Extract Mojo and VST baskets, a perspective from a professional, daily user - Page 2

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#11: Post by RapidCoffee »

Hi Scott, thanks for weighing in. I hope you will not mind a different perspective.
bigabeano wrote:I believe the ways many H-B'ers have approached Extract Mojo (EM) and VST baskets has caused them to misuse or misjudge these products. Many have expressed blind faith in the testing done by others, and have rejected these products out of hand without any personal experience.
I don't find this statement to be true, either in general or for the recent filter basket study. Speaking for myself: I am an equal-opportunity skeptic. There are no sacred cows, and anything is open to questioning and further scrutiny.
bigabeano wrote:In fact, my business partner Anthony (a fantastic barista and an equally avid user of Extract Mojo) and I often play a guessing game, usually successfully, in which we taste a brew, guess the extraction %, and then check our guesses against a refractometer. After a few hundred such tries, it has become relatively easy to guess the answer to within +/- 0.2% extraction.
This is an astonishing claim, and one that needs to be backed up with data. Pardon my skepticism, but even if true in a commercial setting with highly trained coffee professionals, this seems very unlikely in the totally different home barista environment.
bigabeano wrote:As for VST baskets, (see: How filter baskets affect espresso taste and barista technique), the scientific approach Mr. Schulman took in comparing baskets had two tragic flaws:
Neither flaws nor tragic. Jim chose to measure flow rate vs. dose for a given set of baskets, and reported those results. If you would undertake a similar study, and supplement our results with refractometer data, that would be great. If asked nicely, I would be glad to do more basket hole analyses. :D

Our study does not address consistency between baskets, or basket sturdiness, which are relatively unimportant issues in the home. The results provide support for VST claims of less variation in filter basket hole size, although the basket sample size is clearly too small for "proof". Claims of greater consistency in extraction... well, that depends on how you interpret consistency. We did not test a dozen 18g VST baskets for consistency; instead, we studied over a dozen different baskets. Small changes in dose had a greater effect on VST basket flow rates than other baskets in the study. This makes it harder to achieve consistent pours from the basket, not easier.
bigabeano wrote:One caveat: You will get better results and fewer micro-channels if you use a 58.4mm tamper in conjunction with VST baskets; good results can be achieved with a 58mm tamper, but better results will be achieved with a 58.4mm tamper.
There is huge diversity in tamping, with handstand tamp vs. no-tamp proponents, tappers and polishers, NSEW and nutation, flat vs. curved bases, etc. etc. Both you and AndyS have stated that a difference of 0.2mm in tamper radius is significant (although Andy's claim is confounded by flat vs. curved bases). This is another extraordinary claim, and one that should be supported by strong evidence, not just anecdotal remarks. Furthermore, this statement, if true, provides additional evidence for the "fussiness" of VST baskets.

Disclaimer: Scott was kind enough to send me review copies of his excellent books on Espresso and Coffee. I am a big fan, despite my disagreement with his posts on this thread.

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#12: Post by malachi »

If you have a very high quality grinder and you are using a coffee that responds well to the particular parameters the VST baskets are designed for and you like the style of espresso produced using these baskets then you should get the baskets.

To further clarify....

Grinder = modified Anfim Super Caimano, K-10, Robur or the like (NOT a super jolly et al)
Coffee = something that extracts optimally using the design criteria of the VST baskets (ideal extraction yield in the 19%-21% range, insolubles equal or less than 5% total brew solids)
Style = clean, transparent (definition of flavours prioritized over body and mouthfeel)

Personally, given the range of coffees I work with I simply cannot use only the VST baskets. While my grinder is sufficient for the task -- there are just too many coffees that I work with that are non-optimal at those parameters (or where the ideal extraction prioritizes viscosity or body).

They're a useful addition to the barista arsenal IMHO.
But you need to understand what they do and don't do and how they do it.

