Need hints on using E61 thermocouple adapter

[ElBean]

Hi all,

My first post here. I would appreciate help with the following:
I installed Eric's adapter in my Vetrano over a year ago connected to a PID.
After long warm up, first flush reading starts to decline about 1 deg/sec to about 207 and then speeds up down hill.
It is almost impossible to stop the flush right at 206.
Also, how long it should take for temp to come up for second pull.
My boiler is set at 1.2 and the pump at 9 bar. 123-124 volts constant power.

thanks,

Elan

[HB]

It is almost impossible to stop the flush right at 206.

Depending on the probe placement and the speed of your thermometer readout, the transition point between boiling and near-brew temperature water will be somewhere between 207 and 204. Assuming you follow the "flush and rebound" technique documented in HX Love, start by observing the thermcouple readout and the end of the water dance. That's the transition point, which is typically around 206F, but could be a couple degrees higher or lower. Once you know the transition point, you can accurately reproduce the same brew temperature by flushing to the same point past the transition point, either by time or if you're thermometer's readout is fast enough, by the thermometer.

I recommend a "warm up" flush if your Vetrano has been idle for awhile. Otherwise the reading tends to spike and fall too quickly. For example, flush to your target temperature, wait a couple minutes... flush again to your target temperature, rebound, then start the extraction.

Also, how long it should take for temp to come up for second pull.

I would have to check my notes to be certain, but around two minutes sounds right. Much faster than that and it's easy to overflush.

[erics]

Elan -

I happen to have a Vetrano in my basement (labooraatory) as I type and have been pulling thermofilter shots on it for the past month in all sorts of situations.

Flushing to 206 won't "cut it." - you need to go to around 198-199 to hit a 200 F shot assuming you pull the shot within 10 seconds of stopping the flush. I know EXACTLY what you mean when you say how difficult it is to hit a specific flush temp.

As you can imagine, there are several ways in which to pull a shot on Vetrano, or Anita, or Andreja, or . . . utilizing either the thermocouple adaptor or the digital thermometer and much depends on YOUR particular modus operandi. I will be more than happy to post a flush & shot temp chart based on YOUR idle grouphead temps with or w/o PF in GH.

[Kuban111]

Hi Eric,

I'm a new vetrano owner & I also would be interested in that chart.
On my vetrano at home my idle time is 210 / 211 with the portafilter on the gh.
I haven't changed anything, still set up the way Chris' coffee sends out the machine.
Press 1.2 at 9bars

I just picked my machine up with the adapter and I'm new to hx flush.
coming from an Isomac Venus.

Please let me know if this sounds right.
I flush to get to 197 then wipe the gh load & lock the PF.
That's been my normal shot procedure.

Sure will appreciate any suggestions from anyone willing to help a new hx owner.

Thanks all.
Michael

[erics]

Greetings Michael -

Sounds like a perfect plan to me although, as you have maybe found out, it is tough on Vetrano to flush to a specific temperature. Next step would be to try 196.5 or 197.5 and see if you can discern a difference while keeping everything else as consistent as is reasonably possible.

What you are doing reads like a "flush-n-go" technique, depending on the amount of time between ending the flush and starting the shot. Below is another way of accomplishing the same thing showing the differences between Anita and Vetrano with the same thermocouple and the same instrumentation:




I set up Vetrano and Anita as close as I could and flushed both to essentially the same temperature (I got lucky with that). Note how Vetrano hits the target 4-5 seconds before Anita because of her slightly higher flushing flowrate and lower flushing water temperature. This method would be termed a flush-n-wait method BUT if you start grinding at the same time you start flushing, you would be amazed as to how the times meet together at the most opportune time.

Edit - added the graph and explanation below. This is a thermofilter shot on Anita after flushing to 197 (196.7) and pausing for 10-11 seconds before pulling the shot. I started the flush with the same GH temperature as the previous Anita graph - maybe a couple of tenths higher. I suspect Vetrano would be very similar but not necessarily identical. In any event, the two methods, which I consider to be 180 degrees apart, produce similar results. Using the flush-n-pause-n-go method, you are using the group to heat the flowing brew water whereas in the flush-n-wait method, you are using the group to cool the flowing brew water.

