Results 1 to 20 of 20

Thread: The Benefits of a Cooling Flush - Diadema Junior Plus

  1. #1
    Member
    Join Date
    Feb 2009
    Posts
    30

    The Benefits of a Cooling Flush - Diadema Junior Plus

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    It’s an epiphany… what a difference a cooling flush makes! I’m hitting the “god shot” almost on a regular basis and it’s more by accident than design.

    I’m a newbie HX machine owner (Diadem Junior Plus) and had read article like this http://www.home-barista.com/hx-love.html but it didn’t really sink in until the last few weeks… when it was all about grind, dose, tamp. Not Flush?

    I’m wondering if it’s peculiar to my machine (which constantly sits on close to 1.2 bar). Does the boiler pressurestat need to wound down a notch?

    Any way, I find that while I’m dosing I’ll start the flush which usually goes for about 20 to 25 seconds, stop the machine, polish off the tamp, then load, and then start the extraction.

    Does anyone else have a similar ritual – or something completely different? I would be really interested in hearing about it.

    Merr1

  2. #2
    Member
    Join Date
    Dec 2008
    Posts
    42

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    This is very normal. Every(?) HX requires a cooling flush - especially after the machine has been on for a while.

  3. #3
    Sleep is overrated Thundergod's Avatar
    Join Date
    Jul 2006
    Location
    Sydney
    Posts
    10,496

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Quote Originally Posted by 64617269757368000 link=1255257134/1#1 date=1255261617
    Every(?) HX requires a cooling flush
    Mine doesnt any more since it had its last service by Di Bartoli.

  4. #4
    Senior Member ozscott's Avatar
    Join Date
    Jun 2006
    Location
    BRISBANE
    Posts
    1,998

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    I think it depends on settings. A big commercial will require it if left sitting for more than it would in a busy coffees shop at peak time even with the pressurestat down a little. I have pre-programmed 2 of the 4 buttons on each groups pad for different cooling shots. However back to back shots do not require a flush with my set up.

    Cheers

    PS. By having the same flush volume each time when the machine has been idle for a while you easily achieve very good consistency

  5. #5
    Senior Member GregWormald's Avatar
    Join Date
    Jul 2007
    Posts
    2,286

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    My Junior EXTRA was requiring quite a long cooling flush with the pressure running at 1.3-1.4 bar.

    Since I rarely make more than 2 shots at once I dialled the pressure down to 1.05 bar and now I only need to flush enough to warm the espresso cup (about 60 ml) if it has been idling for a while.

    My previous Junior was set so the maximum pressure was just under .9 bar and didnt need flushing at all--if anything it needed a warming flush!

    Greg

  6. #6
    Senior Member
    Join Date
    Nov 2007
    Posts
    131

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    I have Giotto PP - do i need cooling flush??

    argon

  7. #7
    Senior Member
    Join Date
    Jul 2006
    Posts
    434

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    "I have Giotto PP - do i need cooling flush??"

    If you get "flashing", hissing and boiling as seen on this
    video

    http://www.home-barista.com/tips/when-is-end-of-hx-water-dance-t12068.html

    then yes.

    I reviewed what I was doing a few days ago, and found that
    I was actually flushing a bit too long, which wasnt helping
    the shots.


  8. #8
    TC
    TC is offline
    .
    Join Date
    Oct 2004
    Location
    Melbourne
    Posts
    14,665

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Quote Originally Posted by 695C4B4979415C434F424A2E0 link=1255257134/4#4 date=1255298822
    My Junior EXTRA was requiring quite a long cooling flush with the pressure running at 1.3-1.4 bar.
    Hi Greg,

    Bizarre that your machine was running at 1.3bar? Should be more like 1.1 bar and you should only require a rinse. Might be worth getting it checked to ensure that thermosyphon restrictors are in place.

    Thermosyphon restriction and Scace calibration can make most HX machines run beautifully- except the ones with poorly designed HX systems.

    Chris

  9. #9
    Senior Member GregWormald's Avatar
    Join Date
    Jul 2007
    Posts
    2,286

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Thanks Chris--adjusting it has made all the difference. It works beautifully at just a tad over 1.05 bar, and the flush is just enough to heat an espresso cup, and only after idling for an hour or so.

    I too was surprised that two machines, only a few serial numbers apart could be so differently adjusted--one very cool, the other hot. I guess its all in the set-up.

    Greg


  10. #10
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    16,775

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Hmmm....