Oh... as an aside, they definitely work best on SO espresso or 2 or 3 bean blends where the beans are very similar and they work worst with complicated blends especially if there are naturals in the blend.
"Taste is the only morality." -- John Ruskin

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#13: Post by Anvan »

Scott, thank you for taking the time to carefully compose your lead-off article. It explains some phenomena I've experienced in practice and fills in some background perspective that will prove very helpful - it certainly has for me. And on a personal level, I think Jim is universally recognized as an honest and indefatigable taster and writer (and one who has also helped my understanding immensely over the years) and it's a pleasure to read when that respect is played out over fair differences of perspective, experience and opinion.

Regarding BDL's question of practical application of this thread, I would highlight one of your statements:
VST specifically recommends using a particular dose with each of their baskets. (for example, a 22-g dose with the 22-g basket.)
+1 to this: I did not realize it at the time, but looking over my coffee logs and tasting notes as of with my conversion to the VSTs, I've seen a steady change in on my dosing that zeros in on VST's recommended weights. For example, where I once used 19.5 grams for a particular coffee in the 18g basket, I see that I've reduced that number steadily over time, first to 19, then 18.5 and finally 18. As I did so, the resulting shots (rated by taste) improved, although the changes of the "technical" aspects (visual quality of the pour) weren't as obvious. So subjectively, I'm pretty sure that the taste improvements were subconsciously driving my changes.

Checking my sheets, I can say this was true for both the VST 18-gram and 15-gram baskets. I'm not really sure about the 22-gram version: I don't use these as regularly and so my data is insufficient (and regardless, to be honest, an updosed 22-gram basket seems not unlike one of those 84-ounce steaks which the restaurant advertises will be served free if you can manage to choke it all down).

I can also say that has applied almost universally across many coffees, including Red Line, Redbird, Water Avenue El Toro, Dolce, Ritual, Hairbender, Black Cat Classic and Coava's amazing Guatemala SO. The exceptions have been with decaf versions, where my favorite results still seem to ask for an extra 1/2 - 1 gram which - I'm guessing anyway - may be due to the different way in which decaffeinated grounds behave in the extraction process.

So as a practical matter (and folding in Jim's well-known grind->dose advice) I would recommend to those starting off with the VSTs to AT FIRST use the 15-18-22 dosages - for which the basket designs were expressly optimized - and adjust your grind to provide the best result at those dosages. THEN, having established the benchmark, tweak the dose up or down to your liking.

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#14: Post by boar_d_laze »

John -- Yes! Your post hit many of the nails, and always on their heads. But -- before this thread totally drifts into how best to use the baskets -- there's something larger at issue. The term "scientific method" has come up in this thread, and it's particularly relevant in that the most important part of method is clearly identifying your own damn questions. So, while I agree with you entirely, the biggest problem I have with the OP is determining its point.

Chris -- You're restricting the utility of the VST/Strada baskets by way too much. The doubles were (and are) a huge improvement for my setup compared to any and every other basket I've used. While my pull is about as far from your paradigm as possible: "Normale," ~17.5g dose, ~35g extaction. My opinion is not unique in that other people have commented on the improvement without an inkling as to its source.

My guess is that the two most important factors vis a vis my own coffee are: (1) The geometry of the new baskets allows an appropriate amount of headroom for the desired shot size and type ; and, (2) The hole distribution which extends farther towards the edges and is more even throughout, creates less (or better) turbulence -- particularly around the edges.

Jim did a good job of establishing some areas going beyond case by case.

Drop a nickel in the pot Joe. Takin' it slow. Waiter, waiter, percolator

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#15: Post by Bob_McBob »

I've always wondered how many Mojo users actually follow a rigorous testing protocol when doing samples with the refractometer. I've seen a number of videos with extremely haphazard testing procedures like grabbing a spoonful of hot coffee from the cup, sloshing it in the well, and immediately testing. Having used a coffee refractometer fairly extensively, I know I have to be pretty careful about the way I test to get consistent and meaningful readings that don't change over time.