[RegulatorJohnson]

i have a vetrano and erics adaptor.

i recently have been re-visiting the back-flush cooling flush.

it seems like i get a more accurate reading this way because by the time the display reads 200° that water has passed and i really have something probably cooler. if i backflush i can simulate a shot which is what these machines are meant to do... make shots. not flush 6-8 ounces of water.

i do this until the pump hits full pressure then +3 seconds. wait 10 seconds and repeat until the temp, when the pump hits full pressure, is 4° above where i want the brew temp to be... ie 202° will yield a 198° brew temp. then i can brew immediately or up to about 30 seconds and get that temp. a quick normal flush to verify the temp will work as well.

the temps seem to be more stable. than a traditional flush.

i only use the back flush on the first shot after a long idle. but it will work for any shot.

thanks for the time.

jon

[mgwolf]

Jon,
Could you describe in more detail what a backward flush technique is? Thx. Michael

[ElBean]

Interesting, Jon, but what do you mean "i do this until the pump hits full pressure"?
My pump is at full pressure as soon as I raise the lever.


Tx

Elan

[CyclingCraig]

Thanks Eric for the work and research

But I now have a question, the Vetrano and the Anita (What I Have). Use the same Boiler and Group Head, is that correct?

If that assumption is correct, then why does the Vetrano recover MUCH faster than Anita, also why is the inital rebound after flush is stopped much higher than anita?

If I flush my Anita to 185 I would be waiting around for at least 3:30 to 4:00 for my group head adapter to read 198? I flush to 193 reading on thermometer adapter, Build my shot and pull about 2 - 2:30 min later where then temp reads 198 - 198.5. My Upgrade Jaeger PSTAT is set to 1.1 bar.. could that have such a big effect on recover time compared to the 1.2 setting?

[RegulatorJohnson]

Interesting, Jon, but what do you mean "i do this until the pump hits full pressure"?
My pump is at full pressure as soon as I raise the lever.

mine will show 8 bar with nothing in the group.

then with a shot or blind filter the pressure will say 8bar then it will go to 9 bar when the pre-infusion is over. that is what i mean by hitting full pressure. watch your gauge. unless i am mistaken this is the e61 pre-infusion happening. after a few seconds, you can hear the pump go under load. the pump sound changes, wait 2-3 seconds and stop the pump. wait 10-15 seconds do it again.

this is done with a blind PF disc in the basket so i can use the same PF for the shot.

vitals on my vetrano.
pstat - .9 - 1.2 bar
main lines pressure - 3.5bar (unless some one re-fills the washing machine 2bar, even with regulator installed)
brew pressure 9 bar
group temp at long idle 45-60 minutes - 210°


basically using erics chart and the fact of the 4° difference between the probe and the puck. i can PRETEND to do a shot see its temp on the probe, subtract 4 and know the shot temp. since there really isnt a shot in there i can abort the pretend flush-shot and pretend to make another shot until i can see the machine is at the proper temp.

this is similar but different to making 2-3 shots just to dump them. these shots were sacrificial just to cool the machine.

the machine is built to make shots without flushing unless it sits for too long so you have to pretend you pulled some shots.

i wish i could explain this better. anyone want to come on over?

jon

[erics]

But I now have a question, the Vetrano and the Anita (What I Have). Use the same Boiler and Group Head, is that correct?

Vetrano has an additional pair of 1/8" elbows in the top hx line (for sure) and the lower hx line has an additional inch in overall length (I think). Other than that, boiler and group are identical.

If that assumption is correct, then why does the Vetrano recover MUCH faster than Anita, also why is the inital rebound after flush is stopped much higher than anita?

Recovery differential in this particular test run was 22 seconds favoring Vetrano. I don't have a good answer except that this was one test. Maybe Anita is tired

If I flush my Anita to 185 I would be waiting around for at least 3:30 to 4:00 for my group head adapter to read 198? I flush to 193 reading on thermometer adapter, Build my shot and pull about 2 - 2:30 min later where then temp reads 198 - 198.5. My Upgrade Jaeger PSTAT is set to 1.1 bar.. could that have such a big effect on recover time compared to the 1.2 setting?

