# Vostok Evo -constant channelling shots



## Paolo5 (Sep 29, 2012)

*H-E-L-P !!!!!!*

I am having real problems getting good shots with my Evo.

*I am using the same beans, grinder and technique that I use with other machines and get even extractions from them all...all except the Evo.*

*I am hoping that other Evo owners can shed some light on what I am doing wrong...or what the problem could be.*

I use/do the following-

*IMS basket B662TH32M (but have also used the LSM double basket)

*20gm medium roasted coffee one week post-roast

*Lagom P-64 and Helor Stance Motor grinders

*WDT and RDT

*level with 54mm OCD-type gizmo

*tamp with JoeFrex click-type tamper (The ACS one in the equipment box was a 58mm tamper, so I am using another tamper with the LSM basket that is possibly on the large size...it just fits...have ordered another one)

*Group temp. 92C (at the moment)

*Boiler temp. 98C (at the moment)

*Lever down for first drip or 10 seconds (whichever comes first)

The shot attached is typical of what I am getting.

I would appreciate any help and guidance that anyone can give..

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View attachment P1120467.mp4


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## The Systemic Kid (Nov 23, 2012)

First off - what does the shot taste like? If you are pleased with the result - the extraction issue is cosmetic. If extraction is a problem, e.g. under-extracted, would take a closer look at what's happening when you get spraying towards the end of the shot.

During PI, there is a noticeable differentiation in how the extraction beads - it starts very predominantly on the left and side where the spraying emerges later. This suggests water travel through the puck bed is uneven - when you let the lever go, bulk of the shower screen is not beaded which indicates there is some channeling going on. Would recommend leaving the spent puck in the group for a few minutes to dry out and then tap out and examine a cross section to check for evenness of extraction and pinholing. If the puck cross section colour is even, i.e. no dark areas, extraction is OK.

As part of your prep routine, after dosing the portafilter, do you give it a sharp tap to level the grounds and sink any caves? If not, might be a good idea to try this but only do it once. It's unlikely but worth a note - when tamping, it's possible to exert more pressure away from the portafilter side due to the way the tamper sits in the hand.


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## 4085 (Nov 23, 2012)

@Paolo5 I would be proud of that shot!


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## Paolo5 (Sep 29, 2012)

Thanks, guys..

Gees, Dave...

You wouldn't be proud of it...trust me!

The shots are underextracted...tasting weak and insipid.

I DO give the p/f a few sharp taps on the tamping mat prior to levelling..and then I tamp. I will try just one tap.

If I do EXACTLY the same prep in a 58mm machine that I have, I get a great shot.


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## Stevebee (Jul 21, 2015)

I know it channeled at the end, but what weight was in the cup in how long?


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## 4085 (Nov 23, 2012)

@Paolo5 Do me a favour, and this is no fix.....try using the single spouted pf for a couple of shots and working on taste alone, compare them


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## The Systemic Kid (Nov 23, 2012)

Dialling in Square Mile Sweetshop - first attempt. Went a bit too fine. Some sprtizing but shot unaffected, taste-wise. Talking of spritzing - seem to get this depending on the bean but doesn't seem to affect the shot, i.e. lead to under-extraction.






Puck doesn't show any sign of channeling - dark edges are in the stock basket's dead zone. Waiting on some IMS to see if they make any difference.


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## Stevebee (Jul 21, 2015)

All my gawd! Don't see any videos for ages and then two come along like buses and both show significant channeling!

Hope this not a trend as mine hasn't even arrived yet. Don't see shots like that on either my Decent, Vesuvius or my L1 so hope that's not the norm. Didn't expect it as I thought the deeper basket would kinda offset the higher pressure. Obviously depends on roast level, grinder, burrs etc.. so will wait until mine arrives to see


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## The Systemic Kid (Nov 23, 2012)

Not significant channeling - if it had been, would have shown up in the puck. Beans were a little fresh for espresso but the shot tasted great - not under-extracted.


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## Stevebee (Jul 21, 2015)

Looking forward to getting mine but not long to the August shutdown so we'll see


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## Denis S (Jul 31, 2020)

@Paolo5 start looking after min 5:00:


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## Paolo5 (Sep 29, 2012)

Thanks Denis..the video was very informative to me.

I will try puck raking tomorrow.

(I made 3 Evo coffees today that didn't channel so I am really encouraged to keep at it.)


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## Stevebee (Jul 21, 2015)

Using a puck rake makes such a difference. Good luck


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## Denis S (Jul 31, 2020)

You have to somehow level the puck density in the basket, because with such high pressure and unforgiving force from the spring lever, you end up with channeling due to uneven puck density.

Do WDT, tap once and observe how level the puck is before tamping, if you have one spot that has less coffee that is gonna channel/let water go there easier.

The rest of the machines might not have the same 9-11 bar pressure or it might be that you need to change something you doing on the Leva (tamping force, grinding directly into PF versus grinding into a cup and transfering, WDT/rake) and stuff like this.

It is also important how much headspace you have left, for example if you have the puck not touching the group, when it inflates and touches the shower screen it can channel because it will touch first in one point. Just buy 1-2 kg of cheaper fresh coffee and pull shots untill you figure out what's wrong and what works. Throw everything to the sink and then you are good to go.

I know for sure 6 bar shots are easier to pull compared to 9-11 bar shots.


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## Paolo5 (Sep 29, 2012)

I just made 3 coffees with the Evo using my WDT tool as a puck rake.

