Problem with channeling? Dose less and grind finer

Beginner and pro baristas share tips and tricks.
Ken Fox

#1: Post by Ken Fox »

da gino wrote:I was lucky enough to attend.

I had four shots - two from each grinder, and three of them were remarkably similar, all earning A's. The fourth was quite good, but had a slight note of bitterness. I hadn't watched the pour, but Dan told me when I commented on the shot, that there had been a little bit of channeling on that shot.

I could never expect 3/4 shots at home to be so similar, but I don't know if I should attribute that inconsistency to the grinder, the machine, or me (my guess is the last two are the biggest contributors more than the grinder).
Channeling seldom happens when shots are not "updosed." I would assume from the above that Dan was using a relatively large dose for this testing, which may be fully appropriate since the blend is likely designed for that.

Nonetheless I want to add that I have basically no experience with any of the grinders I've commented on using doses above 15g. I drink almost exclusively single origin espressos, mostly made from African dry processed beans (mostly Ethiopian or Yemeni in origin), although occasionally I'll add in 20-25% of an aged Sumatran to a coffee that either is or has aged to become uninteresting or unidimensional. In any event, I dose 14g virtually all the time, except if I'm at the end of a grinder fill and can anticipate a quicker pour, in which case I'll updose slightly to around 15g to salvage the shot.

I forget about channeling as a cause of sink shots because I basically never experience it anymore with my 14g basket doses. What impact, if any, that different sorts of grinder designs have on channeling is unknown to me since my dosing is standardized towards the lower end of what most people on this forum probably use.

ken


...split from Compak K10 WBC vs. Mazzer Robur taste test by moderator...
What, me worry?

Alfred E. Neuman, 1955

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HB
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#2: Post by HB »

Ken Fox wrote:Channeling seldom happens when shots are not "updosed." I would assume from the above that Dan was using a relatively large dose for this testing, which may be fully appropriate since the blend is likely designed for that.
No, I didn't updose and it wasn't a sinkshot by any measure, more like a SCAA rated 2.5 or 3.0 instead of the others which were +3.5.
Dan Kehn

da gino

#3: Post by da gino » replying to HB »

Agreed, I've certainly made/drunk my share of sink shots and this wasn't one and wasn't close to one. Since I wasn't familiar with the SCAA ratings I was calling it a B instead of an A, where a sink shot would have been a D or an F (I still consider C a reasonable grade). It sounds like +3.5 is what I was calling an A and 2.5/3.0 was what I called a B, which makes sense. Like I said, I'd have been thrilled with it if I'd ordered it at a cafe and very pleased if I made it myself.

Speaking of which, it is time to go pull a shot - here's hoping for an A or a B!

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malachi

#4: Post by malachi »

Ken Fox wrote:Channeling seldom happens when shots are not "updosed." I would assume from the above that Dan was using a relatively large dose for this testing, which may be fully appropriate since the blend is likely designed for that.

Nonetheless I want to add that I have basically no experience with any of the grinders I've commented on using doses above 15g. I drink almost exclusively single origin espressos, mostly made from African dry processed beans (mostly Ethiopian or Yemeni in origin), although occasionally I'll add in 20-25% of an aged Sumatran to a coffee that either is or has aged to become uninteresting or unidimensional. In any event, I dose 14g virtually all the time, except if I'm at the end of a grinder fill and can anticipate a quicker pour, in which case I'll updose slightly to around 15g to salvage the shot.

I forget about channeling as a cause of sink shots because I basically never experience it anymore with my 14g basket doses. What impact, if any, that different sorts of grinder designs have on channeling is unknown to me since my dosing is standardized towards the lower end of what most people on this forum probably use.

ken
Ken...
Have you wondered if your lack of channeling might be due to your choice of coffees rather than your dosing philosophy?
Do you think it's possible that your near exclusive use of natural and aged coffees (and it seems like largely low elevation softer beans) is actually what is driving your dose model?
It would be interesting to see what kind of results (both flavour and extraction) you would get from a high grown washed central american.
"Taste is the only morality." -- John Ruskin

Ken Fox

#5: Post by Ken Fox » replying to malachi »

Hi Chris,

The only washed central I'm using right now for SO espresso is Bolivia Cenaproc, and I'm dosing it the same. I have previously used Brazil Yellow Bourbon similarly. In both cases I used 14g doses with the same methodology, and don't recall any problems with channeling. There aren't a whole lot of washed coffees I've had that worked well for SO espresso, so my own experience with this isn't extensive. The only blending I'm doing now is very simple and generally consists of a dying or dead dry processed African spiced up with an aged Summatran, e.g. not your standard blend whose backbone is a washed Brazil.

Jim Schulman, a long time ago when he was suggesting to me that I try dosing in this ~12-14g range, told me that his observations were that channeling was basically impossible with lower doses, and that has been my observation in the last year, at least with my equipment. I qualify this by saying that one of my machines is a vibe (with a "naturally slow" pressure ramp up) and the other, a rotary, has been modified to preinfuse with regulated line pressure (~3.5 bar) for 6-7 seconds. In neither machine is the puck blasted with 9 bar from the first second . . . .

ken
What, me worry?

