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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?

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.

Beezer,

After a bit of experimenting and a post by Compass Coffee 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.

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.

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.

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.

erics wrote: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?

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.

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.

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