The theory does seem to work when I switch to the 22. It's also not too bad on the single, in that the same grind as the 18 seems to work, although the above mathematics doesn't seem to apply to measuring the dose.
The theory does seem to work when I switch to the 22. It's also not too bad on the single, in that the same grind as the 18 seems to work, although the above mathematics doesn't seem to apply to measuring the dose.
A quick technical point: depending upon which international standard you pick, a normale is a coffee fluid weight / raw bean weight ratio of between 3 and 4 (i.e. a 22g would give from 66g to 88g of "in the cup fluid", crema essentially weighing very little). Considering water mils and grams are interchangeable, coffee would be close as well (similar density). At 2:1 you are well into ristretto territory. Nothing wrong with that, however it is not really a normale...
That leads me to the next point, the standards seem to depend upon which country you are in, and keep changing anyway! Over the years the amount of a single has crept up from a range of "5g to 8g" (Illy: Espresso Coffee, the science of quality, Italy 1995) to "8g to 10g" in some US's "standard articles" I have read (did not keep the reference, as it was poor: but coffee geeks US seem to have accepted it). Similarly, the final yield ratios (mils in cup) have also dropped over the same period. BTW, a standard pod machine is generally in the 5 to 8g range and the new "giant single pod" is 10g. Same trend.
Anyway, after getting somewhere near the ball park (i.e. my "starting point post"), always tread your own path.
FWIW, to me it just means you are tinkering and that is all to the good!
Enjoy your cuppa(s).
I have first hand "reasonably extended" experience with around 10 sets of VSTs plus a quick play with a much larger number of other sets. As stated,maintaining the same dosage ratio has meant very little tinkering required in going between any of the sizes. I often set up a system with a 7g single (at 7.2g) and usually check all sizes at the site before I leave. I pay particular attention to the 15 (15.4g) / 18 (18.5g) & 22 (22.6g) as they are more common than the 20 (20.6g). On every system (mainly La Marzocco's & La Cimbali's, or my own 2 group La Pavoni & SB 6910 & 7000) they are extremely close in "shot timing before blonding" - usually less than a second. Of course, using accurate scales is essential to set up gear - mine are Bonavita's, which are designed for coffee and even come with their own drip tray - however any accurate "0.1g" scales will do the job.
Even after many years making espresso's, my own dosing by eye is far less accurate than the small VST basket size differences - about 4 seconds variation before blonding is closer to my norm.
So FWIW, I reckon that IF you get such a different result in your 15 AND you are weighing your doses to that kind of accuracy WITHOUT altering the grind and tamping pattern AND pulling the shots during a brief period on the same day using the same machine THEN your 15g VST must be faulty. Sorry 'bout the touch of computer coding coming out, but it is faster than prettying up the grammar.
Hope this helps
In light of TampIt's post, I'll add that I work in the '3rd Wave' industry so all my post applies to that style of coffee.
Re the VST 7, so you're dosing fairly close to 7gms? If you were doing a level and tamp rather than weighing then you end up putting a lot more than 7gms in. I haven't used the 7 all that much, partly because I don't drink singles all that often, but also because of uncertainties over dosing.
1) I might talk to the supplier: I would as long as you are using good scales to verify the difference!
2) dosing fairly close to 7gms?: Yes, I ran a mountain of tests a while back, and the 7g VST was optimised in terms of extraction at 7.2 on several different espresso machines. Extraction ratio has nothing to do with the quality of flavour, merely quantity, but if you want your beans to go further... As it happens, the flavour at 7.2 was equal top in flavour anyway: win win. It also had the most (& best tasting!) crema.
A quick sideways note: trad espresso extraction ratio: circa 15%. VST optimised: 21%+, i.e. 50% more flavour out of the same beans. It made me look at the single as a 10g+ in terms of impact, whilst the 15 was far too strong for my usual 220ml latte cup. My personal 22g VST is largely unused except for visitors who are heavy smokers.
FYI, 7.2g is 2 or 3mm below the "shelf" of the single basket. A "standard 5x.x mm tamper" is miles too big to fit. I ended up designing / getting built a prototype 316 stainless tamper just for the VST single. Beats using a Smartwater plastic bottle "balanced" by being about 1/3 full, which was the only thing I found that fitted properly.
