Eric E61 Thermometer Flushing on Rocket Appartamento Temperature Questions

Need help with equipment usage or want to share your latest discovery?
endurancematt

#1: Post by endurancematt »

I'm new to HX machines and recently bought a Rocket Appartamento and installed Eric's E61 thermometer. I have read that Rocket machines best utilize the "flush and go" tactic, but it seems when I do this the thermometer always reads around 206 degrees for the duration of each shot.

I've also tried super long initial flushes before my first shot bringing it down to 185-190 degrees which can get the temp down a bit, but I'm having trouble locking in a routine that will get my shot temperature closer to 200 degrees. Does anyone have any ideas?

Thanks!

User avatar
sweaner
Supporter ♡

#2: Post by sweaner »

But...how are your shots?
Scott
LMWDP #248

Aida Battle: Indigo Reserve from world renowned Finca Kilimanjaro in El Salvador
Sponsored by Aida Battle
endurancematt (original poster)

#3: Post by endurancematt (original poster) » replying to sweaner »

Good question! :)

When I do the short flush and go they usually wind up pretty decent - maybe a tad on the bitter side though. When I experimented with the really long flushes, they weren't very good - quite sour.

allemania

#4: Post by allemania »

This may be tangential since I've got a Profitec Pro 500 with Eric's thermometer. However, given that they are both heat exchangers with similar boiler sizes (I believe) and E61 group heads, perhaps my experience will help. I very thoroughly read Eric's instruction's and explanation of the flush and go technique and the most important fact I came away with was that the temperature at the puck during extraction was approximately 3 to 5 degrees higher than what the thermometer displays during the extraction. I use a bottomless portafilter and dose 18 grams. My shot duration is in the 25 to 30 second range timed from lifting the brew lever. The group is usually idling at 204 to 205 Celsius. My process and observation is as follows:

1. Flush the group until the flash boiling completely stops and then continue to flush for 5 to 6 seconds. The thermometer peaks at 210 to 211 (corresponds to the end of flash boiling) and then drops gradually to 206 to 205 Celsius at which point I stop flushing.

2. I've already prepped my portafilter with coffee so I wait about 20 seconds, lock in the portafilter and place my scale with cup beneath it. That takes another 5 to 10 seconds (I'm estimating) and then I pull my shot. The initial temp prior as the puck begins to be saturated with water (and thus no actual flow through the group) is around 200 Celsius. Once the initial flow starts (after 5 seconds, approximately, assuming I'm having a good barista day!) the temp hovers around 197.5 to 198 C and then gradually decreases to around 195 C by the end of the shot, output in the cup being around 36 grams. Assuming Eric's observation of actual brew temp being 3 to 5 degrees higher than the temp on the display, that gives me a brew temp beginning slightly at or above 200 C and ending slightly below 200 C.

I recently had a roast that I felt tasted better at a lower brew temp, so I would lock in the portafilter immediately after flushing (so perhaps a 5 to 10 second interval) and the brew temp is noticeably lower, starting at 195 and ending around 193. My point is that use the flush and go method and change the post flush interval to affect brew temp.

Hope this helps.

I realize you that given you have a an Appartmento the numbers may vary slightly but I assume that the basic technique would yield similar dynamics.

allemania

#5: Post by allemania »

I just reread your post and saw you mentioned a temp of 206 C when pulling a shot using flush and go. How is shot flow rate? It sounds like you may be grinding too fine or dosing to high and that there is too much resistance when pulling a shot and thus causing a temperature spike. Just a thought. However, if your getting around a 5 second delay before the flow starts and 25-30 seconds for a shot duration, then my observation is incorrect. Also, are you weighing your doses and shot output?

endurancematt (original poster)

#6: Post by endurancematt (original poster) »

allemania wrote:This may be tangential since I've got a Profitec Pro 500 with Eric's thermometer. However, given that they are both heat exchangers with similar boiler sizes (I believe) and E61 group heads, perhaps my experience will help. I very thoroughly read Eric's instruction's and explanation of the flush and go technique and the most important fact I came away with was that the temperature at the puck during extraction was approximately 3 to 5 degrees higher than what the thermometer displays during the extraction. I use a bottomless portafilter and dose 18 grams. My shot duration is in the 25 to 30 second range timed from lifting the brew lever. The group is usually idling at 204 to 205 Celsius. My process and observation is as follows:

1. Flush the group until the flash boiling completely stops and then continue to flush for 5 to 6 seconds. The thermometer peaks at 210 to 211 (corresponds to the end of flash boiling) and then drops gradually to 206 to 205 Celsius at which point I stop flushing.

