Erics e61 adapter, how to pull consecutive shots?
- nixter
- Posts: 785
- Joined: 16 years ago
Yes another Erics adapter thread.
Anyhow the machine is a rocket giotto evoluzione, 0.9 - 1.1 bar, rotary@9bar, reservoir.
I've read every Erics adapter thread and I'm finding it less than straight forward. I've had the adapter for a few days and played with a few routines mostly unsuccessfully but this is largely due to lack of time in the morning. This morning I tried a flush 'n go but I flushed too long. Idled at 209, flushed to 203, pulled immediately which leveled around 194.Tonight I'll try less of a flush. I'm curious though, once I hit the nail in the head, (let's say that means flushing to 206 and a pull leveling around 200), in order to pull consecutive shots at a similar temp will I have to wait for the machine to recover back above 206 so i can flush again? That would take a LONG time. Would it make sense to do as TimEggers does and turn up the pstat for faster recovery?
Dan, if you feel this thread should be part of the other adapter threads that's fine by me.
Anyhow the machine is a rocket giotto evoluzione, 0.9 - 1.1 bar, rotary@9bar, reservoir.
I've read every Erics adapter thread and I'm finding it less than straight forward. I've had the adapter for a few days and played with a few routines mostly unsuccessfully but this is largely due to lack of time in the morning. This morning I tried a flush 'n go but I flushed too long. Idled at 209, flushed to 203, pulled immediately which leveled around 194.Tonight I'll try less of a flush. I'm curious though, once I hit the nail in the head, (let's say that means flushing to 206 and a pull leveling around 200), in order to pull consecutive shots at a similar temp will I have to wait for the machine to recover back above 206 so i can flush again? That would take a LONG time. Would it make sense to do as TimEggers does and turn up the pstat for faster recovery?
Dan, if you feel this thread should be part of the other adapter threads that's fine by me.
- nixter (original poster)
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- Joined: 16 years ago
Anyone? Mainly want to know how to reproduce the previous shot's curve without waiting for the machine to fully reset to idle temp. I can use flush'n wait or flush'n go if one works better for producing a similar 2nd shot.
- HB
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The answer depends on the espresso machine's heat exchanger characteristics; I elaborated on this point in Olympia Maximatic - Second Look, excerpted below:
Sorry if this sounds vague; if you want hyper-precise brew temperatures, longer waits between shots is always better, but with a little practice and attention to the taste, you'll know the right flush time intuitively.
PS: Another alternative, if you don't mind long flushes, is increasing the steam boiler pressure. That will increase the flush amount, raise the profile temperature near the end of the extraction, and reduce thermal memory. However, I don't recommend this approach for new owners since it decreases your margin of error. See What is the "right" boiler pressure setting? of Managing HX Brew Temperature for more details.
It's been years since I used the cousin of your Evoluzione, the ECM Giotto, but I remember it being a Dragon with Mixer tendencies. If the basic behavior remains unchanged, it runs hot, flushes long, and has moderate thermal memory. So for back-to-back shots, you would follow the usual idle flush-to-brew routine for the first shot, then from that point forward, a short flush before each shot. If it flash boils, continue to approximately half the time of the usual idle flush-to-brew time and the usual rebound time; otherwise flush briefly and maybe a smidgen less rebound time.HB wrote:Having written a number of reviews, I've come to recognize differing degrees of how heat exchanger-centric a particular espresso machine is. My shorthand for these distinctions are:
As the last entry suggests, these categories are not immutable. With minor modifications or boiler pressure adjustments coupled with barista techniques, an espresso machine that naturally fits in one category can morph into one of the other categories (e.g, Ian's HX Heaven or 1½ Boiler).
- Dragon - key characteristics are lots of flash boiling, fast recovery, nearly zero thermal memory, and slowly rising brew temperature profile. Simply stated, after the cooling flush, the heat exchanger output is the brew temperature. Examples include the Elektra Semiautomatica, Gaggia Achille, and the Olympia Maximatic.
- Mixer - key characteristics are modest flush, medium to slow recovery, considerable thermal memory, and initial rising then falling brew profile. Unlike the Dragon, the Mixer's brew temperature isn't determined solely by the output of the heat exchanger. Other factors, such as cool water mixing via an heat exchanger injector, backflow from a thermosyphon, and the attenuating effect of a heavy grouphead temper the final brew temperature. Examples include HX E61 espresso machines like the Vibiemme Domobar Super and Quickmill Vetrano.
- Agnostic - key characteristics are small, fixed volume flush or none at all, and long thermal memory. Careful tuning of a Mixer with tweaks in the design can produce an espresso machine that is heat exchanger in name only. Examples include the Cimbali Junior and Nuova Simonelli Aurelia.
The practical benefit of recognizing the characteristics of heat exchangers is the time saved learning the correct brew temperature management scheme (**). For example, I recognized the Maximatic as a Dragon by flushing the group until the water stopped flash boiling, waiting a minute or so, then repeating; it was fully recovered. The Elektra Semiautomatica is also a Dragon with a slightly heavier grouphead, but they share the same flush-n-go technique for targeting the brew temperature.
Sorry if this sounds vague; if you want hyper-precise brew temperatures, longer waits between shots is always better, but with a little practice and attention to the taste, you'll know the right flush time intuitively.
PS: Another alternative, if you don't mind long flushes, is increasing the steam boiler pressure. That will increase the flush amount, raise the profile temperature near the end of the extraction, and reduce thermal memory. However, I don't recommend this approach for new owners since it decreases your margin of error. See What is the "right" boiler pressure setting? of Managing HX Brew Temperature for more details.