The first photo shows the tapering we used (pre final polish so it could be photoed, as it became like a mirror), the second is complete with Pullman handle surrounded by its two "half brothers" (they are 100% Pullman 316 baristas, one for preliminary tamp, one for final tamp in any of the larger VST's I use). FWIW I find wood handles nicer to use, YMMV.
TamperPreSingle.jpgIMG_1663 2.5 Pullmans cropped.jpg
The problem with using such a small amount of coffee is that a minute variation in dosing, tamping or grinding will have a massive impact on the shot resistance & therefore timing. Initial setup with scales saves days of ginning around... Once it is dialled in, it is easy to pump them out as long as you watch the blonding point like a hawk: two seconds late is a definite sink shot, three seconds might as well be .... (insert "really poor instant coffee of your choice's worst floor sweepings" here). It is a bit like using smaller jugs to froth milk: everything happens a lot faster!
A little more info:
VSTs can be optimised over a very wide range of doses as long as you match the grinding texture: i.e. up the dose / grind coarser or vice versa. As 7.2g is optimised at about 35% finer than traditional espresso grinds, a good "fine grind grinder" is needed or too many "unwanted fines" will make the shot go bitter too early. A number of large commercial grinders cannot deliver such a fine grind (nor are they designed to), hence some of the CS flames. My old calibrated SB 480 can (using the same workshop as the single tamper), as can my Mahlkonig Varios "out of the box".
VSTs are also very responsive (finicky?) to tamping methods, which is why I added that bit in my earlier post. Inconsistent tamping will wreak havoc to the point I recommended one particularly "coordination challenged" person not to tamp at all, just weigh & then pull the shot until they got their act together. Not as bad a "punishment" as it sounds, several world barista contestants have not tamped over the years.
Hope this enlightens rather than confuses.
It does a little of both.
Compared to a standard basket, the main implications are**:-
1) The flow rate is massively higher and more consistent.
2) The even hole size means that you can grind it finer without getting mud*** or bitterness (grinder permitting: as stated earlier, that is far from a given). Time for a brief dishonourable mention of the traditional belief that "a variety of particle sizes is a good thing". It isn't. I am expecting a few flames on this point, but the rationale is too long for this post. Short version: a) a more consistent particle size extracts more evenly and b) less unwanted fines means the shot can actually be run a bit longer before bitterness sets in. A good modern grinder can give a very uniform particle size, which a VST can take advantage of far more effectively than a standard basket.
3) If you can grind it finer (reduce the particle size), then flavour must extract more rapidly (i.e you get more flavour out of the beans in the same timeframe). The old surface area to volume ratio in action.
4) The time taken to blond is relatively unchanged**** within the "VST to traditional espresso range" of grinding textures at circa 25 seconds when optimised for flavour quality. Presumably that is because the bitter components start to dissolve "en masse" at around the 30 second mark regardless of grind size (unwanted "micro fines" disregarded).
5) Combining the above means that if you run a matched pair of optimised shots (i.e. finer grind for the VST and standard espresso grind for the standard basket, same dosage weight) to the blonding point (i.e. a "normale") then the VST extraction rate is about 50% higher than a standard basket. That part is clearly & easily measurable. Needless to say, the extra flavour whack is obvious. Another way of looking at that is you can use a VST basket about 1/3 smaller and use about 1/3 less beans and still get the same flavour quantity.
6) Alternatively, you can avoid bitterness (whether via grinder issues or simply personal taste) by running the VST shot shorter (i.e. a ristretto) which will have about the same flavour quantity as the normale in the same dosage "standard basket": but with a lot more "low notes" (richness) at the expense of some of the subtle "high notes" (whatever the beans & roast combo can deliver into the cup). Of course, adding the wide variety of bean varietals and roasting attributes can then give you a much wider range of desirable "in the cup characteristics". An interesting side effect is that you can also use a much lighter roast, run it shorter and still get a well balanced cuppa out of a VST (no "wheatgrass in sight"). I suspect that is one reason they prefer to use VSTs in barista championships.
In a real cafe, tinkering with roasting profiles and machine setup means that it is fairly straightforward to get a vastly superior "in the cup flavour" whilst using about 20% less beans (i.e. a cafe can effectively "split the 1/3 extraction difference" between improved flavour and more efficient use of the coffee bean. The finance maths actually work strongly in the VSTs favour.