    My DJE runs beautifully at a nominal setpoint of 1.0Bar (On at 0.95Bar, Off at 1.05Bar). barely any cooling flush needed at all, even if sitting idle for an hour or more. Originally, the p/stat was operating between 1.0 and 1.1Bar but seemed to settle down after a time to the above setting and thats where it has stayed ever since.

    Probably the most Ive ever needed to flush would be 60ml at worst but since the p/stat settled a bit, probably a 30ml flush is all thats needed to pull it into line. Steam quantity and quality has remained excellent....

    Mal.

  11. #11
    .
    Join Date
    Aug 2004
    Posts
    2,312

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Interesting discussion.

    My personal feeling is too much cods wollop is said about cooling flushes in general. Of course that is only my opinion.....

    The danger with cooling a machine down to a point where it doesnt need one (cooling flush) at all even after it has been left standing indefinitely, is it may well mean the machine has been over cooled and will underextract coffee under normal conditions of use.

    And of course conversely, a really long cooling flush means the machine is probably running too hot.... (and probaly set up for the Italian market withiout regard for other markets to where they are exported).

    Meaning, a happy medium (in my opinion) for home use (which is little use for *machines that are designed to operate continuously ie, not being used for the purpose originally intended/designed) is where you may have a small cooling flush that dissipates easily and pretty much as Mal above has stated!

    The mass of the group (on E61 machines) is kind of like a radiator in reverse....it is there to make sure the brewing water does not cool off too much on its travels from the heat exchanger to the grinds in the coffee filter, so it is there to stop the possibility of under extraction in continuous use. If you cool it too much so as not to have to do a cooling flush at all, it may not keep the right amount of heat up to the brew water or may even cool it down....

    As others have said in a round about way, its all in the total package of the particular machine, and any Diadema machines imported by my company are set up extremely well in fact dare I say it, I have been tweaking and doing signature specs for many years and actually taught others that now follow......

    A machine that has been set up well (internally) from the beginning, will likely repond to changes in the running pressure (via the pressurestat), affecting cooling flush and brew temperature. Machines that are running way too hot or way too cool (ie not set up well enough internally on the production line), will not respond to changes made at the pressurestat. The pressurestat in the end only allows for minor adjustments in the above.

    Notwithstanding any of the above there are plenty of brands and models that have been imported into the country over the years that are incorrigible / recalcitrant coffee burners (run far too hot) and no amount of pressurestat tweaking will do anything...but they are not the subject of this discussion.

    I am not into giving away my hard earned expertise and therefore am not willing to discuss internal set up any *further. *

    The best advice I think....is to stop thinking & reading too much and enjoy your machines! That means you need to learn the management strategy for how to get the best out of it. In many instances, you can learn that from your retailer.

    Regardz,
    Attilio
    very first CS site sponsor.


  12. #12
    Member
    Join Date
    Jul 2007
    Location
    Melbourne
    Posts
    87

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    My GPP sits at pretty much dead on 1.1 bar.

    Like your machine Mal, mine barely requires any cooling flush at all. In fact I generally dont bother. If I need to warm glasses, I use the hot water tap. Steady as a rock.


  13. #13
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    16,775

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Quote Originally Posted by 7D495E48536478545D5D5E5E3B0 link=1255257134/10#10 date=1255387656
    The best advice I think....is to stop thinking & reading too much and enjoy your machines! That means you need to learn the management strategy for how to get the best out of it. In many instances, you can learn that from your retailer.
    Well said Attilio.... [smiley=thumbsup.gif]

    After all, that is why we all bought machines of this calibre, to enjoy them and what they produce. Love my "Extra".... 8-)

    Mal.

  14. #14
    A_M
    A_M is offline
    Guest
    Join Date
    Mar 2006
    Posts
    6,381

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Quote Originally Posted by 032E2A262B470 link=1255257134/12#12 date=1255421648
    Quote Originally Posted by 7D495E48536478545D5D5E5E3B0 link=1255257134/10#10 date=1255387656
    The best advice I think....is to stop thinking & reading too much and enjoy your machines! That means you need to learn the management strategy for how to get the best out of it. In many instances, you can learn that from your retailer.
    Well said Attilio.... [smiley=thumbsup.gif]

    After all, that is why we all bought machines of this calibre, to enjoy them and what they produce. Love my "Extra".... 8-)

    Mal.
    The retailer... Choice of words... Sponsor / Retailer is more correct ;)

    Most of the plain retailers cause more issues...

