Unavoidable channeling with new blend?

Beginner and pro baristas share tips and tricks for making espresso.
DaveC

#1: Post by DaveC »

Reading your post wasn't sure if the machine had a 3 way valve or not, watching the video, looks like it doesn't. This does mean it's easier to get a wet puck, but should be no problem getting dry pucks...I hav done it with an Isomac Supergiada, which also has no 3 way valve.

Watched the Video, about 40-45 second to extract 1oz from what looked like a double basket?

If so this is a little long and also low on volume. For a double basket aim for 2oz in around 25 secs, for a single basket about 1 oz in 25 secs. So whichever your using, you look to be grinding too fine. This also makes it real hard for the excess water to drain from the PF after the shot ends and why you get the dribbling and probably minor sneezes when you undo the PF (especially if you do it quickly).

I think trying a coarser grind will help a lot.

Here is a video of a "just passable" extraction using a single basket and 1oz extracted for comparison if it's of any help.

«missing video»

Dave

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Marshall

#2: Post by Marshall »

oofnik wrote:First of all I want to say how awesome the HB forums are! I've learned quite a lot from just browsing around and reading over the last few months. So, thanks. :D
Indeed, it does look like you've learned quite a lot from the tinkerers here, but mostly the wrong things. Fine tuning a machine is great fun and can help take you from, say, 90% of what the beans are capable of to maybe 95%. But, first you have to develop the skills to get to 90%. One of those skills is recognizing that every blend and every roast is different and that even the same roast will behave differently, depending on humidity, age and the phases of the moon.

If your usual grind doesn't work on a new blend (assuming it is fresh), put the meters aside and focus on adjusting the grind until it at least looks right. Then work on distribution and tamp. When you like what you're getting, that is the time to play with your bells and whistles, and see if you can make it great.

Oh, and Andy S is the creator of Frankensilvia.
Marshall
Los Angeles

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oofnik

#3: Post by oofnik »

DaveC wrote:Reading your post wasn't sure if the machine had a 3 way valve or not, watching the video, looks like it doesn't. This does mean it's easier to get a wet puck, but should be no problem getting dry pucks...I hav done it with an Isomac Supergiada, which also has no 3 way valve.
You're right, the machine does not have a 3-way valve. I wonder why it's so rare that I get dry pucks.. perhaps there is some other factor that affects this other than the dose, tamp & grind? I've played with all three quite a lot, and even good shots had wet pucks in the end. Hm.
DaveC wrote:Watched the Video, about 40-45 second to extract 1oz from what looked like a double basket?
The extraction was actually 31 seconds from the time the pump was turned on. I stopped it when I noticed the flow going blond. In retrospect it should probably have been stopped a little earlier, but the camera messed with my timing. And yes, it is a double basket.
DaveC wrote:If so this is a little long and also low on volume. For a double basket aim for 2oz in around 25 secs, for a single basket about 1 oz in 25 secs. So whichever your using, you look to be grinding too fine. This also makes it real hard for the excess water to drain from the PF after the shot ends and why you get the dribbling and probably minor sneezes when you undo the PF (especially if you do it quickly).

I think trying a coarser grind will help a lot.
I tried changing the dose down from my usual 17 grams or so all the way down to 14 but the puck still hits the shower screen. I know the shot volume should be closer to 2oz, and I've made the grind much coarser than I've ever had to for any other blend. That is why I'm hesitant to adjust it even farther; I think there is something else that is off here. And just for good measure, I remeasured my tamp on a scale and it's right on.

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another_jim
Team HB

#4: Post by another_jim »

I've tried reading the original post, but kept getting lost in all the seemingly irrelevent excursions.

