Well that will be interesting as Jepy designed and built such a system several years ago, and there have been others.

-Greg

tekomino wrote:I think that trying to replicate temperature between machines in different places is futile because of environmental factors alone.

+1.

tekomino wrote:More important thing is repeatability of temperature/profile on same machine and that is what I would call temperature stability. If temperature profile on a given machine can be reliably repeated I think you can say you have temperature stability.

It can be bloody difficult when the temperature rises 15°F during the day and the airflow changes from a breath through an open light to nil to forced aircon.

Temperature measurements tell almost nothing about machine performance. The current boiler offset fad on e61 DBs is sheer lunacy. Temperature profile varies with the shot. Only taste can instruct whether to change temperature and / or grind and / or dose and / or time.

Note to Greg : youse outta have a high Cv valve option on the Scace...
http://www.swagelok.com/downloads/WebCa...01-142.pdf

Hi there:

I've made (and will make on a custom basis) Scace 2s with Swagelok's excellent needle valve with micrometer head. It's expensive and requires shortening in order to gain acceptable cup clearance, but it's very repeatable. Unfortunately it's in the camp of things like electronic pressure transducers - prohibitively expensive for most, but useful for certain subsets of the coffee world.

-Greg

1st-line wrote:In other words, for those seeking. . . superior temp stability, you 'may' not be able to achieve the same exact results as your neighbor next door with the same machine.
[Do] . . .others have a difficult time replicating results posted by others online and what is believed to cause the different impact in layman's terms[?] .

Jim P's thread-starting comments seem relevant because I am less inclined toward modding and experimenting and more interested in buying machines "off the shelf," and then achieving from them the manufacturer's intended results. A bonus with these machines would be to have a higher degree of confidence when sharing impressions of coffees and profiles across distances larger than a kitchen.

So, specifically, what's up with this?:
The Dalla Corte espresso machines can be controlled through either an online control system or a digital control system. All machine parameters are programmable and usages and inventory control can be remotely monitored. Perfect for businesses with multiple cafés or remote management.
http://www.ausbeverage.com.au/dalla-corte.php

And generally Where might similar and expanded technology go to enhance the feeble word-processing and primitive data sharing that enthusiasts now use to communicate near-real-time shot results? Think in terms of 2, 5, 7 years down the line.

Hi Jim:

I'm gonna try to answer within the body of your text.

1st-line wrote:Hi All,

I do really appreciate the effort the HB community puts forward in actively participating in finding solutions and improvements for the betterment of the espresso machine user and managing one of the parameters (temperature stability) to repeat the desired holy grail, especially with regards to temperature stability.

I would like to 'chime in' on one important factor from the business side and the technical side. Although I am making a general and bold statement, I do want espresso machine owners to realize that I have not found the holy grail to perfect temperature stability on many espresso machines for every usage scenario.

My definition of the holy grail of temperature reproducibility is the following:

1) A barista ought to be able to walk up to an espresso machine and brew an espresso under any duty cycle condition with the expectation that the brewing temperature and profile will fall within a reasonable window without having to perform any duty cycle-dependent group flushing, chicken choking, hocus-pocus whatever.
2) A reasonable window is defined as a brewing temperature range small enough that variation in temperature is insignificant when compared to other parameters affecting shot-to-shot variability in taste.

1st-line wrote: I have tested many machines (including ones we do not sell) under $3k using a data logger that records temperature stability across 16 different thermocouples cemented to 16 different locations with recordings up to 1/100th per second in each thermocouple. This data logger had cost close to $4k and is actually used in some nuclear power facilities to monitor temperature.

I have even tried to replicate results of what I have found online, have tried different testing scenarios/procedures, and I have difficulty replicating a lot of those results. In some cases, customers have emailed me results that seemed perfect using different tools on machines they bought from us, and I had still a difficult time replicating. In different words, I will find a usage pattern or lack of a pattern to find a delta in any machines capability in managing temperature stability on any espresso machine. I have even changed variables to find the delta (ie drafts, ambient temps, voltage, etc).

