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Going insane with channeling, pls help!

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  • Yelta
    replied
    Originally posted by LaughingAtFate View Post
    I wonder how many folks who are being pedantic about fines, vst baskets, and tamp pressure are willing to work with a sieve and remove those pesky fines from their grinds...
    I have contemplated doing it, unlike Mal contemplation was as far as the project went, I would think to sieve fines regularly would rapidly escalate you into the world of geekdom.
    I suspect evenly distrubuted fines play their part by filling the voids between the regularly sized particles, in other words add to the extraction.

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  • Dimal
    replied
    Originally posted by LaughingAtFate View Post
    I wonder how many folks who are being pedantic about fines, vst baskets, and tamp pressure are willing to work with a sieve and remove those pesky fines from their grinds...
    Actually, I did do this a few years ago; first with my Rocky D/L, then a La San Marco (ex cafe) with original burrs and then with a new set.

    The intention wasn't to do this for every shot, but just to get a handle on the percentage of fines per shot and then comparing Old burrs with new. Can't see the point of doing it for every shot but the comparison between Old burrs and New was quite definitive and justified the purchase of new burrs originally based on the quality I was getting in the cup - Which is where it counts of course, the rest was just curiosity...

    Mal.

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  • LaughingAtFate
    replied
    I wonder how many folks who are being pedantic about fines, vst baskets, and tamp pressure are willing to work with a sieve and remove those pesky fines from their grinds...

    Leave a comment:


  • Yelta
    replied
    Originally posted by okitoki View Post
    had it since I bought my behmor, so I guessing around 6 months...
    So that rules out stale beans.

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  • okitoki
    replied
    Originally posted by Yelta View Post
    How old were the green beans?
    had it since I bought my behmor, so I guessing around 6 months...

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  • Yelta
    replied
    Originally posted by okitoki View Post
    here is an interesting observation I had so far...
    For the last few batches of beans I have roasted and bought, they have been getting very good results and flavours coming out...

    I just made a batch of "what green beans do I have now" blend that was made up of Java, Ethiopian and Peru I had... roast came out pretty dry... from day 1 after roast, after I grind it into my VST basket and tamp it, it felt "crunchy" as I pressed down... felt the grind and wasnt moist and clumpy... more like stale grind texture...

    so the shot came out like a nice rat tail for the first 5 seconds and then it would gush out and blonding very quickly after that... has a nice Guinness stout effect but the crema dissipate very quickly after... had a look at the puck and it shows some chanelling along the edge of the basket... flavour wasn't too sour... just tasted flat

    My work flow hasnt changed, so I guessing its the beans this time thats giving me grief?
    How old were the green beans?

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  • okitoki
    replied
    here is an interesting observation I had so far...
    For the last few batches of beans I have roasted and bought, they have been getting very good results and flavours coming out...

    I just made a batch of "what green beans do I have now" blend that was made up of Java, Ethiopian and Peru I had... roast came out pretty dry... from day 1 after roast, after I grind it into my VST basket and tamp it, it felt "crunchy" as I pressed down... felt the grind and wasnt moist and clumpy... more like stale grind texture...

    so the shot came out like a nice rat tail for the first 5 seconds and then it would gush out and blonding very quickly after that... has a nice Guinness stout effect but the crema dissipate very quickly after... had a look at the puck and it shows some chanelling along the edge of the basket... flavour wasn't too sour... just tasted flat

    My work flow hasnt changed, so I guessing its the beans this time thats giving me grief?

    Leave a comment:


  • CafeLotta
    replied
    As the original thread was to do with channeling and not another VST basket debate, it would have been interesting to know if the original issue was one of a poorly fitting tamper. This would have been of much more use to people following the thread rather than another long winded VST discussion. It should have been moved to another thread or added to the many others on this topic.

    A VST basket in itself won't cure channeling but a correctly matched close fit tamper might, regardless of the basket.

    Leave a comment:


  • Yelta
    replied
    Originally posted by lucifuge View Post
    OK, an update...