  15. #15
    Member
    Join Date
    Feb 2009
    Posts
    30

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Quote Originally Posted by 4E5B52424E5555210 link=1255257134/3#3 date=1255296536
    PS.By having the same flush volume each time when the machine has been idle for a while you easily achieve very good consistency
    Good point... Im steadily incorporating this into my routine.

    Thanks

  16. #16
    Senior Member
    Join Date
    Jan 2009
    Posts
    264

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Quote Originally Posted by 7971666625140 link=1255257134/0#0 date=1255257134
    I’m wondering if it’s peculiar to my machine (which constantly sits on close to 1.2 bar). Does the boiler pressurestat need to wound down a notch?


    Any way, I find that while I’m dosing I’ll start the flush which usually goes for about 20 to 25 seconds, stop the machine, polish off the tamp, then load, and then start the extraction.

    YES ..... I have the same machine ,..... it was on 1.2 bar , and I wound it down to 1.05 , then back up to 1.13 (approx) when the p/stat clicks off ( it still continues to rise for a bit beyond that ).....and it could come down a tad more..!!!


    That flush is excessive ....... mine are usually 4-6secs, and Id be guessing about 30ml...... That more or less correlates to what Mal said at 1.05 you can almost get away without a flush at all.

    Ill probably drop mine to 1.1 after Ive had it 2-3 months

    All the best , great machine , enjoy !!!!!!

    Greg


  17. #17
    Senior Member
    Join Date
    Jun 2008
    Posts
    1,520

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    i dont have a Diadema this is my 7L Brugnetti HX
    This may not be a super scientific way to measure but i thought i would have *a look and see what temps it was making. I tried to take the temp picture in the middle of the 30ml shots using the volumetric button
    normally prior to making a shot while filling the basket i would run a double shot to "cool"

    the experiment tells me i should be cooling about *a double shot prior to pulling my coffee. *

    BEAD TC under the dispersion screen I was just making water shots


    at rest after 25 mins from "turn on"


    single cooling shot


    2nd shot 10 secs later


    3rd shot 30-40 secs after prior shot (about the time to reload another shot?)


    at rest 5 mins later


    1st cooling shot


    2nd cooling shot


    3rd shot 10 secs later (where i would have made the coffee)


    at rest 15 mins later (after shower)


    1st cooling 30 mls (was splurting out the GH)


    2nd 30 cooling


    3rd "coffee shot" 10 secs later


    4th shot 3 secs later (just to see)

  18. #18
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    16,775

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Interesting set of numbers there Leeham.... 8-) :)

    If you own a CoffeeSnobs Thermologger DMM, you could collect all of this info as a "live" data set for later study and charting. Should reveal a truer picture of the thermodynamics going on....

    Mal.

  19. #19
    Senior Member
    Join Date
    Jun 2008
    Posts
    1,520

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Thanks Mal,

    I knew the machine does get a bit hot if let sitting as i get the splutter splutter and have always ran a bit of a flush in my pre shot prep anyway.

    I was surprised it hit the 93 number well, it ranged a few deg in each shot but its no fancy thing. The TC may have a sligth error it was reading 99deg in a pot of water and 1deg in ice cube glass.

    these PIDs i have do have a mini usb plug in the side but not sure what for, will need to read the spec sheet again. Might be for uploading set points etc?

    Made me think if you have a HX it is worth a go and might give you and idea of the length of time you may or may not need to flush.

    As Attilio said but, dont read to much into it enjoy your machine :)
    I am uber happy i can make a coffee in my PJs at 7am about as good as 95% of the coffee shops out there.

    Leeham

  20. #20
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    16,775

    Re: The Benefits of a Cooling Flush - Diadema Junior Plus

    Quote Originally Posted by 666A636E6E670B0 link=1255257134/18#18 date=1255512921
    As Attilio said but, dont read to much into it enjoy your machine :)
    I am uber happy i can make a coffee in my PJs at 7am about as good as 95% of the coffee shops out there.
    Absolutely mate,

    All interesting from a purely geeky point of view though.... ;D

    Mal.



Similar Threads

  1. Cooling Flush On A VBM Domobar Jnr?
    By JJJ in forum Brewing Equipment - Pointy End ($1500-$3000)
    Replies: 8
    Last Post: 7th November 2011, 09:41 PM
  2. Cooling flush on em6910
    By acoggins in forum Brewing Equipment - Midrange ($500-$1500)
    Replies: 3
    Last Post: 11th February 2009, 09:06 AM
  3. Cooling flush
    By jimmyb in forum Brewing Equipment (non-machine specific)
    Replies: 11
    Last Post: 31st May 2007, 01:33 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •