Our Valued Sponsor
OpinionsConsumer ReviewsGuides and How TosCoffeeGeek ReviewsResourcesForums
Espresso: Espresso Machines
Timing the cooling flush on E61 machines?
Cafe Solutions
Commercial sales and service, nationwide installation, equipment leasing options.
www.seattlecoffeegear.com
 
Not Logged in: Log In to Postlog in
New Topics updated topics   New Posts new posts   Unanswered Posts new unanswered  
Search Discussion Board search   Discussion Board FAQ faq   Signup sign up  
Discussions > Espresso > Machines > Timing the...  
view previous topic | view next topic | view all topics
showing page 3 of 7 first page | last page previous page | next page
Author Messages
HB
Senior Member


Joined: 3 Apr 2003
Posts: 2,913
Location: Cary, NC
Posted Wed May 11, 2005, 5:29am
Subject: Re: Timing the cooling flush on E61 machines?
 

singforsupper Said:

Therefore my question is....   IS THERE SOMETHING I'M NOT ACHIEVING?

Posted May 10, 2005 link

Is the taste consistent from shot-to-shot? If the answer is yes, then I don't see a problem.

 
www.home-barista.com
back to top
 View Profile Visit website Link to this post
scrutinizer
Senior Member


Joined: 16 Feb 2005
Posts: 109
Location: Arlington, VA
Expertise: I love coffee

Espresso: Andreja Premium
Grinder: Vario, Rocky
Vac Pot: Yama
Drip: French Press
Roaster: Alpenrost, Behmor 1600
Posted Thu May 19, 2005, 4:12pm
Subject: Re: Timing the cooling flush on E61 machines?
 

scrutinizer Said:

Thus, generally after the initial 6 oz flush, subsequent flushes of 1.5 to 2 oz every 1.5 to 2.5 minutes seem to keep the machine in a reasonable temperature range.  Since I'm slow, I might actually flush 2 times after the 6oz flush while I'm grinding/tamping.  After the final flush I wait 35 to 40 seconds for the pull.  Generally, I'm doing 1.5 ounce shots with "just before oil" (or "just after oil") moderate full city to vienna roasts.  I've found the 40 second wait is good for cappas (a bit bolder) and maybe 30 to 35 is good for shots.

This routine is somewhat annoying in the number of flushes required (and it does put more wear and tear on the machine) but i do like the idea of stabilizing the temp of the group w/ more shots than just 1.  However, it might be unnecessary so long as the combination of machine settings (e.g., boiler temp) and the flush routine are calibrated so you can hit the right temp during the pull.  There are obviously many ways to flush, but this is what works for me, so far.  In the near future, I'll probably go back to "single flush" routine and see if there is a noticeable difference (reconizing that it might not be possible to consider "flush routine" in isolation from the machine settings since both might need to be optimized to get the best results).  

Pat

Posted May 9, 2005 link

Just a followup on my earlier post (quoted above).  I have switched back to the 6oz initial flush following idle and then only a 2nd 1.5 to 2oz flush and 40 sec or so wait and pull routine (most of my few shots per day are following warm up or long idle).  This is generally consistent with Dan's article and many other posts on the topic.  Compared to my prior routine of pulling multiple shot volume flushes every few minutes the simpler approach appears to produce a better tasting cappa in my opinion (at least for my 1.1--1.2 bar boiler element on/off setting).  

I think the multiple flush routine was cooling the group too much or at least (perhaps) lowering the initial "hump" in the temp curve discussed in Dan's article.  It seems reasonable that a multiple flush routine aimed at cooling the group closer to brew temps might lead to less shot temp variation over the duration of the pull but that might not necessarily lead to better espresso (i.e.,  at least the way I prefer it to taste in my cappas).

Thus, after some additional tinkering and tasting, I prefer the simpler approach to flushing that uses less water (in my case leading to less scale buildup and less hassle).  No point in making it more difficult if it doesn't improve the results.  

