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Trying to improve extraction with a new high end machine - some pointers please!

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  • #16
    Bit off track I think...

    OP asked about his kick-ass new GS3 - which would have come with VST baskets - yes Leonardo?

    Others will (and have) recommended to dose by volume. However it is a fact that if you do, when you change your grind you will absolutely change the amount of ground coffee in the basket too. This is why I never dose by volume, because you will end up effecting 2 parameters - not 1.

    If you are using the VSTs, it is very important to weigh, and dose in your VST to the prescribed weight + or - 1g (so get yourself some 0.1g scales. evilbay has lots that are cheap. I just bought 0-3000g 0.1g ones for $20 and they're great)

    To address your specific questions:

    If I weigh the dose, will I get a significant change in volume with changes in the grind?
    Not significant, but noticeable if you were doing say the 5c test. On the mini a change of one 'notch', if dose weigh is the same, will normally result in around 3-5ish seconds difference in the pour.

    How critical is it to achieve optimal fill using the screen imprint in the puck as a guide? Or is that overfill? The new basket does not have the ridge that I used to use with the old basket as a post tamp fill guide.
    Very uncritical. My advice - forget assessing your fill by the imprint on the screen, there are too many variables associated with the imprint for it to be a reliable method of dose assessment. Seeing a clear imprint on the puck, and the puck being very firm and dry after the shot is (usually) an overdose on a VST.

    The traditional double espresso basket dose is 14g? The higher the dose, the thicker the puck the lower the extraction percentage for which I am trying to compensate by coarsening the grind?
    A higher dose does not necessarily result in a lower extraction percentage, it depends on how long the shot pours for and how much coffee comes out. Extraction percentage is how much of the soluble bits of the ground coffee make it into the cup, and without a refractometer, you're just guessing. So don't worry about extraction percentage, be guided by taste.

    For our specialty coffees is it better to go 17g or even 22g or 14 g and get the extraction right? Can you up the dose and get the extraction percentage right?
    You can use whatever basket you want, but I would steer clear of the 7g single. Any double is fine (14g-22g), but the best way to try to get the "right" (there's no such thing as right and wrong, only tasty and not tasty) is to aim for 2:1 brew ratio (eg 14g in, 28g out; or 22g in, 44g out - both in around 25 seconds).
    Then once you have this, adjust your grind, OR dose, OR extraction time, one at a time, according to the taste you're trying to achieve.

    Aiming for 20% extraction? Does a 2:1 brew ration approximate this?
    Again don't worry about extraction percentage. Only way you can know this is by getting a refractometer, and I'd be recommending putting that $1000 into a grinder upgrade before a refractometer. It's way overkill.

    In a nutshell:
    - Get a 0.1g scale
    - Dose to prescribed amount on basket
    - Extract double the weight in the basket. Weigh the amount of coffee in the cup. Yes, measure liquid by grams, not mils
    - Extraction time of about 25 seconds
    - Taste, and adjust 1 parameter at a time until you have the taste you want.

    Have fun!

    Comment


    • #17
      Originally posted by chokkidog View Post
      Steve, Your post needs clarity and definition, has too much volume and not enough weight.

      ;-)..... sorry, couldn't resist....... but seriously, I've read it a couple of times and can't quite work out what you're

      actually meaning by it..... 2nd paragraph for example?
      Bames has rounded out what i meant pretty well.

      All of what I have wrote is just from my own experiences, with my own gear and tasting espresso out and about where ever I can.

      I acknowledge in a commercial situation one needs a fast repeatable routine to even have hope of making it. I have praise for the people willing to sacrifice some speed to try and get the best possible extraction for there customer though.

      I don't subscribe to the extremes of where these philosophies are going, ridiculous light roasts which have to be pulled long and loose to balance their still green nature. Does not mean there is no merit at all in the ideals. At the other end of the spectrum I did find myself going down that spiral of roasting darker just so i could use larger baskets, fill them up with what to me now seems a coarse grind and pull goopy shots all the time.

      I seek balance in all areas life and for me i think there seems to be a bit of a battle of extremes going from your David schomers et al ideals to the extreme thrid wavers with what i would call light for a filter roasts being pulled as lungo espresso. Maybe we can all meet in the middle some day and sing campfire songs around a turkish pot?

      Comment


      • #18
        Originally posted by Luke_G View Post
        I have stayed away from the whole "specialty coffee" circle jerk for a few years and upon reading all the forums and doing the rounds of all the new and "best" coffee shops i have found 2 major differences from 2 years ago.