This doesn't surprise me too much. Different methodology, location of measurements, measuring equipment, test conditions, method of analysis can affect the answer. Duty cycle is a big issue in espresso brew temperature, so comparisons have to be done using a common method. The method used for WBC machine evaluation is useful to put methodology on an equal footing. Location of measurements is a biggie when measuring temperature. For example, there's a big difference between measurements performed on the outside of a boiler compared to the inside for reasons including proximity to the heat source (element), thermal resistance of the boiler wall, thermal resistance of scale, height of water within the boiler, and others. Most of the folks performing measurements on their own do not check the accuracy of their equipment. Fortunately, this can be done fairly easily and the methodology has been posted on HB in the past. Test conditions are a big problem for many machines. Variability in boiler pressure within HX machines means variability in temperature within the boiler. This translates to machine-to-machine variability in thermosyphon loop behavior for machines using such schemes. While it might seem a simple matter to adjust two boilers to the same pressure, actual gauge-to-gauge consistency for the quality of gauges used for this purpose is pretty poor, on the level of 10% uncertainty, meaning that setting up identical test conditions can be challenging. Variability in water level as set by the level probe may affect the amount of hx immersed in liquid compared to gas, and certainly affects the amount of available heat contained within the boiler. Both of these factors affect the rate of heat transfer to the brew water, and further affect machine-to-machine variability. The amount of heat transferred to the room environment from an e-61-style group is dependent on the temperature of the room, so environmental conditions are also a strong factor. These effects have been discussed on coffeed to some detail, as commercial environments exhibit seasonal and traffic-related variation. Method of analysis can affect the answer. Using the very last temperature value in a series of measurements is very different from making an average of readings over the duration of the shot. And blindly taking an average that includes temperature ramping that occurs when the pump is activated gives a very different answer compared to an average that ignores the first several seconds of extraction. Once again, adherence to a common method, such as the still-current WBC method, will help.

1st-line wrote: The reason for my post is that there are sometimes posts about design flaws or defect with a(ny) machine because of a delta in temperature in a certain scenario. From the business side, it is not a flaw or defect.... If a reseller or manufacturer explicitly stated a certain performance of temperature stability without any statement that results could differ, then I would agree that there is false advertising, a design flaw, and/or a defect. However, manufacturers design different espresso machines at different price points which include different designs and features that accentuate different results with regards to the 'resulting' performance of an espresso machine. One of those results being temperature stability.

This is absolutely correct, IMV. We're not talking high-volume production here, and it currently is pretty expensive to produce a machine that approaches my definition of holy-grail temperature reproducibility. On the other hand, I still challenge manufacturers to get off their butts and do some engineering instead of recycling generic components. Many of these components are very old designs with inherent problems that could be eliminated with some work.

1st-line wrote: This post is not to create any controversy, but MAINLY to just keep a level understanding of what and how manufacturers offer at each price point when researching, designing, and producing their machines. In other words, for those seeking a double boiler machine or other styled machine for superior temp stability, you 'may' not be able to achieve the same exact results as your neighbor next door with the same machine.

The secondary purpose of the post is to find out if others have a difficult time replicating results posted by others online and what is believed to cause the different impact in layman's terms. As you can see, I am not pointing any fingers to any particular machines and I hope followup posts remain the same as we nor any poster should disparage any machine in the marketplace. In other words, I would like to not to be machine specific but am looking for members who have had recorded different results from they see online posted by others.



Finally, keep up the good work on HB as many topics have been quite an enjoyable read.

The reasons I listed as variability sources should illustrate why different people report different answers. Hope I made sense.

-Greg

Martin wrote:So, specifically, what's up with this?:
The Dalla Corte espresso machines can be controlled through either an online control system or a digital control system. All machine parameters are programmable and usages and inventory control can be remotely monitored. Perfect for businesses with multiple cafés or remote management.
http://www.ausbeverage.com.au/dalla-corte.php

Advertising BS? doesn't tell you much about the performance of the machine, does it.

This sounds like a standard telemetry system. This is on a few analytical machines in my lab and it allows the manufacturer to remote diagnose problems or update firmware. Some machines even order their own consumables. The device is given its own website and can be accessed anywhere in the world. This can also be used for control of the machine or look up its usage history by the operators at a remote location. DC's implementation is aimed at professional coffee chains, but who knows, with the right sensors and some wifi or CAT5 cable would let you beam your exact parameters to anyone else to replicate in future incarnations.

No thanks
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kmills wrote: DC's implementation is aimed at professional coffee chains, but who knows, with the right sensors and some wifi or CAT5 cable would let you beam your exact parameters to anyone else to replicate in future incarnations.

This is fascinating stuff. Maybe a way out of that 20th Century rut of one-more-mod, one-extra-tweak. Seems to have enormous potential for melding real-time and -use consumer cupping and non-stop training. I give it ?? 5 years. --faster if HB'ers get involved.