Hope this is clearer now.
dialled in*: Please note the earlier comment about dosing more / grinding coarser: there is a large "workable range" with a VST. One CS post somewhere managed to put 16g in a single and still balanced the shot and I believe them. It is certainly easy enough to do. FWIW, the 5 cent test has a lot to answer for when using some newer designs in gear.
**explicit assumption: similar dosing percentage, which is unlikely other than during testing! However, you have to start somewhere... Another valid way of testing it is to match whatever dosage weight is in the standard basket (usually overdosed by a wide margin, 22g in a standard 15g is common) and use the appropriately sized VST (a 22g in that case) to get the dosage within the VST basket's +/- 1g. Either testing method gives equally clear results.
mud***: most standard baskets have wide range of hole sizes (look at one through a magnifying glass). If they have a few larger holes (all my old baskets do) it means that a finer grind can let coffee particles straight through. Similar to the mud at the bottom of a Turkish Coffee, hence the nickname / jargon. It also goes really bitter because it sits in the cup stewing.
relatively unchanged****: Actually, in my experience the VST can run noticeably longer shots than standard baskets, but only with a really good grinder. Whole 'nother can of worms.
Wow! That's quite a reply. Footnotes and all. Thanks.
For the record, I'm using an M4D grinder which should be up to the task, and an E61 HX machine. I've also developed a reasonably efficient approach to ensuring even distribution for the VST baskets, and use a bottomless often to check for evenness.
I am generally aware of the idea behind VST. Precise cut holes, more of them over a wider area of the base, grind finer as a consequence, etc. it's why I bought a set of baskets when I bought VST, because switching back and forwards between them and OEM would be a pain. Especially on a micrometric, even though the change in adjustment is not huge.
While I've been weighing the beans before and after grinding (i.e. I'm single dosing), I haven't paid that much attention to the brew ratio. Before I comment any further on my issues with the VST15 I should start doing so, since it may be relevant.
In my time on the forum I've read the differing views about dosing by weight vs dosing by volume (5c test). [Wait for TOK to arrive and push volume dosing ... ] Generally I've tried to combine the two. On my machine I get about the same answer, although after I upgraded to an IMS laser cut shower screen, I found that I had a little more headroom and increased the VST18 dose from 18.5 to 19gms. However there's a very large discrepancy between the two approaches on the VST7. I guess I can't compare them in practice without a suitable tamp for the 7.2 gm dosing. I might comment more once I do.
p.s. Are you able to open the can of worms and explain "relatively unchanged****: Actually, in my experience the VST can run noticeably longer shots than standard baskets, but only with a really good grinder. Whole 'nother can of worms", or point me to a post where this is discussed please?
Glad it was appreciated. I wrote a more technically detailed reply because I felt you deserved a more complete answer (plus your timing was good: I am "long on to do's" & short on hours too often lately).
I only became involved in extraction ratios because I saw a David Walsh talk (similar to Tamper Tantrum Live, Presentation Number Six David Walsh : Tamper Tantrum) and felt compelled to confirm his stated concepts. IMO he is 100% correct. Before I arranged the test gear, Max Kaminsky and then Matt Perger were exploring similar concepts. Luckily a friend has a medical stainless steel engineering workshop with the kind of test & manufacturing gear most CSrs would die for (me included). As an aside, he made my prototype single tamper out of a bit of scrap 316 (the lowest grade of stainless he uses) in about 10 minutes, measurements & "Pullman compatible thread for handle" included.
IMS laser cut shower screen: I am not surprised it makes a difference. AFAIAC, anything in the "water tank (plumbing) to cup" path could (and probably does) make a difference.
Back to the workshop: I conscripted a few coffee friends, half a dozen or so grinders: my old Major, Bo-ema RR45, 2 * SB 480s (modded: semi stepless & calibrated by the Bo-ema) and a few other "well regarded commercial grinders" which should remain nameless. I also obtained a few different technology espresso machines (my two SB6910's & 2 group La Pav and friend's Linea and the Silvia I once owned amongst others) and spent a couple of days trying to make sense of VSTs and grinding issues.