        Melbourne "style" roast profiles.
        To me, this is F'n stupid and a waste of good coffee. I can not stand the taste of ultra light roasted coffees as an espresso based drink. Tastes sour, fruity and almost battery acid like. If i wanted those nuances, i would ask for a pour over brewed with a low temperature.
        Not sure if you're actually in Melbourne, but if you are, you may be interested in a place called "Brother Thomas". They advertise "Italian-style" blends for their espresso and I found them to be balanced, smooth and not at all third-wave-battery-acid-fruity.

        Comment


        • #19
          Originally posted by Steve82 View Post
          I would hazard a guess that most of the time when people complain about their shots being bitter, they are actually tasting under extraction, to much DOSE of coffee for the resulting shot, too much acids / bitters / flavours = assault on taste buds over powering everything else.
          The phrase "under extraction" gets thrown around a lot it seems.
          To me, it implies that the rate of flow was high relative to the rate at which solubles were extracted (resulting in a low concentration). This is independent of dose.

          What you are talking about is closer to the ristretto vs espresso concept (I.e. shorter extraction leading to higher concentration). It's not so much that the extraction is insufficient, rather that the dilution is low (as concentration in the cup decreases with shot duration).
          Last edited by MrJack; 12 August 2014, 06:46 PM.

          Comment


          • #20
            Originally posted by Luke_G View Post
            As you can see Leonardo, everyone has their own opinion.

            I have stayed away from the whole "specialty coffee" circle jerk for a few years and upon reading all the forums and doing the rounds of all the new and "best" coffee shops i have found 2 major differences from 2 years ago.

            Melbourne "style" roast profiles.
            To me, this is F'n stupid and a waste of good coffee. I can not stand the taste of ultra light roasted coffees as an espresso based drink. Tastes sour, fruity and almost battery acid like. If i wanted those nuances, i would ask for a pour over brewed with a low temperature.

            Scales & syringes.
            What is it with every would be barista telling you that you are not making a "correctly made coffee" if you are not weighing every dose and shot and running it through a refractameter.
            Don't get me wrong, i use scales from time to time and even weight a shot every now and again but not even this is completely repeatable.

            I know things change and we must move along with trends to suit consumer expectation but seriously, people need to read less magazines and trying to copy what 7seeMorespressblacko are doing and playing with their own individual hardware and coffees to find the variables. Taste it people... that's what is there for!
            I'm not telling you you're not making coffee correctly. The way you described making coffee in your reply was the exact correct way to make a triple riz. So if you like riz-bangers that's fine, but that's not an espresso, and the OP asked about making espresso.

            Ristretto is 1:1 brew ratio, espresso 2:1.

            Leonardo, if after comparing 2:1 brew ratio espressos on a few different beans to 1:1 brew ratio rizzoes, you discover you're on the riz train, then drink that!

            Comment


            • #21
              Originally posted by MrJack View Post
              The phrase "under extraction" gets thrown around a lot it seems.
              To me, it implies that the rate of flow was high relative to the rate at which solubles were extracted (resulting in a low concentration). i.e. This is independent of dose.

              What you are talking about is closer to the ristretto vs espresso concept (I.e. shorter extraction leading to higher concentration). It's not so much that the extraction is insufficient, rather that the dilution is low (as concentration in the cup decreases with shot duration).
              Its not about the speed of the extraction. Sound a bit like semantics coming into play. Maybe unbalanced extraction might be better ?

              There is a lot more taking place at toward the end of a shot than just dilution.

              Comment


              • #22
                Wow. The OP must be totally confused by now.

                Grab some training Leonardo. Dose and time are important, but it's also about consistency- what you do and balance of the shot. It's not hard, you just need some help with the training wheels.

                If you're in Melbourne, drop me a line and come in. We can fix this in 10 minutes and you won't need a pile of gizmos to make great coffee either.

                Chris
                Last edited by TC; 12 August 2014, 10:22 PM.

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                • #23
                  Originally posted by Steve82 View Post
                  Its not about the speed of the extraction. Sound a bit like semantics coming into play. Maybe unbalanced extraction might be better ?

                  There is a lot more taking place at toward the end of a shot than just dilution.
                  My point was that people seem to use the term underextraction to refer to a number of (quite different) phenomenon.

                  "Unbalanced extraction" isn't really better as a) it implies there is such thing as a "balanced extraction" (which really has no objective meaning), and b) it requires understanding of what is meant (I.e. it's jargon).

                  I'm guessing what you mean is that if you use a high dose and restrict the volume passed through the puck the result is a high concentration of chemicals which extract rapidly, and a low concentration of those which extract slowly, relative to thier concentration in the beans ( aka, a ristretto).

                  I'm curious to hear why you don't think it's about "speed of the extraction" (or rather, rate of mass transfer)?