Dan Kehn
- nixter (original poster)
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Thanks Dan. They may be distant cousins at best. Even after an overnight idle I get zero flash boil. I did increase my pstat to 1.1 and now my idle is 209. Still no flash boil though. Odd.
- HB
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That's surprising. Perhaps they've installed a thermosyphon restrictor. Or the thermosyphon has stalled (?).
Dan Kehn
- nixter (original poster)
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Not sure about the restrictor but I don't see it mentioned in the specs nor a very detailed review i've read of it. Doubt the stalling as it's easy to burn shots and my therm tells me the temps are high. idle 209, initial flush spike of 216
- erics
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Naturally, I view temperature (and other measurable variables) as being very important in the quest to produce consistent (and pleasing) espresso. This is sorta hellacious for me, having the poor tastebuds I do but . . . I primarily drink 7 oz cappuccinos and that, in and by itself, further deflates the taste - maybe.
The best methodology to use on hx machines when the goal is to create multiple, consecutive shots is a flush-n-wait technique. The rationale behind this is the initiation of the shot at a consistent grouphead temperature AND a fixed temperature of the water within the tubes feeding the grouphead. The grouphead is being used to cool the water passing through it. Temperatures read by a thermometer in the grouphead are typically 3 degrees above that presented to the coffee.
The reason that the 1st shot is relatively "hot" in the above graph is that the hx water was (inherently) given some extra time to heat up due to the extended flush. If I were to do this again, I would make, say, a one degree grouphead offset for the 1st shot and I would do a 1-2 second screen flush between shots.
The most common method of pulling shots on a hx machine is simply flush-n-go. Here you are (obviously) injecting some cold water in the hx but not doing much to the grouphead temperature. After all, it does take a bit of water to cool down 9 lbs of brass. In this method, the grouphead is being used to raise the temperature of water passing through it. Temperatures read by a thermometer in the grouphead are typically 3 degrees below that presented to the coffee.
The best methodology to use on hx machines when the goal is to create multiple, consecutive shots is a flush-n-wait technique. The rationale behind this is the initiation of the shot at a consistent grouphead temperature AND a fixed temperature of the water within the tubes feeding the grouphead. The grouphead is being used to cool the water passing through it. Temperatures read by a thermometer in the grouphead are typically 3 degrees above that presented to the coffee.
The reason that the 1st shot is relatively "hot" in the above graph is that the hx water was (inherently) given some extra time to heat up due to the extended flush. If I were to do this again, I would make, say, a one degree grouphead offset for the 1st shot and I would do a 1-2 second screen flush between shots.
The most common method of pulling shots on a hx machine is simply flush-n-go. Here you are (obviously) injecting some cold water in the hx but not doing much to the grouphead temperature. After all, it does take a bit of water to cool down 9 lbs of brass. In this method, the grouphead is being used to raise the temperature of water passing through it. Temperatures read by a thermometer in the grouphead are typically 3 degrees below that presented to the coffee.
-
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I am a recent convert from flush-and-go to flush-and-wait on my Anita, and I've noticed a huge improvement in the consistency of the flavor of my espresso.
While I understand erics' multiple shot protocol for espresso shots (i.e., flush-and-wait for the first shot, then simply wait until the grouphead temperature rises to your target temperature after pulling the first shot to start to pull a subsequent shot), I am confused what to do if I steam milk after one of the shots, since in the time it takes to steam milk, the grouphead temperature has risen above my target temperature. I've been doing another flush-and-wait in this case, but I'm wondering if there are any other techniques to eliminate another full flush.
While I understand erics' multiple shot protocol for espresso shots (i.e., flush-and-wait for the first shot, then simply wait until the grouphead temperature rises to your target temperature after pulling the first shot to start to pull a subsequent shot), I am confused what to do if I steam milk after one of the shots, since in the time it takes to steam milk, the grouphead temperature has risen above my target temperature. I've been doing another flush-and-wait in this case, but I'm wondering if there are any other techniques to eliminate another full flush.
- nixter (original poster)
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- Joined: 16 years ago
Last night and this morning I started getting audible flash boiling! I have no idea why as my idle temp has not changed. For now I'll put it down to some sort of break in period.
Anyhow, I'm finding the delay of the therm a bit tricky. During a flush as the grouphead temp starts lowering, it does so in jumps of 1, 2 and 3 degree increments. It's almost impossible to hit an exact number within even +/- 1 degree. Perhaps the exact flush is not as important as the temp you initiate the pull at after the "wait" period?
What's an ideal "wait" period? 30 seconds? 45? Ok, nevermind "ideal" but would 45 sec be good to use as a constant in order to tweak the "flush to" and "pull at" temps?
About temp offset.. if I have a brew target of 201 for my 49th parallel beans then should I be aiming for 205 at the group therm?
Anyhow, I'm finding the delay of the therm a bit tricky. During a flush as the grouphead temp starts lowering, it does so in jumps of 1, 2 and 3 degree increments. It's almost impossible to hit an exact number within even +/- 1 degree. Perhaps the exact flush is not as important as the temp you initiate the pull at after the "wait" period?
What's an ideal "wait" period? 30 seconds? 45? Ok, nevermind "ideal" but would 45 sec be good to use as a constant in order to tweak the "flush to" and "pull at" temps?
About temp offset.. if I have a brew target of 201 for my 49th parallel beans then should I be aiming for 205 at the group therm?
- erics
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Simple - just either remember to do a screen flush after your 1st shot or extend the screen flush by 1 second, by 2 seconds, by 3 seconds, etc., etc.. . . I am confused what to do if I steam milk after one of the shots . . .