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  • A better way to make espresso?

    Using mathematical electrochemistry a bunch of baristas, chemists and mathematicians suggest courser grind, 25% less dose, lower water pressure (6 ATM not 9) will produce a better and more consistent espresso.

    Anyone care to try? I’d give it a go but my pressure isn’t easily adjustable if at all

    https://www.abc.net.au/radionational...ience/11963970



  • #2
    Some good discussion in the other threads about this

    https://coffeesnobs.com.au/forum/cof...coffee-dr-karl

    https://coffeesnobs.com.au/forum/cof...odcast-dr-karl

    Comment


    • #3
      Yeah saw those but there was no call to action. Rather than flog a dead horse I felt it better to start a new thread, simply state what needs to be done and hopefully someone can give it a go and report back.

      Comment


      • #4
        I turned the pressure down on my ECM classica, but it settled in 8bar, no less. My coffee is the same, perhaps not enough change in pressure at the group.

        Less pressure might also reduce the chance of channelling. I think this experiment is really something the Decent Espresso Community should take on. Would be interesting to hear home-barista results...

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        • #5
          I have an R58 running at 6.5bar for 3 years, once I dropped it from it's factory preset I never went back. The difference to me, using a flat Mazzer Mini or the conical Niche was definately noticeable. I worked through brew temp and pull time adjustments (whilst still set at 6.5Bar) to try to achieve the optimum desired cup result. Most/all of the roast profiles I use are improved in the cup using the current 6.5Bar setting IMO - I do not do light roasts at the mo. 20.3g in 40g out in 40secs, VST. I'll try and find the original article that I read the idea.

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          • #6
            Originally posted by LauriG View Post
            Less pressure might also reduce the chance of channelling. I think this experiment is really something the Decent Espresso Community should take on.
            Decent advise people to start with a preset shot that only runs 6bar. I'm sure there's a bunch of discussion about it on the owners forum, which is unfortunately private to owners only.

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            • #7
              https://strivefortone.com/2016/05/18...essure-rehash/

              Skip to the paragraph headed "Ctrl-Alt-Delete" for the 3rd party OMG moments if you cant wade through the rest of the article. This article, and others to slightly lesser, started me on the 6.5bar road.

              Comment


              • Machvayne
                Machvayne commented
                Editing a comment
                Good read! Very interesting.

              • quester
                quester commented
                Editing a comment
                I often skip past links, tbh, but I was intrigued. It's Gold!!! Had a real "Ctrl-Alt-Delete" moment. I've been struggling away, at 9 Bar, and channelling far too often, trying to get that smooth, sweet, full bodied shot. Looking forward to changing my recipe and pressure to see where that leads. Thanks

              • SanderP
                SanderP commented
                Editing a comment
                That is a super enjoyable read.

                Cheers

            • #8
              I’ll admit. This may be the reason why I actually think the coffee I have at most cafes always taste bitter and/or burnt. Very seldom have I actually had good aromatic coffee with depth of flavour.

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              • #9
                The boiler and group head pressure on my Isomac has always been around 12bar since new. I figured while it's under warranty I shouldn't mess with it but maybe I should. I always get channelling around the rim but I thought that was that was just due to the tamper being just a tad too small (58.4mm tamper on order).

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                • #10
                  Originally posted by Superman View Post
                  Using mathematical electrochemistry a bunch of baristas, chemists and mathematicians suggest courser grind, 25% less dose, lower water pressure (6 ATM not 9) will produce a better and more consistent espresso.

                  Anyone care to try? I’d give it a go but my pressure isn’t easily adjustable if at all

                  https://www.abc.net.au/radionational...ience/11963970

                  Low bar shots are awesome - I wrote a profile for Modbar EP that went 3.5bar/6.0bar/5.0bar/3.5bar using an Indonesian SO and it was gorgeous. Two roasters I work for are requesting 7.5 - 8.5bar on their LMs (at the machine gauge). It’s a thing.