Day 1) We started with the larger VSTs & matching doses as described earlier with standard aftermarket baskets (both methods), using the various grinders. The VSTs are capable of massively higher extraction ratios as long as the grinder is good enough to grind a lot finer than the usual espresso settings. Four of the grinders weren't up to it (poor particle spread). Initially the ratios climbed easily from the 20% mark to just over 25% when we tinkered. Mid 22% extractions tasted better than the higher ones. The best I managed out of a good aftermarket basket was 17%, however it was undrinkable. 15% shots were much better to drink, 16% were barely OK. Although the cheaper machines made me work a lot harder to get the best results, the machines made surprisingly little difference to either the extraction or flavour compared to the different grinders. I had a strong feeling that the VSTs were taking longer to blond, however it was "comparing apples to oranges", so to speak.
Tentative conclusion: the VST had basically the same overall effect on flavour (much cleaner quality & stronger quantity of flavour, however the actual shifts were similar), just at a much higher (circa 50% more) extraction level. Later testing showed that was mostly correct.
First wrong tentative conclusion at end of day one: there is a maximum extraction that should not be exceeded because the flavour quality drops off rapidly.
Day 2) We started to get serious about particle spreads. Here is the real start of your "whole 'nother can of worms" request.
The traditional theory is that you need a mixture of textures to give the puck resistance.
Commonly quoted example: Get a bucket with a lot of small holes in the bottom. Fill the bucket with marbles (i.e. uniform spread) and the water pours straight through with almost no resistance. Empty it and do the same thing with sand: no flow work talking about. Then try it with a mixture of marbles & some sand and the water pours through slowly and evenly. Traditional Conclusion: need a mixture of particle sizes to get a good, controllable flow.
David Walsh has a totally different take. Fines dissolve more quickly and introduce early bitterness (bad idea). Larger particles (he calls them bricks or logs if I remember correctly) take a lot longer to dissolve so they have little effect on the flavour in the cup unless you run the shot so long that the fines have made it undrinkable: far too bitter. If you remove both the unwanted fines and bricks via a sieve, it is then possible to optimise the shot around a single particle size AND the result in the cup should more detailed (i.e. be better if it is a good coffee).
So we started by holding the dosage to the optimised values from day one and altered the grind to obtain the desired pour times and then tinkered again "pre and post sieving".
Fairly firm conclusion (major can of worms start at the second one):
1) The more even the spread the better the shot. When we sieved a few grinds (fast and easy in that workshop) the poorer performing grinders (remember this is grinding outside their spec) improved dramatically. The other grinders showed much less changes. All very simple...
2) The more even the spread, the longer all baskets took to blond. However, the VSTs could take three or (rarely) four times longer than expected at certain roasts & grinders, while the standard baskets rarely even managed to double the time. To some extent, grinding coarser again shortened it (as you would expect), however the extraction & flavour both went out the window. Any ideas? Considering the VST flavour advantage, that is only a mild curiosity to me at this time.
3) Tentative conclusion from day one got smashed. The "best of the best" (& some of the "near worst") shots were the highest extractions. However it was a tightrope: rarely, but a few times, they were bitter long before they blonded! Considering the three roasts were exceptionally uniform (by design), that one could be this human's error somewhere in shot prep (no, it is not a temp / pressure thing in the machines).
4) The 23% extractions were consistently good+, however some of them were longer than expected pours for no apparent reason. Blame the "mano" again??? Tiredness & deadline pressure may have played a role (had to return everything borrowed pronto + return the workshop to dealing with stainless).
I feel fairly confident that Walsh is correct. I would add an alternative to the bucket example: find smaller particles than marbles (round gravel, beads, whatever...) and somewhere is a point where you get a very even controllable pour with uniform particle sizes. In the case of coffee, I am convinced it is better than the wide variations in spread that has been "designed in traditionally" for years.
Now: why does a VST take a lot longer to blond? Higher flow rate: no, should be quicker. Finer grind: no, should be quicker (smaller particles dissolve faster). More even particle spread / the VST reveals the "point of no return more clearly by stretching the time: not likely AFAIAC! "more consistent flow": ????? clutching at straws here...
I look forward to your thoughts on this lot.
All the best for Xmas.
Tampit, my friend. You're not, by any chance, a distant relative of Marcel Proust? Got to admire the effort.
The term hypergraphic springs to mind.