Pat
back to top
 View Profile Link to this post
e61brewski
Senior Member
e61brewski
Joined: 7 Dec 2004
Posts: 131
Location: greenville, sc
Expertise: I live coffee

Espresso: isomac tea, riviera lever
Grinder: mazzer major, isomac gran...
Vac Pot: dirt devil lx
Drip: wouldn't dare
Roaster: i-roast
Posted Fri May 20, 2005, 12:29am
Subject: Re: Timing the cooling flush on E61 machines?
 

given the nature of the craft to begin with, i believe flushing with your senses only (ears and eyes, mainly) is beneficial in more ways than one. measuring the water or timing the flush isn't reliable, especially if you turn your machine off every day. the isomacs particularly can run very hot (meaning the temp takes longer to bring down, rebounds quicker and cycles through the "green zone" slower) or it can run somewhat cooler, within the first two hours of operation for example (meaning the group temp is slower to rebound and stays in the "green zone" for less time).

i agree with jonR -- you listen first, getting a feel for when the hissing stops, plus a few seconds. eventually, you can watch as well, making it possible to flush precisely even with the grinder on. then you let the group temp rebound. this time can vary, based on (a) the kind of flavor profile you're shooting for, and (b) the way the machine is behaving. making this a science just kills the finer points of nailing that superb pull. i'll notice, for example, that while the machine is rebounding (for me, it's typically two trips through the green light, then brew on the third) it may linger longer in the green zone. that tells me the machine is especially hot, allowing the heater to stay off for a longer period of time, and i'll cut the rebound short by a few seconds before locking and pulling.

similarly, if i'm brewing a lot of shots and keeping the grouphead fairly cool with constant use, then my flushes are shorter and my rebound periods slightly longer. but the behavior of the boiler gauge, the sound of your flushes and of course the taste of your shots all help you get a feel for this. after awhile, it becomes unconscious. you can flush while grinding, then watch the green light cycles while tamping, then lock and pull a bit early or late, or even adjust the routine based on what kind of flavors you want out of a particular bean. with my kenya karatina, i love underdosing a bit and brewing it a bit hot -- great leather and dark chocolate hints.

all this is a part of the e61 fun. stressing over flushes and rebound times only forces you into a set of rigid rules that should be flexible. my advice: taste a lot of espresso. get to know your machine. then tweak the factors based on your sensory feel and brewing whim. it takes time, but it's not hard.

 
the blog: http://ben.szobody.com
back to top
 View Profile Visit website Contact via AOL Instant Messenger Link to this post
Tomcat
Senior Member


Joined: 15 Jul 2004
Posts: 79
Location: Frankfurt/Germany
Expertise: I love coffee

Espresso: QM Eliane, Bezzera B2000
Grinder: Mazzer Mini, Mazzer Kony
Posted Fri May 20, 2005, 1:41am
Subject: Re: Timing the cooling flush on E61 machines?
 

I have no E61 HX machine and thus no experience with flushing them, but a 6 oz. cooling flush somehow sounds excessive.

My Bezzera B2000 has a 5l boiler and a 350ml HX (and a Gino Rossi thermosyphon group). If I flush more than 3 oz. or 3.5 oz. before starting the first shot in a series, my shots suck. They first one starts out burned and the following ones tend to be too cold. Therefore: my initial flush is 3 oz. and my flush before each following shot in a series is 1 oz or less. I wonder how a semi-commercial E61 HX machine with its much smaller thermal mass can possibly cope with the heat loss if its HX is completely drained and cooled by the big initial flush? Does anybody know whether a similar flushing routine is advisable for a big commercial E61 machine, with large boiler and large HX? Is it really true that a commercial E61 HX system is so far off its operating point when idling that it needs as much flushing? If the same reasoning as for semi-commercial E61s applied -- draining the HX, several times -- you'd need a lot more than an initial 6 oz. flush.
back to top
 View Profile Visit website Link to this post
scrutinizer
Senior Member


Joined: 16 Feb 2005
Posts: 109
Location: Arlington, VA
Expertise: I love coffee

Espresso: Andreja Premium
Grinder: Vario, Rocky
Vac Pot: Yama
Drip: French Press
Roaster: Alpenrost, Behmor 1600
Posted Fri May 20, 2005, 7:58am
Subject: Re: Timing the cooling flush on E61 machines?
 

Tomcat Said:

{snip} Does anybody know whether a similar flushing routine is advisable for a big commercial E61 machine, with large boiler and large HX? Is it really true that a commercial E61 HX system is so far off its operating point when idling that it needs as much flushing? If the same reasoning as for semi-commercial E61s applied -- draining the HX, several times -- you'd need a lot more than an initial 6 oz. flush.

