Vibiemme Domobar Super + Rancilio Rocky = Impossible? - Page 2

Need help with equipment usage or want to share your latest discovery?
mlc85 (original poster)

#11: Post by mlc85 (original poster) »

Thanks a lot for the help, I have one decent shot now: a 20 second pull versus a 5 second, great improvement! However to get this, I'm basically at the 0 point on my grinder, and I hear a medium sized "clank" noise as i'm grinding. Is this safe?

The grinder is pretty new, i bought it new in December 2007, so only about 9 months old. It has run about 100 pounds of coffee, and I read that after 75 pounds, the burrs need replacement so that may be something I need to look into.

My old machine never had to tamp and a pressurized PF, so I'm sure my technique needs practice. I just am wondering if technique is the only answer as a 5 second shot seems to happen regardless of WDT, tamping pressure, amount of dose etc. Then again I've only had the machine for two days.

The roast is somewhere in the medium-light roast range.
When I'm dosing, I fill to the top of the basket, level it off at the top of the basket, and tamp down. I sometimes get pressure from the grouphead, so it may be too much coffee. I've experimented with a little less, but the shot pulls faster with less coffee.

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Marshall

#12: Post by Marshall »

mlc85 wrote:The grinder is pretty new, i bought it new in December 2007, so only about 9 months old. It has run about 100 pounds of coffee, and I read that after 75 pounds, the burrs need replacement so that may be something I need to look into.
The Internet is full of nonsense like that. For some reason espresso attracts anal/retentive types who like to invent new rules, tests and rituals. Pay no attention. Your burrs should last at least a couple of years.
mlc85 wrote:My old machine never had to tamp and a pressurized PF, so I'm sure my technique needs practice. I just am wondering if technique is the only answer as a 5 second shot seems to happen regardless of WDT, tamping pressure, amount of dose etc. Then again I've only had the machine for two days.
Without trying to be rude, you probably have no technique at all. With your previous setup you had no reason to develop one. Here's a suggestion. Take yourself over to Kean Coffee in Newport Beach during a slow hour (mid-afternoon?). They have good baristas, and the owner is a legendary artisan roaster (Martin Diedrich). Tell them you're a newbie desperate for advice and ask them if they can show you a thing or two. They will probably be flattered and help you. Of course, be sure to buy some of their coffee to take home.
Marshall
Los Angeles

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Randy G.

#13: Post by Randy G. »

Without being there to hear the sound that the grinder is making it is difficult to tell you what to think about it. One man's whrrirr is another man's clank. One Click on Rocky is about 3 to four seconds or so in pull time, all other things being equal, so you are very close.

There is no accurate way to judge a burrset's life by pounds. For example, if you are getting a lot of Kenyan green and home roasting, eventually you will be grinding some concrete, and that definitely shortens the life of burrs. Do you plan on upgrading your grinder in the near future? if not, I suggest just getting a new set of burrs and seeing if that makes a difference... if you are concerned. AND.. if you are going to replace the burrs, go ahead and grind one click finer. What could happen? The burrs suffer more wear? On the other thand, depending on where you got it, you may find you can get warranty service. Maybe they can listen over a good phone...? Here's another scenario- you plan on upgrading, so get a new grinder, and in the same purchase order a new burrset for Rocky, and sell it with "new burrs included." Just spitballing here.

I have been making espresso at home, almost daily, for just short of 8 years. I am just now at he point that I can say, with marked assuredness, that I am finally at a point that I can produce good to excellent espresso, shot after shot, day in and day out. How... Well, it is a combination of factors. The PID-Silvia/Rocky is a good setup, but the margin of error is very narrow. I got to the point that I was consistent, but that meant a very nice to OK first shot and a second that was never quite up to par with the first.