Yes, there is a difference.

[erics]

Here are graphs of two shots pulled in two completely different ways yet achieve almost identical temperature results. The first graph shows grouphead temperature and thermofilter temperature of a shot after flushing to around 183 F and waiting for the group to hit 197 F. The group is being used to cool the incoming brew water.

While it is not shown, it took Vetrano 2.5 minutes from the start of the flush before he was ready to pull the shot. Those 2.5 minutes can be used to grind, WDT, distribute, level, and tamp the basket - at least that is what I do, thus you are doing "things" concurrently rather than consecutively.

The second graph represents a shot pulled after flushing the group till the meter read 199 F, pausing for 10 seconds, and then immediately starting the shot. The group is being used to heat the incoming brew water.


I also did a Shot 29 (not shown) which was used to mentally adjust the "flush to" temperature for the graph shown above in order to intentionally match the first graph. All flushing was started with the same grouphead temperature of 212 F and, of course, the Microsoft Excel files are available for the asking. Email - erics@erols.com

[jeffg]

i have a vetrano and erics adaptor.

i recently have been re-visiting the back-flush cooling flush.

it seems like i get a more accurate reading this way because by the time the display reads 200° that water has passed and i really have something probably cooler. if i backflush i can simulate a shot which is what these machines are meant to do... make shots. not flush 6-8 ounces of water.

i do this until the pump hits full pressure then +3 seconds. wait 10 seconds and repeat until the temp, when the pump hits full pressure, is 4° above where i want the brew temp to be... ie 202° will yield a 198° brew temp. then i can brew immediately or up to about 30 seconds and get that temp. a quick normal flush to verify the temp will work as well.

the temps seem to be more stable. than a traditional flush.

i only use the back flush on the first shot after a long idle. but it will work for any shot.

thanks for the time.

jon

From what I am seeing this has GREATLY simplified my finding the target temp, thanks! I believe this should be somewhat hailed as the best method not only that but I must use spring water in my machine and this is saving me a massive amount of water. Before Johnson's above method my reading were all over the place and i was majorly confused but this method allows you to simply drop the temp by a few degrees each blind flush, you hit the target temp and done.. no more guesswork for me, I need all the help I can get

[RegulatorJohnson]

i also came across it while using the pulser and the tank. it seemed to save water for me also. but not as much of an issue on the plumbed vetrano.

maybe i should have called it the "simulated shot" instead of the "backflush cooling flush" ?

im glad its working for you.

jon

[jesawdy]

i recently have been re-visiting the back-flush cooling flush.

it seems like i get a more accurate reading this way because by the time the display reads 200° that water has passed and i really have something probably cooler. if i backflush i can simulate a shot which is what these machines are meant to do... make shots. not flush 6-8 ounces of water.

i do this until the pump hits full pressure then +3 seconds. wait 10 seconds and repeat until the temp, when the pump hits full pressure, is 4° above where i want the brew temp to be... ie 202° will yield a 198° brew temp. then i can brew immediately or up to about 30 seconds and get that temp. a quick normal flush to verify the temp will work as well.

the temps seem to be more stable. than a traditional flush.

i only use the back flush on the first shot after a long idle. but it will work for any shot.

maybe i should have called it the "simulated shot" instead of the "backflush cooling flush" ?

Interesting...

I mucked with this idea (a few months ago) when temp surfing the Quick Mill Alexia to save on water. I'd backflush a few times until I forced the boiler heater light on. It seemed to work, but I never sold myself on how consistent it was.

When you 'flush" against the blind, the only way you affect the temperature is by the mixing of cool incoming water and hot water in the HX (Vetrano. et. al) or the boiler (Alexia) via the OPV. I wouldn't expect it to have much affect on the overall E61 grouphead temp, just the water contents.

I'd be curious if other people have success with this method (Eric? You always seem to a be a glutton for datalogging punishment ).