                  Comment


                  • #24
                    Originally posted by Leonardo View Post
                    Normaly I would make a double shot espresso and so have started with the 17g basket. I have a Mini Mazzer grinder and am dosing by levelling off the grind in the basket rather than weighing the dose. Then I have been adjusting the grind to get a 60ml pour in 30 seconds.
                    Welcome Leonardo
                    Sounds like you're at a pretty good place already! Double basket, Mazzer Mini, fill, collapse once & level, tamp - 60ml in 30secs. Sounds A-OK to me for a doppio
                    You happy with the way your coffee tastes?

                    Cheers Matt

                    Comment


                    • #25
                      Originally posted by MrJack View Post
                      My point was that people seem to use the term underextraction to refer to a number of (quite different) phenomenon.

                      "Unbalanced extraction" isn't really better as a) it implies there is such thing as a "balanced extraction" (which really has no objective meaning), and b) it requires understanding of what is meant (I.e. it's jargon).

                      I'm guessing what you mean is that if you use a high dose and restrict the volume passed through the puck the result is a high concentration of chemicals which extract rapidly, and a low concentration of those which extract slowly, relative to thier concentration in the beans ( aka, a ristretto).

                      I'm curious to hear why you don't think it's about "speed of the extraction" (or rather, rate of mass transfer)?
                      If I want a slower more "ristretto" shot, I grind really fine and dose lower, generally its a shorter shot and reasonably well balanced.

                      Yep I take your point, the term is used for different situations meaning different things to different people. when Im saying under extracted, its subjective, if the shot is not balanced properly with to much bitter acids which extract quickly in the first part of the shot then to my subjective taste experience its under extracted. I realise within the current new paradigm there are refractometers in use giving some objective data as to what % of extraction correlates with it tasting "good " or balanced and if its out of these % its under or over extracted.

                      In terms of speed, I simply meant that it does not matter whether its a fast (20sec) or slow extraction(50sec) it can still taste under extracted.

                      Apologies for this thread swiniging off topic. To the OP, to me it sounds like you would benefit from using the ideas in post http://coffeesnobs.com.au/general-co...tml#post538087

                      If you have the time for some accuracy it your prep then why not give it a go...

                      Comment


                      • #26
                        Originally posted by Steve82 View Post
                        If I want a slower more "ristretto" shot, I grind really fine and dose lower, generally its a shorter shot and reasonably well balanced.

                        Yep I take your point, the term is used for different situations meaning different things to different people. when Im saying under extracted, its subjective, if the shot is not balanced properly with to much bitter acids which extract quickly in the first part of the shot then to my subjective taste experience its under extracted. I realise within the current new paradigm there are refractometers in use giving some objective data as to what % of extraction correlates with it tasting "good " or balanced and if its out of these % its under or over extracted.

                        In terms of speed, I simply meant that it does not matter whether its a fast (20sec) or slow extraction(50sec) it can still taste under extracted.

                        Apologies for this thread swiniging off topic. To the OP, to me it sounds like you would benefit from using the ideas in post http://coffeesnobs.com.au/general-co...tml#post538087

                        If you have the time for some accuracy it your prep then why not give it a go...
                        Acids are "sour"... not "bitter"

                        To quote from The Society of Sensory Professionals:

                        "Sour-Bitter Confusion

                        There is a phenomenon in the sensory world widely referred to as the sour-bitter confusion that commonly occurs among untrained assessors. This occurrence involves the assessor describing a sour sensation as bitter and/or a bitter sensation as sour, with the former being more predominant. This practice appears to be limited to predominantly English-speaking countries such as the United States, Great Britain, and New Zealand6. Debate in the past has centered on whether this confusion stems from a physiological disorder or simply a deficit in exposure to and training with sour and bitter tastes4,5,7.

                        Bitter and sour are two of the basic tastes and are found in a wide variety of foods and beverages to help balance the products flavor profiles. Compounds such as amino acids, peptides, esters, lactones, phenols and polyphenols, methylxanthines, flavonoids, terpenes, sulfimides, and organic and inorganic salts contribute to the bitter tastes in products such as coffee, tea, chocolate, and some fruits and vegetables2. Sour tastes are associated with hydrogen ions and organic acids and are found in such sour foods as jams and jellies, buttermilk, processed meats, sauerkraut, and other products1.

                        Despite different compounds contributing to the sour and bitter tastes in foods, several studies have recorded subjects frequently confusing the two terms when attempting to describe simple solutions made with sour and bitter substances. In a study conducted by Meiselman and Dzendolet5, 80 subjects tasted 10 mL aliquots of 15 mM sucrose (sweet), 50 mM NaCl (salty), 2 mM HCl (sour), and 20 mM KCl (bitter) and asked to describe the basic taste perceived for each solution. While all types of confusions were made, the sour-bitter confusion was the most common error made, occurring in 21.25% of the subjects (sour being called bitter more frequent than vice versa). The scientists then instilled a correction procedure in an attempt to train the subjects on the different tastes, but 35% of these subjects still made the sour-bitter error. These results led the researchers to attribute the sour-bitter confusion to a physiological defect analogous to abnormal color vision.