I always pull freshly roasted coffee, but most people don't. Basically, it's gassy, blondes quickly, and has a huge amount of too bubbly crema. The best technique is to grind extra fine and go for ultra-ristrettos. The looks aren't great, but the aroma more than compensates.
Jim Schulman

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cannonfodder
Team HB

#5: Post by cannonfodder »

First off, don't worry about how the puck looks when you remove the portafilter. Not having a 3-way valve will cause that soupy mess. When you unlock the PF and allow the pressure to vent out like that, the puck gets blown all to pieces. In my bench work on the Gaggia Achille I get similar results. To check for proper headspace try this little trick. Grind/dose/tamp as you normally would. Take a penny (assuming you are in the USA) and place it on the surface of the puck in the center. Now lock your PF in, and then remove it. If the penny is now pushed down into the puck, you do not have enough headspace and need to down dose. Once again, this is a general guideline. Different machines prefer different headspace but this is a good starting point.

On your video, you had several large dead spots on the basket. When the espresso starts to flow, it should flow evenly across the entire surface of the basket. Dead spots are a tell-tell sign of bad distribution. Your grinder is capable, however the Caribou coffee could leave a bit to be desired. Most chain coffees tend to be past their prime.

The grind will change not only from blend to blend, but batch to batch and hour to hour in some cases. Humidity plays a big role in espresso IMHO. Some days I change the grind for nearly every shot.

As Marshall points out, the machine is the smallest factor in the process. While some machines perform better than others, a skilled Barista can make the most of whatever they are using. The largest delta in the formula is on the handle side of the portafilter. It takes time to learn but you are moving in the right direction.

Personally, I would recommend keeping away from Caribou (unless their roaster is local and coffee roaster in the past 3 days) and revisit your distribution method.

You have probably seen them, but if not you may want to look at the Videos of espresso extractions and Tamp and Dose Techniques Digest
Dave Stephens

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oofnik

#6: Post by oofnik »

Thanks for the helpful hints Cannonfodder. I'll try the penny method before my morning shot tomorrow.
As far as the video, yes I know the distribution was not very good. Normally however I do get a pretty even flow. I believe it's mostly because of the very low dose I used, about 14 grams - it was about 3mm from the rim of the basket before tamping. I couldn't really even it out with my finger. But regardless, it still expanded and pushed up to the showerhead bolt during the shot. I'm thinking that's bad.

The video was actually of SM Liquid Amber, roasted 5 days prior to about FC+. The roast came out uneven, as evidenced by the bean pic. Maybe that threw things off, I don't know. But as far as the Caribou coffee, I've got a hook up at the store. They get their coffee in 5lb bags and they actually have the roast date on them. My friend tries to get me a 1/2 lb every now and then when the new shipments come in and it's usually 5 - 10 days after the printed date.

Anyway I just ordered 1 lb. of Black Cat. Should be in sometime this week, so by pulling shots with some professionally roasted stuff I'll be able to tell if my roasting is out of whack.

Marshall, I realize that the gauges and meters are not all that there is to making great espresso. I am by no means an expert when it comes to the user variables, but over the last several months I like to think that I have at least improved a little bit. Also, I'm fairly certain that going from a thermostat-controlled, pressure-unregulated machine with a temperature hysterisis of 30 deg. C to what I've got now would make it a little easier to control the user variables without worrying about what the machine is doing. I see it as having less to worry about so I can focus on the things I need to focus on. Wouldn't you agree?

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Marshall

#7: Post by Marshall »

oofnik wrote:Marshall, I realize that the gauges and meters are not all that there is to making great espresso. I am by no means an expert when it comes to the user variables, but over the last several months I like to think that I have at least improved a little bit. Also, I'm fairly certain that going from a thermostat-controlled, pressure-unregulated machine with a temperature hysterisis of 30 deg. C to what I've got now would make it a little easier to control the user variables without worrying about what the machine is doing. I see it as having less to worry about so I can focus on the things I need to focus on. Wouldn't you agree?
My concern was your focus on equipment. There is a tendency on these forums to blame the equipment whenever something goes wrong and look for a mechanical or electronic solution. I think that's fine (or at least less problematic) for someone who really knows their way around espresso. I think it's a major distraction for anyone who is first getting into it.
Marshall
Los Angeles

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cannonfodder
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#8: Post by cannonfodder »

oofnik wrote:But regardless, it still expanded and pushed up to the showerhead bolt during the shot. I'm thinking that's bad.
But how do you know it is doing that? Without a 3-way, what you are seeing may be a side effect of the puck blowing up when you loosen the portafilter to depressurize. Under normal circumstances, a very light impression of the shower screen/screw is normal.


