Consistency versus Experimentation: The Quest for Better Results - Page 2

Beginner and pro baristas share tips and tricks.
DaveC

Postby DaveC » Nov 30, 2018, 8:07 am

Jake_G wrote:1. What indicators do you look for in a given shot that would suggest that you should increase the brew pressure? How about decrease? Or what makes you think to try a declining profile versus flat?

2. For instance, there's good consensus around brew temperature and roast level. Dark roast, cooler brew temp. Light roast, higher temp.

3. Likewise with grind level and what used to be dose, but now can be preinfusion duration. Darker roasts have historically been coarsely ground and up-dosed, with lighter roasts initially ground fine and down-dosed, but now simply ground fine and softened with a either a long slow preinfusion or a soak phase or some combination of the two. This allows some of the classic rules to be bent if not broken. But what about peak brew pressure? Lets say you have a grind and dose that you like with a given brew temperature and profile. What makes you think "that was great at 9 bar for the peak, I bet the same shot would really shine at 7 bar."? What about 10 bar? This is something I really haven't thought much about, but am ready to dive into now that I have so much more control over the rest of the extraction. My machine has been set at 8.5 bar with my 8mm non-restrictor for the last 5 years. It's likely time for me to figure out what other pressures taste like, but I'm curious if there are some conventions that might guide the would-be traveler in their quest?

Cheers!

- Jake


The area is complex, so much so that I have few answers after literally years of experimentation.

1. The shot doesn't always give obvious indicators....it's unfortunately a taste thing. However because grind can change (especially if you profile with a slow ramp up), you have to wonder what effect that can have.. The only thing I know for a fact is that straight 9 bar, 8 bar etc.. probably isn't the best profile. Any flat profile was because that's what could be done, not because it was best. A lever gives a declining profile, but again, because that's what it does, not because it's best. The development of a pressure for extraction was a consequence of the technology used. We have different tech now and can do different things. it might be 10 or 11 bar at the beginning of extraction is optimal, reducing as the shot progresses, it might be lower pressures entirely are better.....I don't know for sure, but I have some ideas.

2. There might be good consensus, but again that doesn't make it right or definitive. That consensus was largely reached based on machines that cannot do what they do today. I have experimented with both higher and lower temps on light roasts and I find that too high a temp simply brings out undesirable notes, in the same way as it does on dark roasts. So I buck the trend, but I have to go by taste. I do find that pressure and duration of extraction can make a big difference though. light roasts seem to like a longer extraction and a good preinfusion. I think people often vary temperature to try and make up for a suboptimal roast. I usually extract at 93.5C on my machine. If I change it I will sometimes go as high as 94.5 or as low as 92.5...not often though. Can people taste 0.5C difference, not usually. Roasters should also be creating roasts that extract well at the widest range of temperatures.

3. Grind level again is really tricky. In the past machines were simplE and a certain grind level was required. Machines and grinders have moved on a bit and like everything else grind can vary with the rate we extract pressure, bloom phase, max pressure and extraction time....which of course doesn't have to sit within a rigid zone of 22-32 seconds or whatever. Much longer extractions can be done if desired.

It's hugely complex and I think the whole area needs to be revisited, if it is I think will also affect the way roasters roast. I'm hoping the next wave in coffee is going to really rethink how we produce shots, rather than the rather simplistic dark vs light roasting.

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Jake_G

Postby Jake_G » Nov 30, 2018, 9:29 am

bluesman wrote:But I'm a bit concerned that so many posts on the topic start with unhappiness over the current state of the author's brew. It often seems that only a minority of HBers are actually happy with the espresso they're making. This makes me wonder if they know good espresso from bad and if they actually like it or are feverishly trying to make it something it's not.

I can assure you, I'm quite happy with mine, but I hear what you're saying. I'm sure a good deal of it comes from how the majority of folks use forums, which is to solve problems. How many new members join just so they can get help with their specific issue, and then never really join the community? How many more non-members find their solutions in the archives of HB while searching for answers and consequently never join. Not too many folks likely join HB just to say:
Random Happy Home Barista wrote:Hey everyone!
I think my espresso is pretty tasty.

