One for @"DavecUK"#1 I suspect. Thanking all contributors in advance. I'm establishing a "grinder lab" to compare burr sets side by side. An important part I have two Puristka's equipped with Geisinger temperate probes in the group heads. I'll upload a video in a new post below, but in the meantime my challenge is to how to complete simulatenous pours one the two macines and have the temperature to within one degree through the group head on each machine. This is more challenging with a machine with a small boiler because the window of stable temperature is limied. You'll see in the video below and the temperature through the group head, as measured by the Geisinger probes, initially riases and then falls dramatically, presumably as the heated water in the boiler is replaced with water from the external resevoir. My question is: whats the best method for having both machines pour the espresso as close as possible to thesame temperature? Note: I only need to do one pour per day simultaneoulsy on both bachines, not back to back pours.

Here's the video, in case that helps. https://youtu.be/hseUXhnTNfM

Your video is a "frozen" photo 😊…edit…it was only a temporary issue with the video loading or else, anyway now is ok. OPV at same setting, push the pump button without to move the lever until the OPV will discharge, so you will fill the boilers at almost the same level, of course all the PID parameters must be the same, wait at least 1 hour before the first shot so you are sure that the whole system has got a stabilized temp. I did follow such simple method with my Carola, and for me was ok to reach a quite stable condition for subsequent test, but i never compared 2 of it, anyway the Carola has a different thermosyphon path, so maybe it could differ in the behaviors.

What's it like with coffee in the pf? Any slower to swing?

> @"giampiero"#p42678 push the pump button without to move the lever until the OPV will discharge, so you will fill the boilers at almost the same level The brew boiler is always full.

@"giampiero"#p42678 oh that sounds promising. Nothing like the voice of experience Thank you! PS I accidentally uploaded a photo instead of the video, I edited it quick smart but you may have been the victim of my initial e-tardness.

@"Cuprajake"#p42680 temperature swing? good point. very good point. will check it tomorrow and reshoot the video. thanks for the idea. It could slow the fluctuation down.

Yeah possible., How much did you flush through in the vid? I know it's not an hx so not sure if a flush applies, on my old hx I would flush till the temp peaked. Then pull a shot,

But really you shouldn't have too. @"Beverast"#66 has one of these I'm sure And @"DavecUK"#1 maybe a better pid setting?

Would there be a difference when water is just free to run through, vs pressurised ? In the former, the heat is being taken straight out, whereas in the latter (usual brew) there's a much slower actual flow and added backpressure that could mean the heat loss is much less.

@"mobius"#p42694 Yeah I would make that assumption as well. I have not done tests with external thermometers on my Puristika but under pressure the shots always come out nice and hot…usually have to let the brew cool for around minute or so before I can drink it. Would be good to see what the readings are with the pressure.

ECM Puristika temperature challenge

tompoland

Not posting this for any other reason than to give myself the disciple of measuring as many days as I need to come to a reasonably firm conclusion about what I should set the PID to and how long after start up to run the comparision pours.

No comments required, all comments welcomed.

Todays results, 45 minutes after start up and using just the one grinder.

I will keep running these comparisons until I’m a bit clearer on the pattern but at this stage it seems that the pouring temperate is running, on average, approximately 2 degrees hotter than I want i.e. the PID is set to 93 but I see a range mostly between 94.5 and 95.5 coming through the group head. I won’t change anything just yet but I’m inclined to dropping the PID to 91 if that continues.

DavecUK

tompoland Remember the group head thermometer will read 2-3 degrees hotter than the water entering the basket.

tompoland

DavecUK oh really? Did not know that!

I’m almost beginning to think that maybe I shouldn’t be second guessing ECM.

But really, who could have known that they knew more about designing espresso machines than me?

I mean, no one could have seen that one coming 😁

(Thanks again).

DavecUK

tompoland I think they might be using my Puristika recommended settings, they sent me the machine to get an engineering review in 2019 (pre covid) a few years before it launched. The launch was delayed due to Covid.

mobius

@tompoland I watched James Hoffman’s latest video last night, about the Faema, and it resonated strongly with this thread for me 😄

tompoland

mobius ha … pretty interesting video though. Must say I cringed a bit to see all the tech on it 🤔

tompoland

DavecUK I had wondered if you were involved. It’s a cracker little machine. Quite a feat of engineering packing such high quality kit in such a small footprint. Congrats on the result and thank you.

DavecUK

tompoland I had wondered if you were involved. It’s a cracker little machine. Quite a feat of engineering packing such high quality kit in such a small footprint. Congrats on the result and thank you.

I also did a modification on mine, which couldn’t really be done on production machines. So I can use mine to manage/profile pressure, but I advised then that the expansion valve should really only be used to limit max pressure and profiling done with a paddle valve on the group…..giving ultimate versatility. It is a really nice machine though.

tompoland

DavecUK a paddle on the group with an temperature gauge would be pretty special.

For my purposes in the “grinder comparison lab” I won’t need a flow control paddle however. The idea is to have something that is more like what the average punter would have at home, hence the E61 choice.

DavecUK

tompoland It’s a great machine for that kind of usage.

During Duo testing I used mine. Although I had to test on 6 different machine types.

tompoland

DavecUK intersting. so I’m clear, you tested using the Duo with six different models of espresso machines or sixe different types of machines e.g. boiler vs heat exchange vs direct lever etc?

either way, that’s quite extensive.

DavecUK

tompoland intersting. so I’m clear, you tested using the Duo with six different models of espresso machines or sixe different types of machines e.g. boiler vs heat exchange vs direct lever etc?

I tested with different types of machine:

HX
Pressure profiling (Auto)
Pressure profiling Paddle
Vibration pump
Vibration pump with profiling using thermoblock
Standard Dual Boiler- no profile
E61 non E61

I was testing for well over a year…many, many prototypes were produced with each iteration being improved and tweaked, as the design was modified..I don’t think people realise this grinder existed for over 14 months!!

P.S. I couldn’t check much with a Lever, because I don ’t have a working lever, just the old scrap Alpha, hence why Jake was testing, also he had an 83mm Mazzer Major, so another good comparison….aaaand he is known to be very picky!! 😁

tompoland

Quite amazing. Tx for the insights.

« Previous Page Next Page »