Another Wow! Another mini-novel. I hesitate to say too much in reply, lest we get a trilogy.
I do understand the motivation to write mini-novels like this, as I've just written a couple of them myself in the last week or two. In a completely unrelated field. But when you've struggled with a technique over a long period of time. and developed a view different to the prevailing orthodoxy, and then a new user comes along and asks an innocent question, then .... they get more than they bargained on. Because you have the incentive to write it all down and document it. So I can relate to this.
What are my thoughts? I'm in over my head, that's what I think. I think the even particle size argument makes sense, and especially for VST with its precise and even holes. i haven't studied fluid dynamics, so I'm agnostic about particle size and flow rate, although common sense suggests that VST will behave differently to a basket with uneven hole size. As a relatively new CSer, the extraction ratio stuff is a bit over my head. And as for wet grinding ....
For a tradition espresso roast I tend to find that weight and volume dosing are fairly close in doubles and triples. Where then tend to diverge a little is for lighter roasts where I prefer to grind a fair bit finer.
I have been having a private discussion with another CSer about the difficulty of picking the blonding point with VST. The view expressed to me was that it tends to happen more gradually with VST that other baskets, which I am inclined to agree with, but that the taste changes more suddenly that the gradual blonding would suggest, so you have to be alert and don't let the flow go on too long. I'm still testing that. Your views?
How refreshing..... discussion rather than discourse! ;-)
Sorry I missed this one earlier. Given your wonderful contributions to this site, I would feel privileged to sample your coffee next time I am up that way. Especially as I have been a closet "cold steeper" for (far too many) years.
One of my peeves is the number of ignorant CS posts about 3rd wave. Clearly most of them are unaware that it is merely "pushing the coffee experience envelope" in many different directions, some of which are sorely needed whilst others "not so much". It reminds me of the "old Italian Master" who taught me about Carmencitas ("stovetop espresso pots"): to the day he dropped he always called crema "scum" and regarded the new wave of espresso makers from Gaggia (1950's) as "the spawn of the devil".
My take: viva la difference! I am willing to appreciate coffee is all its forms as long as it does not include burnt roasts or scalded milk.
All the best with your craft
No danger of a trilogy mate. Partly I felt that this thread had gone off track, so a little conceptual rigour would not go amiss.
Wet grinding: I defer to Walsh on that one, my only attempts were "interesting" rather than worthwhile.
1) Yes, VSTs are harder to pinpoint blonding. Overall, VSTs gave me a lot of grief early on: mainly because I had a lot of "unlearning" to do. Most newbies make me look like an idiot given my painful VST journey. A bit of correct training and most "new coffee people" get a VST to sing very quickly.
2) How do I spot blonding on a new site: a good light from the side and a little to the rear helps a lot. I often resort to the torch on my mobile given most cafe's "mood lighting". At least that is preferable to the "interrogation lights" at one ES cafe I encountered. Customers rule, OK.
3) Another observation: perhaps it is experience / practice, however I am usually about 5 seconds ahead of most baristas in cutting the shot when I am trying to hit the blonding point exactly. Considering I find ristrettos a bit bland, I must be "close to middle" (i.e. a balanced shot). FYI, I use two Mahlkonig Vario gen2's at home these days: they have a very consistent grind and timer so dosing is more accurate than most gear. As a side effect, that makes picking the blonding point a lot easier as it reduces the potential window to my "personal 4 seconds variance" rather than dealing with an extra pile of machine variables.
Enjoy your journey
Because of their all-over hole pattern, VSTs use nearly the whole puck, out to the edges. Most other filters, because they lack holes near the perimeter, leave the grounds around the edge underextracted.
So when you compare the results using a fixed dose with VSTs vs the same dose with most competing filters, the VSTs perform like they're working on a larger dose -- about 15% larger, to put an average number on it (that's approximately what I've measured). Consequently, when you compare VST-made vs "other" espresso shots, using the same dose and running equal flow rates (ml/sec), the shot working with 15% more grounds is going to blonde about 15% later.
Is that what you're talking about or am I missing the point?
I ask because I have read studies of flow in packed beds which suggested fluid velocity (and thus extraction rate) is highest near to the bed walls; although fluids being fluids, this effect may not scale to the conditions in a coffee puck.