Thanks!
-RHHB

It's another avenue where having my Jekyll and Hyde machine is a great tool for grounding my senses. If I think I like something that I'm getting relative to preinfusion of profiling, every now and again, I prepare a shot on the stone stock right group. Sometimes I'm surprised by the difference and occasionally (more often with darker roasts) I prefer it! I'm trying line pressure preinfusion with Malabar Gold right now on the stock group and found side by side comparisons to Slayer shots with 15-20 second pre brew on the profiling group to be very interesting. I need to try a few more before I have a consensus on my preference. Being able to compare and contrast helps make educated guesses as to what might bring out the best in a bean, but even so, the extraction space on a manual profiling machine is MASSIVE. There's something to developing a technique and getting some intuition in general, because my espresso has improved tremendously in the last year to the point where I don't know how I could produce consistently poor results now without intentionally trying. Varying levels of good? Sure. Preference of one technique to another? I think so. But gone are the days of drowning every shot in milk because "clearly espresso is too intense, bitter, sour, etc... to be enjoyed straight." Some of the best advice you'll find on this site is to go taste good espresso! I think another gem is to have other folks taste yours. We can live in a bubble where we think everything we make is magic. No better reality check than to go taste some seriously good espresso (if you can find it!) with a buddy and then with the same buddy, compare notes with what you're making.
I'm also amazed at the meticulous attention to microdosing brew temp, tamping pressure etc that is paid to the process by people for whom attention to basic cleanliness, maintenance, etc might yield a greater improvement in the cup. A glance at the PFs, baskets, wands and even the machines themselves often makes me say "no thanks".

I'm moving towards weighing what I do, but using it more like a cooking recipe, rather than going ballistic with sceintific precision and rigor. I've gone from 17.5g to "around 17.5-ish". I document it, because if I want to down-dose after tasting something, it's good to know if sometging closer to 17 resulted in something that I should try dosed down a bit or was it closer to 18, but I eyeball the level of my dosing cup (14g Faema ridgeless basket that easily holds 20g of Monsooned Malabar whole beans...) as it sits on the scale and get it close. I dont pick individual beans so micj any more, but i do find myself reaching on occasion :wink: Precision is for when I'm using the refractometer to test something. Otherwise, I'm cooking and I tend to ebb and flow with the recipe as I get to know a coffee...
With respect to cleanliness, I hear you! I'm sure there's a little spatter on my front panel in more than a few of the photos of my machine, but it gets cleaned well after every session and gets a thorough internal scrubbing regularly. In fact, I'm eyeing an IMS screen simply so I don't have any spots where crud can hide between the mesh and the perforated stainless, which does happen on the stock screens.

Cheers!

- Jake

Cwilli62

Postby Cwilli62 » Nov 30, 2018, 10:17 am

I'm really enjoying this thread. Unfortunately, I don't have much to currently add to the discussion, as I'm learning (and waiting to get a machine capable of pressure profiling).

Just wanted to say thanks and that I believe these parameters and the status quo in general are well worth discussing/experimenting with.

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Jake_G

Postby Jake_G » Nov 30, 2018, 9:35 pm

CwD wrote:Personally I quite love my espresso. I enjoy it and am happy with it in the sense it's some of the best I've had.

Good to hear from you, Mitch!
But the "best I've had" or even if I could claim "best in the world" isn't enough, I won't be satisfied until there is literally no way operating within the laws of physics to wring even the slightest bit of extra quality out of it.

I'm curious about how this could be achieved. Obviously, pulling the shot until purified water leaves the puck is one way, but that brew would lack strength. Could you then distill the resulting beverage until TDS was again in espresso range and have your espresso and drink it, too? I wonder if there exists a way to do this while retaining the aromatics that give espresso so much of its character...
And I know from experiments in other brewing methods that there is undoubtedly more good stuff in the coffee I'm leaving behind. That to me is completely unacceptable. It's not just a drink to me, but a scientific challenge to achieve perfection through any means necessary.

I see a miniature roller mill with a densifier in your future :D
I don't think a single pass exchange from the puck to the water will ever get you what you're after, though it can certainly get better with improved methods. To reach the your goals of maximum extraction in a high TDS shot of espresso, you would need - at the bare minimum - a way of forcing out the water that remains in the puck along with all the disolved solids contained in that water. One such solution could be a 2 stage machine with an infusion stage where water is pumped in using typical espresso machine tech followed by an extraction phase that pumps air through the puck to evacuate the solids-laden water within the puck. Even better would be a method of recirculating the water through the ground coffee powder until the water was saturated and then extracting the liquid from this slurry. Turkish coffee plus pressurized water plus centrifuge? Such machines could be quite successful at increasing extraction yield, but maybe that's best left to a separate discussion?
Should perfection ever come effortlessly, there's still lots to enjoy that is already the primary focus for me in coffee. Exploring regions, farms, varietals, processing, etc. (exploring roasters/blends very intentionally left off, imo the job of a roaster is strictly to make the coffee is as soluble as possible without imparting the slightest hint of their own flavor) Can't be quite as extreme with it as I am with brew where I usually only have about two brews worth of a coffee since espresso dial in is more intensive, but still very very very rarely like to have more than one bag of the same coffee.

