What's the best way to use Eric's E61 thermometer adaptor?

[Beezer]

I just received the digital thermometer adaptor from Eric S, which installed easily into my Anita. Now I'm trying to learn the best way to use the thermometer to improve my shots.

Before receiving the adaptor, I'd been flushing about six seconds past the flash, then waiting 15 or 20 seconds and pulling my shot. With the adaptor, I can see that the group temperature is about 198 degrees when I stop the flush, and goes up to about 200 degrees by the time I pull my shot. So far so good. But then the temperature drops steadily during the shot, sometimes all the way down to 191 or so. What gives? I thought the temperature on an E-61 machine stays pretty stable throughout the shot. By the way, the boiler is set to 1 bar and I allow at least half an hour for the machine to warm up.

I also tried flushing all the way down to 185 degrees then waiting for the HX to rebound up to 198, but this seems to take a long time and I'm not sure the results are any better. Now I'm not sure what I'm doing wrong. Maybe I'm a victim of too much information. Sometimes life is easier when you live in ignorance.

Anyone have any suggestions for getting the most out of the thermometer?

[erics]

I have just adjusted my Anita's pstat such that it "reads" 1.0 bar MAX and am letting the machine stabilize at this setting. I'll post some graphs later on but keep in mind that my 1.0 bar and your 1.0 bar may not really be "exactly" 1.0 bar. And, of course, my 198 F may not be your 198 F. But that's OK because it is all relative.

For the puposes of discussion, I separate espresso production into two steps:

a. the preparation of the puck
b. the preparation of the machine

I choose to do a. and b. concurrently or rather near concurrently whereas lots of users choose the consecutive route. More later.

[edwa]

Beezer,

After a bit of experimenting and a post by Mike McKoffee I've been able to set up a routine which essentially uses the adapter as a rough guide.

1. Flush until desired temp. for me this is generally to around 202-203 ish I say "ish" as the temp is rapidly falling on my Fuji controller that is used only for readout purposes and it depends on how quick I push the lever. Remember the adapter is measuring temp on its way to the brew head so there is somewhere between 4-5 degrees higher on the readout.
2. I then grind my beans and and build my PF.
3. Because of the character of my Volante I then flush for a fast 2 count after the end of water dance. Generally about 4 oz. At this point my readout is hitting sometimes 208 to 210f It does vary.
3. At this point I'm standing poised with my built PF and watch temp fall down to 207, lock it in, and pull when its in the high 205's. I don't immediately lock in the PF after the 4 oz flush out of concern for changing the group head temp even further.

For the second shot, the 1 st is for my wife, I dump the puck, rinse the PF, rinse & wiggle the GH with my 2nd blind basket PF while grinding. Dry my naked PF build my shot and then:

1. Flush to a fast 2 count from dance ~ 4oz.
2. Same as 3 above.

In the beginning of my use of the adapter I had a hard time finding the right amount of initial flush, the one after a long idle. Eric and I emailed back and forth for quite some time, kudo's to Eric's patience, but what nailed it for me was a mention by Mike, I think, of flushing it to desired temp and then building. This may not be an exact enough method for some but its the closest I've gotten to temp stability. I've seen the readouts vary no matter how precisely I've repeated my actions.

Good luck and I hope this helps as a starting point.

[Beezer]

Thanks for the replies. I have been preparing my puck first, then flushing, waiting, then pulling the shot. This eliminates the second mini-flush before pulling the shot. It seems to me that this technique should work as well as doing the double flush, as long as the amount of the flush and the timing are right.

If the thermometer is reading ~ 5 degrees higher than the temperature at the puck, then if I'm shooting for a 198 degree temp at the puck I should be flushing until the thermometer reads a bit lower than 203, then waiting for it to rise a bit and then pulling the shot, right? Right now I'm flushing until the thermometer reads 198, waiting a few seconds, then pulling the shot. However, this results in a ~ 200 degree reading on the thermometer, which would be only ~ 195 at the puck. That might be too low. Maybe I need to flush less or wait longer after the flush before pulling the shot.