I understand that this observation doesn't directly prove the the HQ shots are underextracted around the perimeter, but after looking at the filters and pondering the differences, I have no other explanation. This can be more directly tested, but doing so is a tedious procedure.
I'm open to suggestion if you have a different, credible explanation.
I also understand that the HQ is described as a 14g filter but from what I've read, most people use it with an ~18g dose. It certainly has the capacity for that.
I wish I knew what conceptual issue I am missing, so there is no way any poster could "miss the point". That is why I decided to throw it out there. Any thoughts are welcome, at least by me.
Yes, I agree the VSTs do act as though they are using a larger dose than standard baskets - even when they aren't. FWIW, if you fully optimise grinding and tamping to suit, the difference seems to climb exponentially. Maybe I am missing something elementary, however I cannot seem to relate that to the extra blonding time in any significant way. Given a truckload of measurements from all over the world confirming standard baskets top out at about 15% extraction and VST's go well well over 22% (23 to 25% is a commonly reported measurement), the potential difference in extraction is more like a 50% jump (as stated in my post).
I ran out of time during testing. Obviously, I have a real professional life which greatly interferes with my coffee passion.
I also wanted to test whether the height of the puck affected blonding (whether inversely, directly or neither) - considering a VST22 blonds at almost the same time and relative grind / dose / tamp settings as a VST15, which is the same diameter & a lot lower in height, I doubt it. Also there are numerous smaller basket diameters out there (i.e. Electra manual lever at 49mm) which have a correspondingly deeper level of coffee, and I have never suspected that makes a significant difference either.
The fluid dynamic studies about "extra side flows" I have accessed are 90% irrelevant: they all use straight sides (think rectangular channel) or constant radius curves (then the increased frictional losses due to less depth means the edges flow more slowly: seen for real in any number of creekbeds). The studies I have are not carried out at 9 bar pressure either. Just another red herring AFAIAC.
I imagine quite a few of the VST research dollars went into sorting out the complex taper of the sides to even out the flow. Simple observation: the tapered sides of a VST vary slightly as the size changes. That plus the "holes to edge pattern", the size of the holes (22 is bigger than 20 and so on) and the hole shape are obviously meant to attain an even flow across the whole basket. When I tried multiple pressure sensors on a VST, it remains the only basket I have measured that displays no differences at the basket's output no matter where a sensor is placed. Perhaps smaller sensor surface area would change that?
Still doesn't get to grips with the blonding time, but there you go!
Enjoy your EK43 (lucky ***)
man, i was contemplating some of these baskets, but reading this thread and a few others online, i am going to put it into the too hard basket, and stick with the stock ones that came with my r58
Say you pull two shots using an 18g dose. One's with a VST filter and the other with some other filter. You tune the grind, etc to get the flow rates out of the two filters closely matched.
The VST acts like it's working on an 18g dose while the other filter, because of its design, performs like it's working on a smaller dose.
But your flowrates are matched, so you're running water through both filters at the same rate. The VST shot will go longer before it runs out of solute (before it blonds) because it's working on the "larger" dose.
Last edited by ASchecter; 12th December 2014 at 01:40 AM. Reason: to clarify the explanation
Agreed, not hard to use at all.
I find that because the VST require a finer grind , I get better results using a light tamp , this is just going of visual of the extraction with the naked portafilter , I would recommend trying a lighter tamp and see how it works for you
I have ordered on behalf of my two sons their espresso equipment ,a task I thorouhly enjoyed . Amongst the shiny things I orded a set of VST baskets with naked portafiller .Both sons plus their sons use these baskets as though they are part of normal coffee extraction. None of the five home barristers have ever indicated they have trouble with the VST baskets because these are all they know.
Just to be clear, since this is buried in some long posts above. My understanding is that given the same roast, grind, dose (proportionately) and tamp, you should get the same pour time to blonding. That's one of the advantages of VST, and that was Tampit's view and experience, which you can read about above. I am more than happy with the 18gm & 22gm, since they're fairly close.
My problem is with the 15gm, which has a much faster pour time and so I need to grind a fair bit finer. Is this normal? Tampit said no. The supplier said yes. Hence why I am a little confused and not entirely happy. I am tempted to take up Tampit's suggestion and buy a second 15 to see it behaves any differently, but will probably choose another supplier.
