Need hints on using E61 thermocouple adapter

Beginner and pro baristas share tips and tricks for making espresso.

#1: Post by 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.



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#2: Post by HB »

Elbean wrote: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.
Elbean wrote: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.
Dan Kehn

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#3: Post by 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.

Eric S.
E-mail: erics at rcn dot com

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#4: Post by 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.
"azuca, azuca" Celia Cruz

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#5: Post by 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.

Eric S.
E-mail: erics at rcn dot com

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#6: Post by 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.

2012 BGA SW region rep. Roaster@cognoscenti LA

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#7: Post by mgwolf »

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

ElBean (original poster)

#8: Post by ElBean (original poster) »

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.



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#9: Post by 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?

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#10: Post by RegulatorJohnson »

ElBean wrote: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?

2012 BGA SW region rep. Roaster@cognoscenti LA