I'm also curious about how you are supposed to calculate water loss ratio, which is a fairly important part of the formula used to generate the results. I've never seen much written about it online, and the feature was actually broken in the MojoToGo app for several months. If you go by the final beverage weight for a single cup brew, the variance in amount retained in the brewing device can significantly impact the results. For instance, the CCD retains a decent amount of liquid in the valve mechanism if you don't shake it out, and the Espro Press is basically impossible to get a reading on because of the amount of liquid retained under the filter. There is also a massive difference in retained liquid between a Turkish grind and a very coarse press pot grind. I basically never see anyone mention WLR or adjusting for it when discussing the EM.

On the whole I find it pretty annoying that the only forum with serious discussion of the EM is off-limits to me.

bigabeano (original poster)

#16: Post by bigabeano (original poster) »

I apologize for making these replies short. I ration my typing due to a wrist injury, and I'm a bit overwhelmed by the number of replies. Plus, I don't want to spend all day online (I know, strange)

Jim wrote:

On the taste side, I made:
  • a shot with 11 grams of coffee and 16.5 grams of water using an LM single on the same machine in the same time and with the same pressure and grind setting as a 17 gram shot getting on the VST 18 with 25.5 grams of water
  • they both tasted the same cold
Jim: i don't know why you thought they tasted the same. They could have had the same extraction, but you didn't measure it. Plus, I don't see why two shots tasting the same when cold is so important, given that people generally drink hot espresso. I imagine your shots did not taste the same hot, which is more relevant.

Jim, as for the 58.4mm tamper, my experience says that channels occur much less frequently with a tamper of a certain fit. I have no idea how I would present evidence for that. Please suggest. I will say extraction levels are slightly higher for a given brewing ratio/grind, etc when a tamper fits better. That probably implies preferential flow paths (i.e. microchannels) occur more frequently when the gap between the tamper and basket is too large. Sorry this doesn't meet your personal version of scientific rigor. Anyone else reading is welcome to simply find this out for themselves by pulling a few hundred shots each with several different tamper sizes and one well-made basket.

Dick: Regarding altering variables and thereby changing flavor a lot while not changing extraction much: this is actually more difficult to do with espresso than one might think. For instance, let's say you pull a shot with a given basket at 19% extraction. If you change any variable enough to make a notable difference in flavor, you wil usually have changed the extraction level. You might think it's easy to maintain a 19% extraction while changing your dose by 1g and changing the grind to accommodate, but it's challenging. Most baskets, if they even can hit 19% (not all can achieve 19% without pulling a lungo), can only do it within a very small range of doses, unless you are willing to radically change your brewing ratio (i.e. run enough water through the grounds, and eventually you'll get to 19%). I hope that answers the question adequately.

Jim said:
"After I requested the additional information I needed to complete the error propagation analysis, Vince asked me to break off the review and return the unit. "

Jim, this is false, and you know it. I've was cc'd on some of the emails between you and Vince. My understanding was that the Extract Mojo system was specifically donated to H-B and sent to Jim for his use. After 5-6 months and no use, Jim apologized for not getting around to testing it, and at Andy's suggestion, sent it to Dan.

BDL: To me, the relevant benefits of VST baskets are:
-Each one is nearly identical. This is important when using three baskets in one machine, and important when using the same tamper all the time and buying new baskets. Most other basket brands are not made nearly as consistently (data will eventually be made public about that, but it can't be, yet. sorry) Jim and John would have seen these inconsistencies had they increased their sample size of each brand. In fact, with some brands, they would have been appalled at the variation in hole area. Their data imply they got unusually lucky with the baskets they chose.
-The extra hole area makes it easy to get a 18.5-19.8% extraction, which covers (and then some) the preferred range for many of us (and the preferred range for EVERY one of my professional friends who takes frequent refractometer readings).
-For cafes wanting a combination of 19% extraction and adequate brew strength, and adequate shot mass to hold up well in various milk drinks, they're easily the best choice.

John: my claim regarding the gap between the tamper and the basket has nothing to do with VST baskets or "fussiness". I've found it to be true on every brand I've used in the past several years. And the testing was done with flat hand tampers. I don't pay much attention to the other tamping systems out there.