Posted May 20, 2005 link

I'm not very knowledgeable about commercial machines but I would guess that some would have separate boilers for steaming and pulling shots, and in that case, I believe overheating the group is not an issue since the boiler temp is optimized for brew temps and not both steaming and brewing.  Your question brings to mind a local bread/coffee shop in my area that has a small 1 or 2 group "Brasilia" machine with E61 and, while I know nothing about this machine, its quite obvious from the get go that a) they are not doing ANY flushing before they pull, and b) every shot they pull is so overextracted that its not really drinkable (perhaps the machine's boiler setting is way off as well).  They use Starbucks coffee and the pulls are WAY to hot for this (boiling bitter burnt cardboard overtones!).  I was thinking of recommending they try a flush but was holding back...assuming such suggestions wouldn't go over too well with the staff (sort of like telling a bartender how to make a drink....even though I've been known to do that on occaision ;)

I also agree with the prior post on using more of the senses for flushing rather than rigid time and volume rules.  I think the general 6oz following idle and another shot a few minutes later followed by a 30--45 or so seconds wait prior to the pull is a reasonable "rule of thumb" starting point that, with additional experience, can be optimized by more sensory fine tuning.  I'm not really measuring volumes precisely when I flush, although my cappa cup just happens to be 6 oz and about 1/3 of a cup is about 2 oz, so even though I'm watching the "dance" of the flush while I'm doing it....usually it ends up being the same amt.  Because my morning routine is fairly fixed, and my brew water is added in the same amout every morning straight from the brita pitcher in the 40 deg refrigerator, and the warm up time is the same every day....most of the other non machine temp variables are fairly controlled.  

With experience it becomes much easier to use the senses with the flushing, but as a recent convert to the E61 (formerly I had a Sylvia), I found initially that the "sound and vision" approach was a bit hard to follow and some basic time and volume parameters helped as a starting point necessary to gain some additional experience with the machine and better understand the subtleties of the sights and sounds.  

Pat
back to top
 View Profile Link to this post
Tomcat
Senior Member


Joined: 15 Jul 2004
Posts: 79
Location: Frankfurt/Germany
Expertise: I love coffee

Espresso: QM Eliane, Bezzera B2000
Grinder: Mazzer Mini, Mazzer Kony
Posted Fri May 20, 2005, 9:24am
Subject: Re: Timing the cooling flush on E61 machines?
 

scrutinizer Said:

I'm not very knowledgeable about commercial machines but I would guess that some would have separate boilers for steaming and pulling shots, and in that case, I believe overheating the group is not an issue since the boiler temp is optimized for brew temps and not both steaming and brewing.

Posted May 20, 2005 link

Pat,

Yes, sure. But those double boiler machines aren't E61 HX machines, are they?  ;-)  

And in Italy, Wega and La Cimbali HX machines are much more popular than La Marzoccos. Commercial double boiler machines are very rare in Italy.

I just wonder whether all this flushing leads to a temperature profile that is much flatter and cooler than originally intended when the E61 was deisgned. It might be that excessive flushing mimicks the temp behaviour of a double boiler machine - that's not what the E61 or any other thermospyphon HX machine has been designed for.
back to top
 View Profile Visit website Link to this post
HB
Senior Member


Joined: 3 Apr 2003
Posts: 2,913
Location: Cary, NC
Posted Fri May 20, 2005, 10:24am
Subject: Re: Timing the cooling flush on E61 machines?
 

Tomcat Said:

Does anybody know whether a similar flushing routine is advisable for a big commercial E61 machine, with large boiler and large HX? Is it really true that a commercial E61 HX system is so far off its operating point when idling that it needs as much flushing?

Posted May 20, 2005 link

I've used the Cimbali Junior (2.5L boiler) and Elektra A3 (6L boiler) a fair amount and they don't behave much like your typical prosumer HX. The flushes are a lot, lot shorter; they're almost an afterthought.

-- Dan

 
www.home-barista.com
back to top
 View Profile Visit website Link to this post
Tomcat
Senior Member


Joined: 15 Jul 2004
Posts: 79
Location: Frankfurt/Germany
Expertise: I love coffee

Espresso: QM Eliane, Bezzera B2000
Grinder: Mazzer Mini, Mazzer Kony
Posted Sat May 21, 2005, 1:46am
Subject: Re: Timing the cooling flush on E61 machines?
 

HB Said:

I've used the Cimbali Junior (2.5L boiler) and Elektra A3 (6L boiler) a fair amount and they don't behave much like your typical prosumer HX. The flushes are a lot, lot shorter; they're almost an afterthought.

Posted May 20, 2005 link

Thanks, Dan!

That's what I suspected. But do you have a theory why that is the case? Conventional wisdom says that all HX machines have super-heated water in the HX one has to get rid of first. At least for big commercial machines, super-heated water in the HX doesn't seem to be a problem, or not as much of a problem. Why?
back to top
 View Profile Visit website Link to this post
HB
Senior Member


Joined: 3 Apr 2003
Posts: 2,913
Location: Cary, NC
Posted Sat May 21, 2005, 11:07am
Subject: Re: Timing the cooling flush on E61 machines?
 