[Ozark_61]

Eric - great work on all the data there. Gee... sure would be nice to have data logging capability! FWIW, you might want to try to extend your 10 sec wait after the flush a little bit and see if the temp will be more stable through the shot - and then you can compare the taste to see if it matters or not.

It is very interesting to see that different implementations of the e61 gh can have quite different results in temp stability / reliability via the original posters comments about the Vetrano.

Geoff

[RegulatorJohnson]

I'd be curious if other people have success with this method (Eric? You always seem to a be a glutton for datalogging punishment ).

eric did some data logging for me. this chart shows the p-stat at 1.03-1.19bar my actual setting here is .9-1.1 so i am running slightly cooler than this chart.



in full disclosure. eric has requested that i let everyone know i do a initial "normal" flush to the point when bubbling stops. then i do simulated shots to dial in the temp i want. for me at 4500ft in SLC ut water boils at 204°F so i know i am pretty close.

jon

[HB]

maybe i should have called it the "simulated shot" instead of the "backflush cooling flush" ?

I tried this technique on the Vibiemme Domobar Super and it works very well! The "blind flush" drops the temperature more slowly than an unimpeded flush, which plays to the strengths of a E61 thermometer adapter versus the thermocouple adapter. Less water in the driptray, less refilling and emptying.

As the unofficial keeper of heat exchanger nomenclature, the techniques to-date are:

• Flush and rebound - from the original HX Love article, a flush followed by a 30-45 second wait while the heat exchanger recovers.
• Flush and go - for fast recovery HX machines, this is a flush followed by the extraction within 10 seconds.
• Flush and wait - Eric's flush to well below the target temperature, then waiting for the thermosyphon to re-establish itself until the thermometer adapter reading matches the desired brew temperature.
• Blind flush - Jon's "flush until you're close, and then flush with blind basket" approach above; requires Eric's thermometer/thermocouple adapter.

I believe the particulars of Jon's approach will vary from machine-to-machine because of the tuning of the return versus direct flow from the thermosyphon during an extraction. That is, the water reaching the brewhead isn't only from one leg of the circuit:



Although this diagram depicts a one-way street, there's no shutoff solenoid blocking the return (blue) leg during an extraction, so the water reaching the group will be a mixture of the water that's passed by way of the heat exchanger (red) and some that's pass through the return (blue) leg. If I understand correctly what's happening, Jon's "blind flush" is forcing the water to rapidly circulate, thereby equalizing the system's thermal balance without expending water. Neat idea, Jon!

[avdiscolo]

I just installed Chris Coffee's grouphead thermometer and have tried the "blind flush" method on my Anita for the last two days, and I think it works great too. It's the perfect technique for someone who doesn't like to waste a lot of water and who doesn't like to wait a long time for their shots.

I have a couple of questions:

1. When performing the "blind flush", the temperature is changing constantly when the pump is at full pressure. If I don't see 202-204 degrees after 3 seconds of full pressure, I stop and wait 10 seconds and try again. Once I see 202-204 degrees and then a temperature "downtick", I stop the pump and wait for the idle temperature to reach 196-198 degrees and then start the shot immediately: I've found that Stumptown Hairbender seems to taste better around 196 and Vivace Vita seems to taste better at 198 degrees. Is this idle temperature relevant, or am I imagining things?

2. Will the extra backflushing cause premature wear on the pump or other parts? Is it bad to run the pump during a backflush at full pressure for more than a few seconds?

Thanks everyone for sharing this information.

Anthony

[ElBean]

Since starting this thread, I got lots of info and charts from Eric. Not being able to duplicate or come close to his protocol, I suspected that incoming water temp might be a factor.

The household water comes from my own 400 ft deep well....fantastic quality, but very chilly.

When I lived in S Florida, city water temp was in the 80s and water from a tank inside a non plumbed machine is much hotter.

If this makes any sense, I can tee off the instant hot water dispenser (195 deg) and mix it with the cold water to get more manageable incoming water temps.

Any thoughts?

Thanks,

Elan