Interesting take on roasting. I've never thought put too much thought into how to quantify solubility, but it's obviously a thing. If there were a roast level vs solubility graph, would there be an inflection point in the curve where you would say a roast has "done it's job"? Or is it just a matter of "no roasty taste, please"? I've definitely gotten some of those roasts that went too far and made it impossible to enjoy the results. These weren't just darker than my tastes preferred, though. They were burnt. Craters and all. Ick.

Cheers!

- Jake

CwD

Postby CwD » Nov 30, 2018, 10:38 pm

I'm not looking to get everything out of a coffee, just everything good. From some of my absolutely amazing Turkish brews, I know that's at least ~28%, significantly higher than my highest yield shots. But Turkish is far too weak to satisfy the espresso spot. I essentially want to pull shots with 15-20% tds and 28-30% exty. I think it could be doable with a perfect enough grind. Some like CERN level precision stuff. I do think burrs will need to be abandoned entirely in favor of something that can create particles that are exactly identical, and possibly baskets designed to provide a structure to allow water to penetrate a puck of entirely microscopic fines. Having to have coffee provide that structure will inherently lead to uneven extraction. In essence every single particle being orders of magnitude smaller than Turkish grinds and something inert making sure the water can reach it all. Can optimize other things on the way (finding ideal flow profiles, temperature, etc), but our gear is fundamentally not good enough yet and I'm annoyed by how stagnant it is.

As for roast, I think everything above the Nordic style roasting is imparting too much of the roasters own flavor. Not just roasty, I want no notes imparted by roasting. So no caramels, etc. Nothing against people who prefer something the roaster has altered, I just personally prefer ones who only seek to bring out what's in the seed without their own touch.

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Jake_G

Postby Jake_G » Dec 01, 2018, 4:17 pm

happycat wrote:What I am seeing is a need for an integrative review of the HB literature. Lots of reports and knowledge here over many years but it remains disparate enough to not be established, challenged and revised.

Agreed.
Any thoughts on how to accomplish this?

An integrative review provides a thorough summary of the current state of knowledge on a set of key topics. That summary makes it clear what needs to be checked or fleshed out in the future.

Hmm,
Are you envisioning a sort of landing page with links to recent discussions, or perhaps a FAQ? I like the idea but wonder how we could implement it within the framework of the forum...

The social media habit of simply appearing and asking for personal help on every repeating topic without researching, reading, setting context, etc. certainly doesn't help much.

That's what separates a community of practice from a hobby site I guess.

Indeed.

I'd love for this discussion to help facilitate the integrative review process with help from contributors such as yourself. I could keep the first page updated with a link to subsequent review topics (future posts within this thread) and we could spend some time digging through the existing literature and placing it in context, along with links to current discussions that help frame the current state. Maybe it's a pipe dream, but getting the learnings of the past juxtaposed with today's application of technology in an accessible place would be a great accomplishment and something I'm excited to help with if at all possible.

Cheers!

- Jake

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Jake_G

Postby Jake_G » Dec 04, 2018, 9:17 am

another_jim wrote:It's not a mistake; it's an experiment. :D

I completely agree, but how do we coach folks on how to craft an experiment well?

Going for consistency presupposes that 1) there is a best practice for whatever coffee and setup you have, 2) that you know it. I rarely believe the first and never believe the second, since I usually run out of the coffee I'm pulling before I have a handle on it.


So, do you tend to start with some "baseline" pull based on assumptions and educated guesses as to what you think might make a new coffee shine and then go from there with "the basics"? To DaveC's point, even brew pressure is hardly a given these days. My default was line pressure preinfusion for the better part of a year because my pours were so much more consistent (there's that naughty word again...) then of course I was moving grind around to get the timing correct but generally leaving dose alone. My machine is headspace limited, so grinding coarser and dosing more wasn't a great option for me with my current basket selection. "Why dose more than 18g?", I said. It wouldn't fit in my basket anyway.