                  Comment


                  • #11
                    Seems so. My isomac always pulls at 12bar ever since I had it. I'm trying to see if I can drop it to 6bar.

                    Comment


                    • #12
                      My machine is set to 9.1 Bar and when I pull the shot the gauge drops to, circa 8.6 Bar. (May be lower, and is lower, of course, if channelling) I'm unclear when people are quoting what bar their machine is as to whether it is with the blank flush unit in, when the pump is first engaged or eg mid-draw?

                      Regardless, I had been intending to drop to 8.8bar (with the blank in) to see whether this reduce channelling, in conjunction with Sette 270Wi grinder. May just have to fast forward towards 7.5ish bar. Also interesting that, in that linked article, 19gm is recommended in 20gm VST basket. And 40 second draw!!!!! Tamping at 10kg.....Home Barista site still Rx 40Lbs and tamping the shite out of the puck??

                      The other thing that intrigues me is the role of pre-infusion. I'm intrigued that, when watching YouTube demos and reviews, most people have machines which are pre-infusion enabled and yet almost never use that function with their E61 GHs. They just go straight into pulling the shot. I thought the whole point of paying for that functionality was to then saturate the puck, to some extent, to gain the most flavour?

                      Comment


                      • #13
                        My 12bar is constant throughout the entire shot and the same if I have a blank in.

                        My research on pre-infusion revealed while it logically makes sense, it's very questionable if there is discernible taste difference in blind taste tests. That said I still (manually) do it.

                        Comment


                        • #14
                          Originally posted by quester View Post
                          My machine is set to 9.1 Bar and when I pull the shot the gauge drops to, circa 8.6 Bar. (May be lower, and is lower, of course, if channelling) I'm unclear when people are quoting what bar their machine is as to whether it is with the blank flush unit in, when the pump is first engaged or eg mid-draw?
                          People will be quoting the pressure with the blind filter in, as this is the maximum pressure that will ever reach the puck. The OPV is set to this value. If you are seeing a lower value it is because your puck is not as high resistance as a blind filter (not a bad thing), so there's no point only quoting the lower value as it only tells us about how finely ground your coffee is, not your machine settings. Quoting it with the maximum value gives more information about your puck.

                          Regardless, I had been intending to drop to 8.8bar (with the blank in) to see whether this reduce channelling, in conjunction with Sette 270Wi grinder. May just have to fast forward towards 7.5ish bar.
                          Just remember that a change in pressure will mean you need to find your feet again, so to speak. Don't only change the pressure, have it not do what you wanted, and change it back again. You'll need to have a play with your dose and grind as well.

                          Also interesting that, in that linked article, 19gm is recommended in 20gm VST basket. And 40 second draw!!!!! Tamping at 10kg.....Home Barista site still Rx 40Lbs and tamping the shite out of the puck??
                          The article that noonar linked above has been rattling around in my head since I read it yesterday. What follows is part a reply to what I've just quoted, and part thinking out loud as I continue to process it, I just had an Ahah! moment when thinking about how to reply to your comment.

                          The picture at the top of the article threw me a bit, but I think I've figured out what it's about. It's representing the uneven pressures on different particles within the puck (ner der). Why this matters though is the relationship between the pressure on a soluble material and how soluble it is. We have been told for a long time that higher pressure means more extraction, but this is often not the case (as evidenced in the article noonar linked and the one the article at the top of the page refers to). Why though? Because the pressure actually makes it harder when it's uneven. Think about a sphere made of sandstone, if you compressed that in a hydraulic press, then started spraying it with a high pressure water jet, bits of sand would come off. But as the sandstone kept eroding you would find that a column of sandstone between the two points of contact with the press would not be eroding as easily because the pressure compacting it gives it strength. It's easier for the water to go around the more compacted parts than it is for the water to push them out of the way. The same is true in a coffee puck, if there is uneven pressures on different particles of coffee or will be easier for the water to go around the high pressure areas and through the low pressure areas. Since, as we know, the degredation of the puck allows increased water flow this problem will get worse for a time, however once areas around the high pressure areas are dissolved perhaps the higher pressure will push into the lower pressure any they will even out somewhat, this reduced pressure on the less dissolved areas may lead to increased solubility. This all sounds like micro channelling.