2. I've already prepped my portafilter with coffee so I wait about 20 seconds, lock in the portafilter and place my scale with cup beneath it. That takes another 5 to 10 seconds (I'm estimating) and then I pull my shot. The initial temp prior as the puck begins to be saturated with water (and thus no actual flow through the group) is around 200 Celsius. Once the initial flow starts (after 5 seconds, approximately, assuming I'm having a good barista day!) the temp hovers around 197.5 to 198 C and then gradually decreases to around 195 C by the end of the shot, output in the cup being around 36 grams. Assuming Eric's observation of actual brew temp being 3 to 5 degrees higher than the temp on the display, that gives me a brew temp beginning slightly at or above 200 C and ending slightly below 200 C.

I recently had a roast that I felt tasted better at a lower brew temp, so I would lock in the portafilter immediately after flushing (so perhaps a 5 to 10 second interval) and the brew temp is noticeably lower, starting at 195 and ending around 193. My point is that use the flush and go method and change the post flush interval to affect brew temp.

Hope this helps.

I realize you that given you have a an Appartmento the numbers may vary slightly but I assume that the basic technique would yield similar dynamics.
Thanks for posting this - you actually have no idea how much it helped. I just pulled my first shot of the day after a long idle / warm up (my machine automatically comes on early in the morning). I had to flush a good bit to get down to 205-ish without the portafilter in place, but I did that when I followed your technique the shot pulled with the display reading right around 197 - 198 for the duration of the shot, which indicates around a 200ish shot temperature. I guess my machine just requires a much longer (10 seconds or so) initial cooling flush when it's been idle for a couple hours. Does this sound normal? Either way, this shot was the most balanced tasting yet!

Shot flow rate is good. I single dose by weight and weigh my shots - I put 18g in a VST 18g basketand get 36g out in 30 seconds or so, and the flow begins at around 5 seconds. I'm going to keep paying attention but I'm hoping that the flush to 205 after a long idle will be the ticket for me. Thanks!

allemania

#7: Post by allemania »

You're welcome! I've gotten a lot knowledge and assistance on this forum so it's nice to try to return some of it.

If you're flushing for about 10 seconds after initial warm up (or long idle time) and that includes flash boil time then that sounds very similar to my Pro 500. If you're flushing for 10 seconds AFTER flash boiling ends then I guess that's likely a result of design differences between these two machines.

Sounds like you have it figured out :D

ECM Manufacture: @ecmespresso #weliveespresso
Sponsored by ECM Manufacture
maki

#8: Post by maki »

watch this:
LMWDP #630

wai2cool4u
Supporter

#9: Post by wai2cool4u »

I also have an appartamento with Eric's thermometer. After more than 30 mins of idling, I'll usually read about 207-208 on the grouphead.

During the flush, temps will climb to 211 and start dropping. it usually takes me more than 10 secs of flushing to get the temps to start dropping after hitting 211. Once the temps start dropping I usually stop the flush and the grouphead will continue to cool down until I pull my shot. I'm usually reading 195-198 after pulling a shot.

I haven't done many back to back shots but from my limited experience, it seems like it takes more than a couple mins for the grouphead to stabilize (i.e. climb back into 200+ range).

Bradfraser14

#10: Post by Bradfraser14 »

I agree with the suggestion that after a long idle to flush to ~205, wait ~20 seconds and pull the shot. This approach is giving me a consistently balanced shot. One thing I would add is that I needed a very long cooling flush to get the temp on Eric's thermometer down to this level. I think the Appartamento's factory setting boiler pressure is tuned too high. I brought it down to just under 1.0 bar pressure and the flush time, while still not insignificant, is now greatly reduced. Prior to getting the thermometer, I had no idea my machine was running so hot after a long idle, which required flushing much past the end of the water dance than I expected. Eric's thermometer is a must have for this machine IMO.