    I am now using a Pullman Tamper with a matching 18g VST basket. I've probably pulled 20 shots since, (most for calibration) and not once was there any channeling at all!

    Today I gave my Rocky Rancilio Doserless a huge cleanout. Interestingly, the coffee coming out is clumping somewhat, but at 8 years+ or so old, that's not unreasonable. I'm probably due for a new grinder and really want a stepless one this time. Any suggestions, pls go ahead it would really help. I have my eye on a Eureka Mignon but that's it at the moment.
    Certainly sounds to me that the OP, Lucifuge had his channeling problem solved by post 33 when he invested in a Pullman tamper and VST basket.
    The thread remained pretty well on topic up to that point only then did it morph into (THE GREAT BASKET DEBATE)

    Leave a comment:


  • CafeLotta
    replied
    Originally posted by Pete39 View Post
    Perhaps we'll see those on this forum who believe they do "get it" at next year's WBC showing all the rest of us (who just don't get it) how its done.

    Good on you Cafelotta for trying to help solve the OP's problem. Unfortunately he's probably not even bothering to read this thread anymore.

    Apologies to the OP for the off-topic rant.
    I agree Pete. Its a shame that the OP had their thread hijacked along the way and was probably left wanting. Seems to be happening more and more here on CS unfortunately.

    It would have been good to know whether the OP had bought a matched close fit Pullman tamper/basket which may have explained the improvement in regard to edge channelling. The suggestion I made of the "12, 3, 6, 9 o'clock tamp was to test if his original tamper may have been too loose for the basket he was using.

    The advent of close tolerance Pullman, Reg Barber etc tampers has obviously helped to alleviate edge channelling when matched correctly to a decent basket.

    Leave a comment:


  • Journeyman
    replied
    Originally posted by blend52 View Post
    This might be plausible IF all the fines were the same size, but since by definition the fines are uncontrolled and random in size, then any variation in hole size is likely irrelevant compared to the variation in the size ( and shape) of the fines.
    Looking at this from purely a physics PoV, the consistency of size of the fines doesn't really come into it; it is the randomness of whether fines go through or block. What that means is parts of the basket will extract coffee as planned from above the 'good' holes, and other parts will either drop fines into the brew or fail to pass coffee. i.e. you wind up with an unevenly extracted puck.

    AFAIK the ultimate goal for a God-shot is to have the entire volume of grinds evenly extracted with grain size just right to extract the goodies in the 25 - 27secs allowed. To me that means any assistance in evening out the flow means I have a better chance of grinding to that point, rather than having random actions occurring in different parts of the puck.

    With even hole size instead of varying ones, I can set my grind to optimum for my bean/grinder etc. and be confident I will get consistent results from almost all the coffee in the basket.

    And it seems to work as stated above - I have been trying out some of the suggestions and noted results that agree with TampIt's comments. e.g. I can grind much finer with a VST and still get excellent results simply by dosing lower in the basket. e.g. A bean that gives good results at 12 - 13 on the scale can be ground at 8 and produce a syrupy extraction that almost coats the tongue with flavour. It does take about 30 secs or a little more to get my 60ml though, but there's no blonding - I think I mentioned earlier (or maybe in another thread) that while playing with grind etc I got a lovely coffee with a 60 secs extraction time.

    Dropping the grind size by that much with the SB basket produces a choker, even if I reduce the dose - and if I reduce the dose to the level I used for the 8-grind in the VST, the puck is all mushy in the SB but is still a one-tap, solid puck in the VST.

    And I get no channelling at all, which I'd put down to getting the naked PF and correcting my tamping accordingly.