                        OMahony et al.6 conducted a large series of experiments in an effort to better understand the sour-bitter confusion. Some of the experiments were modifications of past work conducted3,4,5,7, while others were new designs. Of the new experiments, variations included using students in both the United States and Great Britain, inclusion of correction procedures when naming errors occurred, and varying the concentration levels of the simple solutions used in testing: sucrose (sweet), NaCl (salty), citric acid (sour), and quinine sulphate (bitter).

                        The results of these experiments clearly demonstrated the sour-bitter confusion with 13.3% of all 1629 responses for sour and bitter stimuli involving citric acid being called bitter and 7.7% of the responses involving quinine sulfphate being called sour. The authors offered several explanations as to why the subjects had difficulty distinguishing between sour and bitter tastes. One hypothesis is that the subjects have more cultural experience with sweet and salty foods than sour and bitter foods, allowing their perception of sweet and salty to be more clearly developed than sour and bitter. A second hypothesis is that subjects are more familiar with sucrose and salt in their pure forms than citric acid and quinine sulphate, again allowing the subjects to better develop their own personal concepts of sweet and salty versus sour and bitter. A third hypothesis involves the incorrect cultural labeling of typically sour foods as bitter, as in the case of bitter lemon. In regards to these hypotheses, the authors concluded that the sour-bitter confusion can be attributed to a lack in the clear understanding of the definitions of sour and bitter rather than a physiological defect6.

                        References


                        1 Da Conceicao Neta, ER, Johanningsmeier, SD, and McFeeters, RF. 2007. The chemistry and physiology of sour taste a review. Journal of Food Science. 72(2): R33 R38.

                        2 Drewnowski, A. 2001. The science and complexity of bitter taste. Nutrition Reviews. 59(6): 163 169.

                        3 Gregson, RAM and Baker, AFH. 1973. Sourness and bitterness: confusions over sequences of taste judgments. British Journal of Psychology. 64: 71 76.

                        4 McAuliffe, WK and Meiselman, HL. 1974. The roles of practice and correction I the categorization of sour and bitter taste qualities. Perception and Psychophysics. 16: 242 244.

                        5 Meiselman, HL and Dzendolet, E. 1967. Variability in gustatory quality identification. Perception and Psychophysics. 2: 496 498.

                        6 OMahony, M, Goldenberg, M, Stedmon, J, and Alford, J. 1979. Confusion in the use of the taste adjectives sour and bitter. Chemical Senses and Flavour. 4(4): 77 94.

                        7 Robinson, JO. 1970. The misuse of taste names by untrained observers. British Journal of Psychology. 61: 375 378."

                        Comment


                        • #27
                          And... how could a 50 second shot ever be underextracted?

                          Please explain.

                          Comment


                          • #28
                            Originally posted by Vinitasse View Post
                            And... how could a 50 second shot ever be underextracted?

                            Please explain.
                            If you grind coarse and overdose you can have low extraction yield (the water never extracts solubles from within the relatively low surface area to volume grinds) and all the 50 second extraction does is run past the already extracted surface of the coffee.

                            Comment


                            • #29
                              Originally posted by Vinitasse View Post
                              And... how could a 50 second shot ever be underextracted?

                              Please explain.
                              I know you like to include pre infusion in the total shot time....very large dose of lighter roasted coffee is hard to extract...extra long pre infusion, capable pump machine or lever..if the temp control is not spot on you can have a burnt bitter and overly acidic shot.

                              Your previous post highlights my original point...when most people find a shot bitter it is probably overly acidic and maybe under extracted. In such a concentrated form its perceived as bitter, if you dilute it to a long black it becomes easier to perceive as sour, more like warm lemon juice ect.

                              If someone perceives the shot as bitter, its bitter plain and simple, all the studies in the world don't change that. But that's not to say that I don't agree with them.

                              The easiest calibration for a home user is to zest a lemon, then the pith and then juice it and taste them. If you want to know what real bitterness is go and buy an Imperial IPA.

                              Comment


                              • #30
                                What Steve82 and Bames are talking about very closely parallels the findings of James Hoffman (who I think was World Barista Champion at some stage) and Ben Kaminsky who works with Matt Perger.

                                http://vimeo.com/28227701

                                https://www.youtube.com/watch?v=a-YI50dUC7g

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