As for my claim about being able to guess extraction % by taste, regardless of your skepticism, it tells me that there IS a correlation between extraction % and flavor. Not to mention that after Jim posted "Some Aspects of Espresso Extraction" he posted a retraction of the entire paper (honorable, though does point to why all this should be taken with a grain of salt.) In that retraction, he let one finding stand:

"I also claimed that the taste of espresso systematically changed with the degree of solids extraction. This claim stands."

-Jim Schulman, coffeed.com, August 22, 2007


Chris: Your point about water retention in the grounds is excellent. It's something I think about often, and I have my own opinions on how to adjust for it. I'll say this: For different brewing methods, my extraction % preferences are very similar, but not always identical. I won't hijack this thread to talk about that, but if you PM me, I'll be happy to discuss it a bit with you.

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#17: Post by malachi »

boar_d_laze wrote: Chris -- You're restricting the utility of the VST/Strada baskets by way too much. The doubles were (and are) a huge improvement for my setup compared to any and every other basket I've used. While my pull is about as far from your paradigm as possible: "Normale," ~17.5g dose, ~35g extaction. My opinion is not unique in that other people have commented on the improvement without an inkling as to its source.
I suppose it's all personal taste but in talking with a large number of US and non-US coffee pros, I've found few who disagree with me.
"Taste is the only morality." -- John Ruskin

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#18: Post by boar_d_laze »

I suppose it's all personal taste but in talking with a large number of US and non-US coffee pros, I've found few who disagree with me.
Many of the large number using La Cimbali DT/1s? A lot of them drawing old-school 50/50 normales?

Drop a nickel in the pot Joe. Takin' it slow. Waiter, waiter, percolator

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#19: Post by Arpi »

malachi wrote:If you have a very high quality grinder and you are using a coffee that responds well to the particular parameters the VST baskets are designed for and you like the style of espresso produced using these baskets then you should get the baskets.
Couldn't that be said of any other particular basket?

To me, espresso shots, due to their complex nature, create a constant concocting source of believes and practices. I remember, long time ago, that to improve the flavor I starting making a dimple with the finger in the center of the puck. Some people swear for using the exact diameter to the size of the basket. Others swear not to tamp. And each find a way to improve their shots with tricks back up by self created observations and justifications of scientific intent. As if people only see what they want to see when making a claim and science is the tool to use. But even answering deeper questions, like for example what is better, is a source of disagreement among different people. And therefore, science is limited because there is no agreement on the pursuing goals, which change from people to people and from moment to moment. Sometimes they agree on what is better but it turns out it is a temporary trend. In espresso there are no solid foundations as to what is better or worse. There are only individual claims clustered sometimes in groups to later be dissolved by other claims or trends. Why do people try to rely on science when the object of study comes from the inside of each person mind, and it has to do with cultural phenomena, and has a subjective interpretative nature?


bigabeano (original poster)

#20: Post by bigabeano (original poster) »

This is my last post on this thread, as there are things going on behind the scenes that make me not want to contribute to the conversation anymore. However, I will pass along one paragraph, which I think a reasonable reader will find rather convincing about the precision and accuracy of the coffee refractometer:

The SCAA conducted formal tests in April of 2009 of the VST Coffee refractometer compared to the industry standard (AOAC) method of dehydration using an $18,000 microwave dehydration oven. The SCAA abandoned the old conductivity style TDS meter in favor of the VST Coffee Refractometer, which showed an accuracy and precision of +/- 0.02% as compared to their calibrated dehydration oven. They tested several units. Separately, the SCAE in Europe performed their own tests and analysis and adopted the VST Coffee refractometer in October of 2009 and made the announcement in Cafe Europa at HOST Milano. The Norwegian Coffee Association at the European Coffee Brewing Center in Oslo performed their own internal tests designed to compare the accuracy and precision of the VST Coffee & Espresso Refractometers against their traditional dehydration methods, in use there for some fifty+ years. They concluded the VST Coffee refractometer was as accurate as the dehydration methods, faster, and much less prone to user/laboratory error.