[erics]

Here is a graph showing grouphead and thermofilterfilter temperatures under the following conditions:

Anita fully warmed up - grouphead at 209 F, pstat seting is 1.0 bar MAX. I flushed to 198 F, waited 15 seconds, and then pulled simulated shot. Brew gage read 9.0 bar during shot.

I know you said that you flushed approximately 6 oz (turned out to also be 198 F), waited approx 15 sec and then pulled shot. This is very much like the method used by Bob Yellin and his Andreja Premium but I believe he is running a little higher pstat setting (don't know exactly but I believe it is around 1.10 bar) and he waited 30 seconds vice 15.

[stevendouglas]

Beezer,

I don't have an E61 Grouphead; however, I use a thermocouple located in a very similar location on my A3 and saw similar results to what you are seeing. I'm sure you have done so already, but the thread Monitoring Brew Temperature - E61 & Silvia contains a lot of great information.

When I was trying to figure out temperatures, I used a dual thermocouple thermometer and measured both the group head and the dispersion screen temperature (see the picture below, from Bob Barraza, and Bob's discussion on page 3 of the above referenced thread, for the setup of the dispersion screen). The dispersion screen temperature seems more representative of the puck temperature. I found the temperature at the dispersion screen was consistently 2F cooler than the group temperature. Thus, I shoot for a couple of degrees above target temperature (I use the Flush and Go method rather than Flush-Rebound-and-Go).

Have you tried flushing to the target temperature and pulling the shot? I flush it once (it peaks at over 220F after a long idle) down to around 200, build the puck, flush to target temp and then immediately pull the shot.

As for temperature drop, is this based on a 25 sec pull for a double? Obviously, a fast pull is closer to a cooling flush resulting in a larger temperature drop.

[jesawdy]

Here is a graph showing grouphead and thermofilterfilter temperatures under the following conditions:

Anita fully warmed up - grouphead at 209 F, pstat seting is 1.0 bar MAX. I flushed to 198 F, waited 15 seconds, and then pulled simulated shot. Brew gage read 9.0 bar during shot.

Eric-

I was a bit surprised to see the grouphead temp tracking below the thermofilter temp.... that's atypical is it not?

[erics]

Jeff, you are correct. I was simply matching my Anita's pstat and shot pulling method to what Beezer was doing plus it gave me an excuse to pull the shower screen and get it pristine for the thermofilter runs -

Typically (and I imagine we all sometimes dislike that word), the grouphead temperature and the thermofilter temperature approach one another pretty close at the conclusion of a normal double shot.

[Beezer]

Thanks for posting those graphs, Eric. It looks like a 15 second rebound after the flush might not be long enough to stabilize the group head, judging by the graph. Maybe I should wait more like 30 seconds. Still, the brew temp seems to be fairly stable, just dropping a couple of degrees during the shot. Not as stable as the other graph you posted, but still not too bad.

[Ozark_61]

Beezer - you're right on!

Steven - if you pull your shot right after hitting the target temp, you are probably going to cool off too fast during your shot.

Someone at cg had asked if I was compensating for the differential between the adapter and the top of the puck. I reflected on that thought and tested against another TC I had on my DMM. Eric's charts show it's not a constant differential. But, what I did realize, is that I should have played around with temp more. I was pulling most shots at 201' according to my adapter. I have found that shooting for 205' has actually dramatically improved some blends.

Play around with it a bit, try ± 3-5' and see how you like it.

You'll have to adjust your target cool down temp and your rebound time to compensate depending on your idle GH temp. But, heck, if it isn't a fun obsession, what kind of obsession is it?

Geoff

[Beezer]

OK, I checked the temperature of the group tonight after the machine had been on for about 30 minutes, and it was at 205 degrees. I waited another 20 minutes and it went up to 207. So I guess I do need to let the machine warm up some more. I didn't realize how long it takes for the group to get up to full temp.