Alfred E. Neuman, 1955

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malachi

#6: Post by malachi »

Definitely would guess that the gentle pre-infusion is playing a part - of course - but would love to see what you thought of working with a coffee that's high grown washed. Something like the Guat Finca Semillero from Stumptown makes a nice SO espresso. Or even just a blend like the Hairbender that's really heavy in washed hard bean coffees.
"Taste is the only morality." -- John Ruskin

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another_jim
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#7: Post by another_jim »

Two Points

1: This argument about dosing and coffee choice is largely pointless. 14 gram doses using blends that are mostly composed of low grown naturals, done as roughly 25 second, 50 mL shots, are going to be a lot easier to handle, since espresso grinders, HXs and groups have been tuned to this particular style for 50 years now. There is simply no doubt about this.

One can also very successfully use higher or lower doses, different coffees, and different pour lengths or volumes. It's just going to require more technical acumen in setting the grinder and preparing the puck. How much more depends on the machine and grinder. Both the Cimbali and Elektra are a lot bitchier on dose than the E61s, LMs or Synessos (don't know about the new NS or LS or DC). This explains why Ken and us Elektra owners are more skeptical about updosing.

2: Personally, I would like to see espresso machines designed so that they can reproduce the taste balance one finds in brewed coffee with the concentration and mouthfeel of espresso. High end conical grinders get closer to this than regular grinders or the large planars I've tried. So that's what I use. The Elektra group at standard doses gets closer than the E61 at any dose (I don't have enough experience with the new generation machines to tell about them), so again that is what I use. Other general ideas about the perfect espresso will lead to other choices of grinder and machine.

This choice of equipment and grinder is based on my general purpose. So is the initial choice of dose and shot volume. I can vary dose and other shot parameters to tune for a given blend; if I were rich enough, I could even select machine and grinder (heck, one day I may be able to swap in the right taste buds and neurons -- they'll be included with the Illy pods). But every such departure from routine is extra work and takes me away from my best skill setting. So I need to be sure that the coffee requiring this departure is worth the extra effort. This is true for everyone working with a new espresso blend.

And this "worth it" takes us back to general desires. I'd drastically depart from my routine to get a good shot from an auction Kenya. But because that is what my gear is optimized for, it doesn't usually take a drastic departure. It does take a drastic departure to get the best from a Seattle style ristretto blend. And mostly, for me that isn't worth the effort, since it's not what I signed on for.

My moral here is simple. Everyone has routines that get the best results from the coffees they most enjoy; some are more focused in this than others. To get people to vary their routine, you can't just go on about being tolerant or adventurous. You have to communicate why a particular coffee or blend is worth the extra effort.


And now back to the grinder taste test

In these forums, we read a lot of opinions on equipment. The ones written by inexperienced people we all take with a grain of salt. However, we also have disagreements among very experienced people. When these happen, it is usually worth paying attention to what each person wants out of espresso (this is why I try to be upfront about my obsessions). In this grinder case, large planars like the Caimano or Vario have earned some accolades and some raspberries. So it is likely that they work well for some espresso styles, and not so well for others. Big conicals are on everyone's list as solid performers (although there's rarely any raving about godshots), so it is likely that they are useful across the espresso spectrum.
Jim Schulman

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HB
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#8: Post by HB »

For this site, I believe Ken's seminal thread Basket Overdosing; time for a serious re-evaluation! has influenced the standard diagnosis for channeling. Prior to his long-running thread, most experienced home baristas would suggest that the distribution was at fault; for many, the WDT became the near-universal solution to uneven extractions. I was among the WDT adoptees, though I understood it was a "grinder fix" from the beginning. As I gained more experience with larger conical commercial grinders during the Titan Grinder Project, I fully appreciated how much the WDT compensated for grinder shortcomings. Plainly stated, the WDT was a waste of effort for practically all of the TGP grinders. No wonder the pros who frequented this board scratched their heads over the enthusiasm for the WDT! It didn't help them because it addresses a problem that they didn't have in the first place.

However, to say that the solution to uneven extractions is "dose less, grind finer" is a bit oversimplified.

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Repeat after me: "Dose less, grind finer"

Yes, for some espresso machines - perhaps most - it indeed helps quite a bit. I assume the main advantage of dosing standard amounts (~14 grams for most espresso machines) is the proper headspace it affords, space that is eliminated if one doses more. This gap between the puck and dispersion screen allows for water to flow more evenly prior to full pressurization, potentially closing fissures as the puck expands. The same benefit can be had by using a deeper basket. For example, the so-called Synesso baskets easily hold 20 grams of coffee, but dosing them at 18 grams will allow for lots of headspace and it should help with the evenness of the extraction. Dosing a triple basket at double+ doses will leave tons of headspace, if you want to experiment with the tactile/taste profile at larger doses.
Dan Kehn

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malachi

#9: Post by malachi »

And... as noted earlier... I would be interested to see if the "dose less to avoid channeling" approach really works on high grown, washed, hard bean coffees (and, of course, what happens with the taste).

I still have a gut feeling that the answer is probably more accurately "upgrade your grinder" followed by "use forgiving coffee".
"Taste is the only morality." -- John Ruskin

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RapidCoffee
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#10: Post by RapidCoffee »

another_jim wrote:Personally, I would like to see espresso machines designed so that they can reproduce the taste balance one finds in brewed coffee with the concentration and mouthfeel of espresso.
Presumably you've experimented with lowered brew pressures? Using light pressure on a lever, I get a shot with the taste profile of strong coffee rather than espresso.
John