Interestingly my 22 and 20 g VSTs require similar grind fineness, but the 15 g requires a significantly finer grind.
I use the 15g most of the time, because it's just me. It delivers well and a nice strong coffee.
I found I had to adjust things for the 22g that I use when I have a guest who isn't a decaf type. (I have a separate grinder for decaf and use the EM7000 basket for it - the wife is caffeine-sensitive) What I found was the 22g would choke at the same grind/tamp - and I was weighing the dose, albeit only to 1gm accuracy - eventually I sorted a different tamp technique which seems to have resolved it - every so often I have a blast by making myself a coffee from the 22g basket just to make sure I keep my hand in.
I got some good results out of my 18g vst today. The extraction was thicker more caramel like than usual which I'm sure had to do with the beans roasted 10 days ago. The problem was it was only coming out of one side of the double spot em7000 portafiller. As it poured I looked closely and it looked like it needed to be a little faster or a tad less thick to so the pour would push to the second spout. Would this have been due to an uneven tamp?
It can be the result of an uneven tamp. The VST baskets don't seem to like that very much. I also use the 18g basket.
Since I am quite confident in the evenness & consistency of my tamps, I put all channeling down to clumping. I confirmed that by adopting WDT into my routine before tamping & now I consistently get some of the best & most even extractions I have ever seen. I had refused to adopt this as I always considered it extra effort and unnecessary. I now know that's not true with the 'clumpmaster' Mazzer mini e.
With the weighing - I found that when I weigh 18-19grams of grounded coffee direct to the basket, I get a certain weight but after I Tamp it, I weigh it again and it weighs lighter :? Either my scales are defective - not surprising being one of those $10 homemaker ones from Target but I wouldve thought tamped or untamped the weight should be the same. If I'm supposed to be weighing in 18-19 grams tamped, then I am underdosing the basket.
I guess what I want to know is - do you weigh in 18-19 grams of ground coffee into the basket tamped OR untamped?
Tamped or untamped the mass of the coffee remains the same. If you get different measurements between the two then either there's a problem with your methodology (Most likely the removal of coffee from the basket during the tamping process.) or your scales are whacked.
Java "Yay for Science" phile
Toys! I must have new toys!!!
Make sure you zero the scales before each measurement, and calculate the mass based on the difference between the two measurement. If you zero with an empty portafilter on it, and try to weigh the difference, it can result in error.
Warning - the post below does and will not mention a name or any name of filter basket it's apparent performance or in any way refer to
The champion poster of aforementioned unsaid brand of filter. HUH..... those who know will know what this means! 🍍
Once I set up a new basket - trial dose / measure relationship to the heat sink & shower head/ head height gap, then measure the desired dosage for a correct (?)dose setup, I then throw the scales back where they belong.
To me its all about the final reading of the puck and how it contacts the shower screen / shot timing / shot flo & characteristics. Etc etc
I believe you can underdose or upnto and including a proper dose. but overdosing is basically useless AFiC as it literally says the puck will be disturbed / fractured by the heat sink / shower screen.
Dosage to me has to be a relationship between the components as measured against each individual brand / model of espresso machine.full stop
Finally what means most to me is this combo - beans freshness / roast / other attributes, tamp as varied on any shot ( if you decide to vary tamp pressure) and finally shot characteristic / timer. Of course ultimately this leads to the final arbiter - the taste test!
If you time your shot - it will literally tell you the story. .
Ultimately once at this process the biggest variation is bean variety, roast style, freshness.
I've rigged it so the scales sit under the grinder so as I grind into the portafiller I can read the weight as it rises to 18g.
That could be it! I'm only zeroing the scales at the start. I'll put an empty portafiller on the scales, zero it and then grind into the portafiller. I get to about 15 grams then I have to remove the portafiller from the scales, distribute and lightly tamp to allow room for more grind. Then I'll throw it back on the scale and continue to grind the remaining amount without zeroing it. That's when the scales get all confused. If I zero it before regrinding then I know I only need 3-4 grams.
Will try this
Sounds like it might be your problem
My way is to:
1) zero the scale and weigh the PF empty
2) calculate what the total weight will be
3) dose into the pf
4) re-zero the scale
5) check the total weight
6) if the total weight is less than my calculated value, return to step 3.