I tried flushing to 198, waiting 30 seconds, then pulling the shot. The temperature on the thermometer went up to 200 or so and seemed to drop more slowly than before. I think it finished around 198. So it sounds like a longer rebound time is probably getting more stable temperatures for the shot. Since I made a cappuccino, it was hard to judge the quality of the shot, but it looked and tasted good to me.

One of these days I'll post a video of the flush, rebound, and shot pulling temperatures which might be instructive.

[erics]

It looks like a 15 second rebound after the flush might not be long enough to stabilize the group head, judging by the graph. Maybe I should wait more like 30 seconds. Still, the brew temp seems to be fairly stable, just dropping a couple of degrees during the shot. Not as stable as the other graph you posted, but still not too bad.

The extra 15 seconds would increase the group temperature by a few tenths but, more importantly, would raise the temperature of the water within the hx by more than a few tenths. So yes, the brew temperature line may become a little flatter BUT that does not necessarily translate into a better cup of coffee. As you said, the 15 second wait time showed reasonably stable temps. Of course, what would be interesting would be:

a. To see whether or not you could discern a difference between a 15 second wait and a 30 second wait.

b. And whether or not this method of operation fits YOUR production schedule.

For example, a pstat setting of 1.10 bar would speed the recovery of the machine between shots but instead of flushing, say, 6 ounces to reach 198, it may be 7 ounces. What matters most is repeatibility and the ease with which you can accomplish that repeatibility.

[pgreilich]

...merged with thread on related topic by moderator; also see Thermometer Adaptor and Brew Temperatures...


I recently installed a temp gauge in my Quickmill Anita and have a few questions. I see post that tell me to flush to 185 and let it come back up to 198; then pull the shot to arrive at a pull temp around 200. Here is the flow of temps I'm seeing: flush to 185, pops up to 200, then back down to 196 and crawls up to 198, pull shot, shoots up to 213, then quickly to 208, then down 1 degree every 2-3 seconds arrive at around 196 to 197 at shot end.

Eric S. says that if you flush to 185, pull shot at 198, your looking at around 201 pull temp (3 degrees higher than start temp). But what is really happening? If the puck temp is roughly 4 degrees less than the temp gauge, then what is really happening is that the puck is hit with at least 205 (the 208 temp less 3 degrees) a few seconds after the pull which then cycles down to a degree or two below the final temp reads of 196 to 197.

So is Eric S. just averaging the temp and making general statements that pull temp is 3-4 degrees higher than group temp at the start?

I tried flushing to 190 and pulling at 198; temp shot up to 215 and came down to 198. Had plenty of time to prepare puck. Shot quality very in both instances. Just getting the temp this close has really up the quality of my shots. Before I was flushing and based on the wait times I'm currently doing, before I would have been pulling shots before the machine recovered properly. Hugh difference.

Does it make a difference flushing down to 185 or 190 or is it just how much recovery time you need to prepare the puck?

Are the thermosyphon qualities different?

Would you get more stable overall pull temps by say flushing to 195 and pulling at 198 vs. flushing to 185 pulling at 198? Still talking about a 16 to 17 degree range in both cases.

Again, temp shots up at beginning of pull and drops 4-5 degrees in seconds and then crawls down as shot progresses. Is there anyway to mitigate the first burst at the beginning of the pull? I assume this is because boiler water recovery is way high and when it hits the E61 group, it is pulled down.

Thanks!

[SLC]

I am also confused about the 3-4 degree difference.

I flush down to 202. It then drops to 198. I get the shot ready (20 seconds) and then pull. The temp pops up to 206ish then 3/4 way into the shot is at 200-199ish. My understanding is that the final temp (199ish) is the actual temp of the water hitting the puck. The 3-4 degree difference is the reading when you start the pull.

