 10 g basket, I definitely recommend a 58.4 mm tamper, not larger. For 15 g and larger baskets you can get away with a 58.5 mm tamper.

Our version two tampers average at ~58.45 mm, and I am measuring samples here as being between 58.42 mm and 58.47 mm.

I heard from a client a few days ago that their VST 58.5 mm tamper was jamming in our 10 g basket. The smaller size of that basket means the taper starts earlier and that can cause a problem.

– John

[decent_espresso]

A few weeks ago I put a new system in place for keeping track of each customer who had a problem with one of their espresso machines.

Quite a few people at Decent Espresso get involved when a customer has a problem, so I decided to use the basecamp forum software to manage it. We now make each new customer problem into a Basecamp to-do item, which only gets completed once everything is okay with that customer.

Two recent events precipitated my formalizing how we handle repairs:

1) we now have a special low-cost return rate with UPS, so that we can organize for an espresso machine pick up from the customer's location and send it back to Hong Kong for our cost of only $70. Since we offer a two-year warranty, we pay for this.

2) Back in Hong Kong, We keep a stock of refurbished machines and we send one of these to a customer immediately when there is a problem that requires a repair. It usually takes 48 hours for the replacement machine to arrive with the customer. This way, we don't make the customer wait while the repair happens: ideally, they don't go without caffeine for more than a few days. :-)

For those that are curious, here is a PDF of the complete conversation about Lars' problem and how we resolved it.
http://magnatune.com/p/lars.pdf

In this particular case, a capacitor on the AC power board blew. Ray worried that there might be a design flaw in his schematic, so some extra conversation around that ensued with Parry who had done the repair. In the end, we didn't see a design flaw, and as this is the first time this particular problem has occurred, we will log it and watch to see if it recurs.

There are two positive outcomes to this new approach we are taking to repairs:

1) no matter where you are in the world, we now have an efficient way to swap the machine out and get you a replacement very quickly. We no longer need you to post your machine to a repairman in your country.

2) Each problem that a customer has is now discussed among all of us, including the engineers responsible for the design so that the possibility of improving our design to prevent problems is greatly facilitated. If the same problem occurs several times, that should be very visible to us.

-john

[o2c]

You ended it with a cliffhanger. Did the cleaning cycle sufficiently restore the parts?

[decent_espresso]

You ended it with a cliffhanger. Did the cleaning cycle sufficiently restore the parts?

The stainless steel comes out perfect, but even with Cafiza, once coffee starts being made using our brass parts, they will always end up being slightly discolored, even after cleaning.

Here's what Lars' brass and stainless steel parts look like after 24 hours in Cafiza:

preview-full-image.jpg preview-full-image-1.jpg

Obviously, the brass no longer looks new, but to me this is acceptable as a refurbished machine.

We've had long discussions about our brass alloys, including with a metallurgist who is DE1+ customer. Given that we CNC our brass parts, we don't think we can do better with the guaranteed food safety that we require.

-john