I am quietly thrilled that the shots had no visible signs of channelling! And they tasted correspondingly richer.

The first signs of coffee did show first around the edges of the basket each time....but the centre filled within 2 seconds or so. No spurts or vacant real estate on the basket bottom. I need to practise this 'new' (to me) technique.

Again, Denis...thanks for the tip!


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## GrahamSPhillips (Jan 29, 2021)

I've added a puck screen to my Vesuvius. The difference in the pour has really surprised me... and yes it tastes better too!


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## 4085 (Nov 23, 2012)

I have gone back to a single spouted pf. Only puled one shot so far, an americano for breakfast. The pour was good, thicker than I remember and taste was spot on


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## Denis S (Jul 31, 2020)

For a higher/even extraction it is desirable that the shots starts a bit earlier from outside. There is a radial extraction going on in the coffee puck where the middle part get's extracted more while the outer rim (where most baskets lack holes) is extracted less. So for a equal extraction in the puck (and a higher one) you want a slight off-set in the start of the shot on the naked, starting from outside first.

If you do not want for this to happen, you can with your WDT tool, rake the grinds from outside inwards, forming a small pile of grinds in the middle, then tamp on that and you will have a even starting extraction on the naked pf. It depends what you like, I go by taste.

WDT tools are good, but make sure you do not use really thick needles, because thole will let channels behind where the water will go first. We use needles that are in between 0.25 and 0.4mm thick. And please, do not use the WDT tools that have the tips bend, those are even worst.


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## Like Medium Strong Coffee (Feb 18, 2021)

I experimented something really crazy this evening! I may even be shredded to pieces for trying this out of the mind shot. I wanted to see how much I can stretch this beautifully designed and produced machine.

*My shot on the Evo took 4.5 mins! 🤣 *

The machine is just 2 days old and the shots from this machine is fantastic.

Mystery 14, Jx Pro grind setting was 1.25 (almost at the lower end of espresso setting), 21g on the double stock basket, which was only 65%-70% full, levelled it with fingers, a couple of gentle side taps, good tamp and cocked the lever.

The group head temp was 93.5C and the brew boiler was 101.5C.

The PI lasted a minute for a few drops to fall on the cup, I released the lever, the pressure went to 10.5-10.75. The flow was obviously significantly slower. The pressure did drop at a slower rate until 5.5 bar pressure and quickly slided towards 0 after that. I cut the shot out at the 5.5 bar pressure. The shot weighed at 48.7g.

As far as the most important factor - taste - was concerned, it was smooth, had a nice fruit acidity, good to drink but obviously it left a bitter (little paracetamol bitter) after taste. I thought it won't be drinkable. This did surprise me. On a scale of @MWJB's 9, I will give a score of 6.5 or max 7.0 out of 9. It was meant to be a shot for a milk-based drink. With milk, the coffee was actually very good. 😊

I wish I had a tool to measure the EY and TDS. I know what Mark will comment! 😂

Unfortunately, I did not shoot the video. But, please take a look at the the broken puck! The dark circle on the right was the circlip impression. Looking at the left, I thought the extraction wasn't even.

Obviously, I will be loosening the grind either to the morning levels or grind coarser than that from tomorrow; I do not have plans to repeat this experiment.

Sorry, if any one finds this experiment offensive or not worth posting. 😊

Obviously, happy to read any comments, however critical they may be. Thanks for reading folks 😊.

Cheers!


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## rusty pie (Feb 5, 2021)

Interesting read. My experience with the Evo is along the same lines: no matter how bad I get the dialling initially, shots are always drinkable. The first shot I pulled with it took around 80 seconds for a 1:2 ratio, but it was still very sweet compared to what I was used to before!


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## Like Medium Strong Coffee (Feb 18, 2021)

rusty pie said:


> shots are always drinkable


 I think this is clearly down to the features / characteristics of the machine coupled with, might be, the size of the basket. Happy to be corrected.


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## Paolo5 (Sep 29, 2012)

An update:

No more channelling...My ego hates to admit this but problems that I had were all due to pilot error.😝

For the past 3 weeks or so I have had nothing but fabulous shots from my Evo.

A very happy Evo camper!😁


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## Eiffel (Apr 3, 2021)

@Paolo5, would you mind telling us what was the "pilot error" you were making, as this might others avoid it ? Thanks.


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## Denis S (Jul 31, 2020)

No or minimal puck prep for 10.5 bar shots.


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## Levvieman (Sep 14, 2021)

I seldom have channeling.

Made this quick one. Coffee is one hour old Malabar. Just roasted it and haven't adjusted my grinder to the new coffee yet.

I never use the naked becauseI always pull two seperate espressos.

Grind is off a bit but not much canneling. Little donut but who cares. Shot tasted too fresh of course.

I never level the coffee or do WDT.Grind into the portafilter and tamp the pile of coffee flat and lock in.


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## Denis S (Jul 31, 2020)

But yours is not an Evo, it's a totally different machine, with a different temp, different water path, different group temp.


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## DavecUK (Aug 6, 2013)

@Denis S you forgot preinfusion speed and pressure


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## 4085 (Nov 23, 2012)

@levvieman

Grind is off a bit but not much canneling. Little donut but who cares. Shot tasted too fresh of course.

I never level the coffee or do WDT.Grind into the portafilter and tamp the pile of coffee flat and lock in.

*A man after my own heart!*


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