Could someone correct me on the above thinking or affirm. I will then put my red cape back on and prepare a shot as directed.
Thank you,
Mark

[erics]

Here is a graph of MY Anita's water temperatures during the course of a flush to ~185 and recovery to 200. Typically, I would initiate a shot when the group hits 198 and, at that time, the average temperature in the thermosyphon loop is ~207.

Group Inlet and Group Outlet are the two thermosyphon lines connected to the grouphead and temperatures were measured ON the piping where it enters the group using self-adhesive Type T thermocouples. During a flush (and shot), water actually enters the grouphead through both of these pipes. When you follow this particular methodology, you are using the grouphead to cool the flowing water and additional cooling takes place in the water path DOWNSTREAM of where the probe is located - see the graph in my post (in this thread) on 7/27/07. This depicts what is happening when you initiate a shot at a grouphead temp of ~198 (on the way up) after a flush to ~185.

Does it make a difference flushing down to 185 or 190 or is it just how much recovery time you need to prepare the puck?

This is difficult to answer and, in fact, may have no answer that would fit all circumstances for a particular machine's settings and duty cycle imposed. For MY particular routine, it would simply mean starting the flush after the beans had been ground as compared to a simultaneous start or something close to that - it is about 6 seconds difference. That would be a lot of testing to see if a difference could be displayed graphically AND that wouldn't matter in the least if the difference could not be discerned in the cup.

Would you get more stable overall pull temps by say flushing to 195 and pulling at 198 vs. flushing to 185 pulling at 198? Still talking about a 16 to 17 degree range in both cases.

No, it would be just the opposite but that doesn't mean to imply that it would ABSOLUTELY be better. I could flush the machine to ~185 and pull a shot at ~198 (and repeat this process 10 times) and you would be hard pressed to see the difference in the shots graphically. If I flushed to 195 and pulled the shot at 198 - well I don't believe you would ever see 198 in that case - at least I haven't.

There are additional tips on using the adaptor here in which several ways of pulling a shot are graphed.
need-hints-on-using-e61-thermocouple-adapter-t5125.html

[SLC]

so on the thermometer adapter am I wrong in understanding that the readout I am getting toward the end of the shot is the temp of the water hitting the puck which should be a 198-202ish readout?
thanks.

[erics]

SLC - You are correct in assuming that the temperature as read by the digital thermometer is easily within the range you quoted PROVIDED you have performed the flush and wait procedure and PROVIDED you are pulling a "normal" double shot.

I will cheerfully admit that, from what I have read (and I do read all of the posts associated with the adaptors), the majority of users out there DO NOT follow a flush and wait procedure.

[SLC]

thanks eric. I flush to about 1-2 seconds after the water dance. I prepare the shot (20-30 seconds). I do a quick second flush for about 2 seconds and then about 5 seconds later I pull the shot.

If I do that then usually the readout is at about 199 toward the end of the pull.

The method above seems to be the same as a longer pull with a little more wait time.

Correct me if I am off.

[erics]

Correct me if I am off.

SLC, there exists so many other variables, it would be difficult, if not impossible, to comment. I will say that I have not flushed a machine as you do but I have read where others do. From what you have said, you are using the group to heat up the incoming brew water which is what a flush & go method does. I showed in some graphs in the previously referenced post - need-hints-on-using-e61-thermocouple-adapter-t5125.html that the same results could be achieved in several different ways.

An important point is that, during the course of a shot, you have about 9.0 lbs of brass that you're passing 2.0 ounces of water through. I think it is pretty easy to see "who the boss is." Hence, my leaning towards cooling the group such that it is just below desired brew temperature and then letting it "do its thing" to the relatively hotter water from the hx.

Repeatibility is the key here and even that may very well hinge on how sensitive the bean or bean blend is to a consistent temperature profile. If you are able to essentially duplicate results with any method employed, that is what counts.

[SLC]

Thank you Eric. I really appreciate your responses. I will play around with different flushing methods and see how the temp changes and how my taste buds react.