                          Anyhoo... The reduced dose is to allow for finer grinding, which generally improves consistency of particle size. The 40s shot is the result of this. I remember when I first started reading up on espresso I got the impression that a 40s shot would taste of burnt rubber and charcoal, so pretty much never tasted one. I regularly have shots that run close to / over 40s as the desired shot. I've got a decaf bean at the moment that works best as a long slow shot. 20.5g in, 50g out, in about 39s. I always thought decaf was supposed to be short quick shots but this one doesn't work like that. The reduced tamping pressure is to get rid of the uneven pressures on different particles, which should improve the evenness of extraction. Recommendations of very hard tamping are common to beginners, it's easier to tamp hard consistently than it is to be consistently soft. The article even talks about removing the variability of tamping by using a Puqpress. Whether consistently hard is better than consistently soft is still with the judges I reckon. Personally I try not to tamp particularly hard.

                          The other thing that intrigues me is the role of pre-infusion. I'm intrigued that, when watching YouTube demos and reviews, most people have machines which are pre-infusion enabled and yet almost never use that function with their E61 GHs. They just go straight into pulling the shot. I thought the whole point of paying for that functionality was to then saturate the puck, to some extent, to gain the most flavour?
                          Preinfusion can do lots of good things, but if you just add or subtract it from a shot that is otherwise the same the "prewetting" type preinfusion of an E61 is unlikely to do a lot more than the natural preinfusion of all the space inside the group filling with water before building pressure. If you use preinfusion as something that will let you grind finer it might get better results (the Decent community is really leading this front). I guess most people are just doing preinfusion or not, not experimenting with grind when trialling preinfusion. I dare say you could list a lot of machines in the category of "most people have machines which are XXXXX enabled and yet almost never use that function"

                          This is all making me more keen for the last couple of parts to arrive for my BDB profiling mods... Keen to try out the lower pressure shots without leaving the machine unusable for my other third.

                          Comment


                          • #15
                            What a remarkable and insightful contribution level3ninja !! Wow.

                            So, I've started the process of pursuing these new settings and the results have, so far, been immediate and VERY worthwhile. Thanks for clarifying the Blind filter. I guess it's obvious but just needing to check. What I have done is lowered my machine to 8 Bar and, so far, getting close to getting the grind set for 19gm, 40 seconds and 38gm out, the gauge on my machine is fairly consistently showing 7.4 bar. Since lowering the pressure to this setting I have not had channelling or even those pesky little random spots that had a habit of appearing on my white espresso cup. The taste has improved significantly. I'm now getting the flavours the bean supplier described and realised it isn't just the sort of marketing hype you get on wine bottles - designed to ease your wallet and rob your palate!!.

                            So, With my ECM Technika Profi V PID Hx machine, plumbed in at circa 1.5Bar. I'm doing 10 sec pre-infusion showing 1 Bar on the gauge, 19gm in, 41 secs and 38.5gm out and showing, in this instance, 7.5 bar pressure. Getting rich smooth full bodied fruity chocolate taste with a slight licorice aftertaste, from the roast/blend being used today. [VST20g basket arrived this morning so still dialling in etc].

                            Now to work out the finer grind required, approx, so that I can adjust and dial in prior roasts more quickly.
                            Re Tamping pressure, I use the Decent V2 tamper. I think that is set for 20Lbs but there is no click so you can force it to whatever pressure you like. As you say, trying to be consistently soft, around that pressure, is my next challenge. At least I know the damn thing will be level, which has been my nemesis.

                            level3ninja I hope your work, above, doesn't get buried in the depths of blogdom here and that others have the chance to learn from your musings. Such generosity is very heartwarming. Thanks also to Superman for starting this discussion and noonar for the link and contribution.

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