Fast forward to needle valve based flow profiling and I see even less reason to muck about with dose. If I hit a shot hard with the valve opened wide (I can really let it rip if I turn it 3 full turns out to wide open, but almost mever do...), I can choke the machine no problem with a grind that behaves just fine with a 15 second pre brew at peak of 2ml/s. So if I want to grind coarse, I just increase the flow rate during pre-brew until the pour "looks good". I'm generally rewarded with what you would expect from adjusting the grind. If I also stop the shot shorter, I get a more punchy shot. Just as if I bumped up the dose, but obviously my yield is correspondingly less than if I had bumped the dose up and left the yield alone, so I guess there's a reason to get a bigger basket, but for me the real benefit tends to come from grinding finer and not needing to down dose to get the pour I'm after. I'm not really intending to turn this into a conversation about profilers, but one of the things I'm interested in is consistency around dose. With a profiler, I can't think of why you'd change your dose following the classic guidelines.

In fact, I tend to go the other way entirely. Finer grinds inherently compress more and thus you can fit a larger dose of a fine ground coffee into the basket than you can a coarse grind. Thus I tend to dose to the nickel test standards. If I have just a wee bit of headspace, I'm generally good. Interestingly, if I dose too low for a fine grind, the puck tends to stick to the shower screen. Bumping the dose up a half a gram or so seems to "fix" this annoyance. If I go coarse, I have to drop the dose because less fits in the basket. This is counter-intuitive, but switching to a more aggressive pre-brew flow rate seems to completely address the issue of shot time, if we even care about shot times any more...

Think about where you are on this spectrum; and the question answers itself.

I'm clearly with you on the experiment aide, but I don't think that I have any great skill set when it comes to my palette to help guide the right moves. I'm pretty good at the mechanics of it and I can make a shot do what I want it to do in terms of manipulating the inputs to get desired outputs, but I struggle with exactly what I'm tasting and how changing the inputs affect specific qualities of what's in the cup. I don't think I'm entirely alone here, but it could be that every coffee is so vastly different that there are more exceptions than rules. I'm not unhappy with my espresso in the slightest, but I do find the current range of options for extraction daunting to say the least. It would be interesting if I started logging shots, (sorry, too ADHD to have have already started doing this!) and found if there was a cadence to my experimentation that I could take advantage of, or emphasize. Most of the tine with lighter roasts im just having too much fun exploring the bright, juicy and fruity flavors to care much, but I think a "tour guide" could really help me hit that "Wow!" spot quicker amd more consistently before I run out...

Maybe this is all just gibberish, and I know how low Jim's tolerance for nonsense is, so I'll leave it there ;)

Cheers!

- Jake

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another_jim
Team HB

Postby another_jim » Dec 04, 2018, 12:21 pm

Jake, I have no unshared secrets for dialing in shots quickly. Like everyone else, I'll start on the coarser grind, cooler shot end for darker roasts, finer grind, hotter shot end for lighter roasts and go from there. I brew coffees before I pull them to get an idea of what they taste like "unplugged." With the Bianca, I'm trying out 1:5 brew ratio, demi-tasse shots (?) as the unplugged base line.

Experimenting is different from dialing in, and for me it's more "meta." That is, I do an experiment to see if I need to change my expectations and SOP. This means I'm testing whether I'm screwing something up or am working based on bad assumptions. This usually comes down to testing two different ways of doing things with several different coffees over enough time that I'm personally sure I have it right.

Sadly, most of my experiments end inconclusively, with me not sure if I've grasped the real issue. A good experiment presupposes an insightful problem statement; without that, you just get the usual "our survey shows" blather. I recently thought that arguments about roast levels and extraction could be settled using distinctiveness as a standard (i.e. how easy it is to tell different coffees apart). But all my experiments along these lines were been a bust so far, with only small, non-repeatable differences. So I need to rethink the concept rather than "collecting more data." (sorry, as a sociologist, I spend a lot of time rolling my eyes at nonsense with numbers attached, a disease that's pandemic in the food and foodie sciences as well)
Jim Schulman

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Jake_G

Postby Jake_G » Dec 07, 2018, 1:00 am

walt_in_hawaii wrote:With a topic so variegated I sincerely doubt there will be a strict concensus of opinion or methodology.

Indeed. It's nice to see some ideas of the general approach nonetheless. Even if some of those people have an unnatural hatred of God's slimy, hoppy and green gift to the trees (I think it's jealousy of their long and sticky tongues and potentially alkaloid-enriched skin...).

