Consistent channeling [UPDATE]

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brianl
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#1: Post by brianl »

Hello,

I've read through the guides but I still have some issues with channeling and i'll first start with my routine.

I use an aluminum cup and fill it with 18g (one spray off water from a bottle that generates a pretty fine mist and shake the beans/cup). I then grind into the HG One tumbler. I place the tumbler on the cleaned portafilter and stir the grinds in the tumbler with a glass straw about 5 times. I drop the grinds into the portafilter by pulling the plug and tap once on my tamp stand, try to level out with my finger and tap once more. I then do a 5 lb or otherwise light tamp to get the puck level. I tamp down and do a 90 degree turn with pressure. I usually tamp it two or three times until there are not many stray grounds on the coffee bed or the tamper base. Then its locked and loaded. It seems like the dry puck will have a pinhole in it and this generally lines up with a thin and sourish shot (channeling). I've tried with both a flat and convex tamper. I don't get gushers and the end weight usually matches up with the times I don't get the pinholes.

I dose by weight so it seems that the basket is usually underdosed and its hard to really level with a finger. If this is evident, should I really be continually adjusting the dose or basket so I can sweep/level with my finger? I heard that the stray grinds on the coffee bed make no difference but I'm pretty OCD. Should I just try my best to just do the light tamp to level and then one full pressure tamp (90 degree turn or not)? I've tried it a couple times and didn't notice a difference but it could have been a range or other things that negated its benefit. In regards to stirring in the HG One tumbler. I may try to stir after releasing into the basket (after pulling the plug).

The bottomless portafilter I have used a couple times and there is some light spritzing on occasion but otherwise I mostly use the single spout to avoid getting everything messy. I have also had the HG one for a few weeks and have used it daily with grinding about a lb of stale grinds before first use. I would had to blame new burrs after this but I thought i'd mention just in case.

Thanks in advance.

VisionScientist
Posts: 28
Joined: 10 years ago

#2: Post by VisionScientist »

I suggest you try without turning the tamper. Just tamp straight down. Twisting with pressure can definitely fracture a puck. If you spin the tamper, do it with no downward pressure.

I assume that you are using good, fresh coffee beans.

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thomas5267
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#3: Post by thomas5267 »

Are you using coffee beans that were roasted within the last month? If not, that's probably why you get channeling. Fresh coffee makes a huge difference in both taste and the look of the pour.

Secondly, don't twist the tamper while applying pressure. It will ruin the distribution and cause channeling (or so I am told).

brianl (original poster)
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#4: Post by brianl (original poster) »

I am using Gaslight Coffee Roasters on the 4th day post roast.

I'll work on the tamp after work and post an update.

I got to thinking more about the under dosing and putting 18g in a triple IMS basket might be too little. I may try the 18g VST with the VST tamper. I might want to adjust my tamping first. You you, change one variable at a time. This is a light roast so it's a finer grind that usual ( but i was having this problem with Red Bird espresso, which is definitely further into the roast).

Maybe an Aside, but is the main purpose of the VST basket for third wave orange juice espresso? This is currently the type of bean i'm using. Ie, these types of coffees typically require a fine grind to be adequately extracted and the VST provides the ability to use this finer grind?

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keno
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#5: Post by keno »

As a new HG one owner I recall reading about this as an issue that some users were experiencing. Apparently this problem tends to resolve once the grinder is adequately broken in.

See for instance this post: Owner experience with HG one grinder

Have you run any minute rice through your grinder to expedite the break in process? Have you checked the alignment of the burrs? This is now fairly easy to adjust on the new 2014 models.

Finally, how do your shots taste? If they taste good I wouldn't worry too much about it. Just keep using and monitor the grinder and it will likely improve over time.

brianl (original poster)
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#6: Post by brianl (original poster) »

I taste every shot no matter what it looks like, ha. They are consistenly thin, even using the redbird (I did manage to get lucky and have some thick ones but in kind of a runt at the moment). Therefore, it's definitely something that needs to be improved.

I have not run any rice through, but it's probably the equivalent of 3-4 lbs of coffee by now. I have not checked the alignment but will look into that. Is there a specific procedure for this or is it a bunch of eyeballing?

mgrayson
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#7: Post by mgrayson »

One clue to misalignment in the HG-One is a layer of fine powder sticking to only one side of the funnel - a strip about a half inch wide running around one half of the funnel after grinding a shot. After aligning the burrs (more by feel than by eyeball - the instructions on the website are maddeningly vague), the strip went away and the grind felt better. For me, channeling happens when I don't do a consistent WDT when dropping the coffee from the blind tumbler into the PF.

I make no claims to expertise here, but this has been my recent experience.

--Matt

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keno
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#8: Post by keno »

brianl wrote:I have not run any rice through, but it's probably the equivalent of 3-4 lbs of coffee by now. I have not checked the alignment but will look into that. Is there a specific procedure for this or is it a bunch of eyeballing?
3-4 pounds of coffee is nothing. I would try running a few 14 oz (400 gram) boxes of Minute Rice (make sure it is Minute Rice which is precooked) to expedite the break in process. Seems like most people who use a few boxes report pretty good results.

Regarding alignment, remove the lower funnel and look at the gap between the upper (female) and lower (male) burrs. Using a small flashlight from the other side can help you see if it appears even all the way around when dialed in for espresso. If it looks out of alignment then follow the HG one instructions here:
http://hg-one.com/the-hg-one-grinder/ca ... alignment/

Finally, spend some time dialing in the grinder. And definitely do not use a triple basket with only 18g. If you have an 18g VST you are better off with that.

Good luck!

Exordium01
Posts: 201
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#9: Post by Exordium01 »

If you aren't using a bottomless portafilter, how do you know if it's channeling? It sounds more like your grind is too coarse. Are you weighing the shot?

brianl (original poster)
Posts: 1390
Joined: 10 years ago

#10: Post by brianl (original poster) »

I never said I didn't use the bottomless and puckology is worthless mostly except for when it comes to pinholes I think. Therefore I'm sure it's channeling from limited use of bottomless and the pinholes.

My grind is not too coarse as Ive said the output is where I want it so it could only be too fine.

My original post says I weight it. Both input and output.

The bottom of burr has fine grind stuck all around the circumstance. Looks like if adjusting tamp tech fails I'm off to the grocery store.

Thanks everyone!

Update: Switched to the bottomless again, 18g in 18g VST basket. Regular tamp with no twist and no polish! The result is a beautiful shot that tastes amazing. I knew starting this topic would jynx me! trying for two in a row tomorrow morning -crosses fingers-

Sorry for changing 2 variables instead of just one but i pretty much convinced myself about the tamp twist and that i was underdosed too much.

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