    Leave a comment:


  • MrJack
    replied
    Originally posted by TampIt View Post
    Considering Vince Fedele's http://cdn.shopify.com/s/files/1/009...presso.pdf?134 was a April 2011 reprint of a much earlier paper he wrote, there is more than enough data & test results there to give anyone pause for thought (yes, I have put it and a number of related links into CS many times). It was written before he teamed up with La Marzocco to develop what eventually became VST baskets.
    It's an interesting article.
    There are a lot of conclusions (some of which I have reservations about), a bit of analysis, but not a significant amount of real data. There are also a few errors/omissions, some potentially misleading graphs a curious lack of any references relating to flow or mass transfer, and an even curiouser abundance of references to medical papers.
    That said, quite an enjoyable read (obviously not intended to end up in a technical journal or textbook!).

    I'd be interested in something with a bit more detail though, if you know of any?

    Leave a comment:


  • TampIt
    replied
    Originally posted by blend52 View Post
    Well, if you are going to be pedantic about it, then NO its not "raising the subject" ,
    .. Andy S... "raised the subject of fines" ,..
    ...my post was a REPLY to a statement about fines by journeyman.

    And no, i am not missing the ( more precisely YOUR) point either, but simply discussing other possible factors in the process.
    HI blend52

    I stand corrected. I was merely quoting MrJack's post, then yours. Probably not my brightest move as you are 100% right. Neither of you raised the subject of fines. Both of you commented on them.

    FWIW, I believe most of the confusion around VST's performance is linked to fines.

    Enjoy your festive season.

    TampIt

    Leave a comment:


  • blend52
    replied
    Originally posted by TampIt View Post

    Looks like raising the subject of fines to me, doesn't it to you.

    TampIt
    Well, if you are going to be pedantic about it, then NO its not "raising the subject" ,
    .. Andy S... "raised the subject of fines" ,..
    ...my post was a REPLY to a statement about fines by journeyman.

    And no, i am not missing the ( more precisely YOUR) point either, but simply discussing other possible factors in the process.

    Leave a comment:


  • TampIt
    replied
    Originally posted by Yelta View Post
    Morning Tampit.

    Learning all the time! perhaps my Mazzer Mini is the reason I'm less than excited about VST, maybe I need to trade it in on a Sunbeam.
    Afternoon Yelta

    Recently, I spent a close to a whole day cleaning out & recalibrating a Mazzer SJ to try to get it to grind fine enough to get a good result out of a VST: with very limited success. Considering SJ's are designed for traditional espresso grinds and coarser, whilst VST appreciate quite a bit finer than that range I do not blame Mazzer for not being capable of operating outside their manufactured spec. No more than I would blame a mini car for not towing 100 tonnes of iron ore easily.

    Even my current RR45 can only manage it for a short while after I do an A to Z cleanout and recal. It is supposed to be able to go down to Turkish grinds (and does) however it still generates more fines than VST's appreciate after a few shots. When I make Turkish in my Ibrik (dark roast w added sugar & cardamom, traditional "multiple heat and damp down three times" method), I presume the fines just form part of the mud, so they do not matter too much in that environment. Or the three tonnes of sugar & added cardamom some masks the bitterness.

    FWIW, I just see the whole issue as a simple case of a new technology in one area creating problems in a different part of the chain.

    I have not used a Mini for a while, however I recall it was around the same particle size variation as its big brother. I guess it would probably give the same result. Maybe. YMMV.

    If you can access one, try a Vario gen2 or an HG one: either work with a VST with almost contemptuous ease. You can tinker & figure it all out from there to your hearts content. I suspect next years Mazzers will also do so.

    All the best for XMas & NY in South Oz.

    TampIt
    PS: Oh, and yes, one of my calibrated EM480's worked better in the same Linea using the same grinds with a VST than the SJ did after my work. Paper test showed less fines from the 480. Not that I would suggest you go through the grief of calibrating a 480 (shimming: easy. Full calibration and semi stepless mod: not for the faint hearted). Ironically I used my RR45 to calibrate the 480's before I bought my VST's. Now the 480's keep the RR45 on its toes in terms of VST use. Still gives me a wry grin.
    Last edited by TampIt; 17 December 2013, 05:59 PM. Reason: Forgot the cardamom...

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