Tomcat Said:

At least for big commercial machines, super-heated water in the HX doesn't seem to be a problem, or not as much of a problem. Why?

Posted May 21, 2005 link

Here was my take on the subject based on what I've read and observed (corrections welcome):

The Cimbali Junior still needs to be flushed, but not nearly the same volume as a prosumer E61.

One reason for this difference is the size of their respective heat exchangers. Junior’s heat exchanger is much larger and a smaller percentage of its total volume is submerged in the boiler water compared to Andreja’s. The deeper a heat exchanger is submerged in the boiler water, the faster the heat exchanger’s temperature will rise since water conducts heat much more quickly than steam. If you don’t remember your high school physics, think of it this way—you’ll sweat profusely in a sauna heated to 140°F, but the consequences of immersing yourself in water at that same temperature for even ten seconds would be gravely serious.

The commercial La Spaziale machines take this a step further by having their exchangers heated in a steam jacket (not partially in water / partially in steam as is typically the case). Their website used to have a very nice technical explanation of the design, which I believe they patented, but I see that it's been removed in their conversion to a Flash website. Anyway, add to the above the differing lengths of the heat exchanger injector (the tube leading into the HX from the pump) and I think that about covers the reasons why.

-- Dan

 
www.home-barista.com
back to top
 View Profile Visit website Link to this post
Tomcat
Senior Member


Joined: 15 Jul 2004
Posts: 79
Location: Frankfurt/Germany
Expertise: I love coffee

Espresso: QM Eliane, Bezzera B2000
Grinder: Mazzer Mini, Mazzer Kony
Posted Sat May 21, 2005, 11:43am
Subject: Re: Timing the cooling flush on E61 machines?
 

HB Said:

One reason for this difference is the size of their respective heat exchangers. Junior’s heat exchanger is much larger and a smaller percentage of its total volume is submerged in the boiler water compared to Andreja’s. The deeper a heat exchanger is submerged in the boiler water, the faster the heat exchanger’s temperature will rise since water conducts heat much more quickly than steam.

Posted May 21, 2005 link

Dan,

I don't know. Designing a semi-pro HX in a way that a similar percentage of its volume is outside the boiler water shouldn't be too difficult, I guess. And isn't there sufficient water convection within the HX that the heat capacity of the boiler water (i.e. its total volume) becomes the overriding factor for the heat transfer toward the HX water?

My guess is that the efficiency of the thermosyphon loop plays a role in all this. I know there is none in the Junior, but all commercial thermosyphon HX designs have so much more heat stored at the boiler/HX side of things that I presume they have much more thermosyphon action and a more stable dynamic behaviour because of their boiler and HX size.

Thomas
back to top
 View Profile Visit website Link to this post
showing page 3 of 7 first page | last page previous page | next page
view previous topic | view next topic | view all topics
Discussions > Espresso > Machines > Timing the...  
New Topics updated topics   New Posts new posts   Unanswered Posts new unanswered     Search Discussion Board search   Discussion Board FAQ faq   Signup sign up  
Not Logged in: Log In to Postlog in
Discussions Quick Jump:
Symbols: New Posts= New Posts since your last visit      No New Posts= No New Posts since last visit     Go to most recent post= Newest post
Forum Rules:
No profanity, illegal acts or personal attacks will be tolerated in these discussion boards.
No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum.
No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek.
No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum.
Who Can Read The Forum? Anyone can read posts in these discussion boards.
Who Can Post New Topics? Any registered CoffeeGeek member can post new topics.
Who Can Post Replies? Any registered CoffeeGeek member can post replies.
Can Photos be posted? Anyone can post photos in their new topics or replies.
Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts.
Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
Rocket R58 Double Boiler
Rocket Espresso R58 Double Boiler -  Everything you need for the perfect shot!
www.seattlecoffeegear.com
Home | Opinions | Consumer Reviews | Guides & How Tos | CoffeeGeek Reviews | Resources | Forums | Contact Us
CoffeeGeek.com, CoffeeGeek, and Coffee Geek, along with all associated content & images are copyright ©2000-2014 by Mark Prince, all rights reserved, unless otherwise indicated. Content, code, and images may not be reused without permission. Usage of this website signifies agreement with our Terms and Conditions. (0.501514911652)
Privacy Policy | Copyright Info | Terms and Conditions | CoffeeGeek Advertisers | RSS | Find us on Google+