I think the most obvious way to resolve this is what has already been going on in small scale here, meetings between small groups so that a greater segment of people can be exposed to the same flavours and have their tastes 'tuned' to provide some consistency or base across all the various levels of experience and exposure to equipment. Establishing a reference floor is important in what would otherwise be methodology descriptions floating around out on the aether.

Again, I agree. Taste together. Taste the same beans separately. I'll taste yours if you'll taste mine... I do believe this level of sharing ideas and flavors is foundational, and drives the concept of recreating something we have enjoyed as well as augmenting to see what else it has to offer. It's all enjoyable.

Cheers!

- Jake

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Jake_G

Postby Jake_G » Dec 08, 2018, 3:39 pm

DaveC wrote:The area is complex, so much so that I have few answers after literally years of experimentation...

I was afraid of that...


1.The only thing I know for a fact is that straight 9 bar, 8 bar etc.. probably isn't the best profile. Any flat profile was because that's what could be done, not because it was best. A lever gives a declining profile, but again, because that's what it does, not because it's best. The development of a pressure for extraction was a consequence of the technology used. We have different tech now and can do different things. it might be 10 or 11 bar at the beginning of extraction is optimal, reducing as the shot progresses, it might be lower pressures entirely are better.....I don't know for sure, but I have some ideas.

I am inclined to try a rising pressure profile purely because it is the opposite of natural. It is also somewhat difficult to pull off smoothly with a manual profiler since it nearly requires a soak phase to keep pressure from rising once the puck is saturated. No doubt it can be done and well-executed but not with near constant modulation of the flow. It'll probably be terrible, but why not try?

2. There might be good consensus, but again that doesn't make it right or definitive. That consensus was largely reached based on machines that cannot do what they do today. I have experimented with both higher and lower temps on light roasts and I find that too high a temp simply brings out undesirable notes, in the same way as it does on dark roasts. So I buck the trend, but I have to go by taste. I do find that pressure and duration of extraction can make a big difference though. light roasts seem to like a longer extraction and a good preinfusion. I think people often vary temperature to try and make up for a suboptimal roast. I usually extract at 93.5C on my machine. If I change it I will sometimes go as high as 94.5 or as low as 92.5...not often though. Can people taste 0.5C difference, not usually. Roasters should also be creating roasts that extract well at the widest range of temperatures.

Is suboptimal roast code for underdeveloped, our just a general miss on what a bean could be if done well (but not well-done)? I've heard a few tails of profiled shots (CT1, etc...) pulling lighter roasts at much lower temperatures than the norm, but the recent Robot threads seem to reinforce the old "hotter is better" mentality for light roasts. I don't pay much attention to actual shot temperature, and go by flavor. I can't taste 0.5°C difference, but I pay attention too my routine and I can taste if a shot needs to be hotter, cooler, or if it was just right. Having a good intuition beaded on bean density and smell of the ground coffee helps me make preemptive decisions that get me closer quicker, but I haven't found a magic process to maximise results in the first try just yet.

3. Grind level again is really tricky. In the past machines were simplE and a certain grind level was required. Machines and grinders have moved on a bit and like everything else grind can vary with the rate we extract pressure, bloom phase, max pressure and extraction time....which of course doesn't have to sit within a rigid zone of 22-32 seconds or whatever. Much longer extractions can be done if desired.

Yeah. Whatever happened to over-extraction? Burnt (too hot)? Yeah. Astringent (maybe thats over-extraction)? Sure. But your absolutely correct about shot times being wide open. I grind to try and maximize the flavors I'm after in a cup, and make sure it's not a gusher or choked, but otherwise I think I'm usually looking to maximize the volume in the cup before blonding occurs. Sometimes this gets me a 27 second shot after 15 seconds of pre-brew. Sometimes it's a 54 second shot with a more traditional E61 style pressure ramp. One thing that astonished me is how sensitive shot time is to water debit. The difference between 4 and 8g/s with the same grind and dose can be bigger than the difference between ristretto and lungo with a fixed water debit machine. Its shocking, really.


It's hugely complex and I think the whole area needs to be revisited, if it is I think will also affect the way roasters roast. I'm hoping the next wave in coffee is going to really rethink how we produce shots, rather than the rather simplistic dark vs light roasting.

I very much agree. I might also add after reading more about your work in the field that you, Sir, are a Specialty-coffee-preparation-method Bad Ass. Very cool to see how much influence you've had over the years and I'm mighty glad to have your participation in these conversations.

Cheers!

- Jake