After the shot
Dave Stephens

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oofnik

#9: Post by oofnik »

cannonfodder wrote:But how do you know it is doing that? Without a 3-way, what you are seeing may be a side effect of the puck blowing up when you loosen the portafilter to depressurize. Under normal circumstances, a very light impression of the shower screen/screw is normal.
Even if I wait a few minutes for all the pressure to release, I'm still left with a mess.

Anyway my pound of Black Cat came in today, and I truly, honestly have run out of ideas. There is a limit to how many grind settings, how many tamp pressures or distribution techniques I can try before I have to stop for fear of caffeine overdose. Today I reached that limit, and my shots did not improve one stinking bit. I'm really kind of frustrated and clueless right now. The way I understand it is that there are two components of making good espresso: there's the scientific, quantized side, where you have brew temperatures, tamp force, pressure, dose, preinfusion time, etc. On the other side you have the 'zen' part, as I like to call it, which is itself a combination of experience and a level of intuition shared by artists, chefs, musicians, and people who are generally very good at that sort of thing. Both contribute to making excellent espresso. As someone who has been fascinated by science my entire life, I'm afraid I've leaned a little too far to the quantization of espresso and haven't given enough time and practice on my zen. Either that, or I'm just cursed and there's absolutely nothing I can do about it.

What really irks me however is that I used to get shots looking like
Image
, using the built-in grinder (similar in quality to a Solis Maestro), before the pressure mod, before the PID, before I roasted my beans, before I even knew what the WDT was. And now that I have all this stuff that's supposed to help me make better coffee, all I get is crazy channeling armed with an arsenal of spewing jets every time despite a consistent distribution technique, a good solid tamp, and a $270 grinder. It really makes me think.. maybe espresso just isn't for me.
And the worst part is, I keep trying to justify it by making the excuse that my machine isn't good enough and I need to plunk down $700 on something better. Maybe my tamper is at fault? Maybe my filter basket isn't the proper shape? Maybe my group head isn't allowing the correct preinfusion? Or or... But I know it's just me. Only problem is, after eight months of this, all I've done is gotten worse. Unless someone can convince me to keep trying I'm probably going to either go insane or put the equipment up for good. Today sucked. :evil:

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HB
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#10: Post by HB »

Whew! I just re-read this thread and can relate to what you're saying. I've had days like this, usually right after an equipment change. If it lasts too long, I take a break. But before you do, let's review the problem at hand:
oofnik wrote:The pressure mod, however, has changed the behavior of the machine quite a lot, and I'm at a loss trying to figure out what's going on here.
oofnik wrote:And now that I have all this stuff that's supposed to help me make better coffee, all I get is crazy channeling armed with an arsenal of spewing jets every time despite a consistent distribution technique, a good solid tamp, and a $270 grinder. It really makes me think.. maybe espresso just isn't for me.
My first thought reading your last entry was "crazy channeling with no obvious barista technique failures = pressure is too high." That's how I created this beauty:

Image
System meltdown from
Perfecting the Naked Extraction


But you presumably have that angle well covered with a gauge showing realtime brewhead pressure (?). If you have a pressure gauge off a tee near the pump, also check it at the grouphead with a pressure portafilter. And just for kicks, try dropping the pressure to six bar. That should be equivalent to a "chip shot" in golf in terms of extraction difficulty. The crema production and body will drop, but you should at least have a reasonably drinkable espresso, which you clearly deserve.

Other ideas are welcome...
Dan Kehn