Then I replaced Silvia with the VBM DS and things improved (additionally with the help of Eric's thermometer adapter which deserves more attention here- what a great service and what a great tool!), but I was still searching for dependability in my product. Even the worst shots from that were on par with about the best that Silvia produced, but consistency was lacking. Finally, Rocky left home and was replaced with the Kony. WOW! That did it. I was able to tune my technique to a fine level because the grinder was producing a consistent grind so that I could dose consistently and distribute consistently, and suddenly tamping was not as important. I give one soft tamp, one good hard one, then a few fast pull outs to create a partial vacuum to suck in the loose bits along the edges, and then pull the shot. I am to the pint now that I actually grind a little bit more coarse as the coffee ages over the seven to ten days or so that it lasts for each roasted batch. I can taste the difference now more succinctly each day because all other factors and processes are so well under control.

So, keeping in mind that I do not sell anything and do not benefit from the sales of anything, you will not regret the purchase of a quality grinder. The Rocky is a very good grinder, but it lacks the precision found at the professional end of things. And, YES, it makes a difference.

There was a run of Rocky's that seemed to have an alignment problem, so it is possible that yours might fall into that group, but before you panic, I HIGHLY suggest inviting some coffee folks over for a BBQ or beer and movie night, and let them have a go at your setup.

Please, read my #12 in the "How To" section of my website. It was written with folks like you in mind.
http://www.EspressoMyEspresso.com
It has a huge amount of easy-to-understand information that WILL improve your technique.
When I'm dosing, I fill to the top of the basket, level it off at the top of the basket, and tamp down. I sometimes get pressure from the grouphead, so it may be too much coffee. I've experimented with a little less, but the shot pulls faster with less coffee.
I GUARANTEE that you are using TOO MUCH COFFEE!!!!! You are fracturing the puck when you lock it into the brewhead and it is causing channeling and fast pours!!!!!

I missed a step in my previous directions... D---! :evil: at myself!

I will edit here with more detail...:

VBM (and other E-61) DOSE and TAMP PROCEDURE

1 - as the grinding is taking place, continuously flick the doser lever until the basket is overfilled. There should be very little coffee in the doser at any time during this process. Flick faster than the grinder can supply coffee. This will help break up any clumps of coffee and will give better distribution. it also helps create a slightly more fluffy grind that will tamp better. Move the portafilter around just a bit during this process to try to keep the coffee as level as possible, but don't shake, tap, or knock the portafilter.

Those with doseless grinders will have to deal with how their grinders spit out the coffee.

1b - if there is ANY sign of clumping, apply the WDT.

2 - tap the side of the portafilter GENTLY to settle the grounds just a bit to assure an even distribution. Use a light, plastic tool like the handle of a plastic coffee measure. This is to close any large air pockets in the coffee. You may even see one part of the coffee settle more than other areas. But TAP LIGHTLY, and only once!

3 - level off across the top of the basket with a straight edge. do so in little increments so that you are not pushing a large mass of coffee across the basket as do so without compacting the coffee that is left in the basket.

4- [the part I forgot]- to achieve the proper amount of coffee in the basket, SLIGHTLY bend your little finger and drag it gently across the top of the coffee to "scrape" some off into the doser. How much to remove depends on a lot of factors, but you will test this at the end.. You could weight the coffee to accuracy of tenths of a gram, but this works quite well without the hassle of using a scale.

5 -the dragging of your finger across he coffee disrupted the top of the coffee into a somewhat uneven surface, so now is the time to repeatedly, but gently, tap the portafilter straight down to further settle the coffee and even out the distribution. In this step you should NOT see ANY separation of the coffee from the sides of the basket. The coffee will drop in height, but that is all you want to see happen. The coffee should be somewhat level at this point if all the above steps have gone well.

6 - tamp lightly- maybe one or two pounds. If you have a heavy stainless steel tamper then just use the weight of the tamper and maybe one light finger. Remove it and examine the top of the coffee, it should be flat, level, and free from visible voids and of an even texture. This simply verifies that all the above went well. Now tamp again using a goodly amount of force. As much as 50 pounds isn't going to change much of anything to be concerned with.

7 - remove the tamper quickly and retamp lightly. Repeat this a few times. The partial vacuum created when removing the tamper will 'suck' in much of the loose coffee along the edges. Whatever does not get removed will be of no concern.

8 - OPTIONAL LEARNING STEP: Lock the portafilter into the group, then remove it. Do this gently without banging or knocking the portafilter. There should be NO MARKS on the coffee at all. it should not be disturbed at all. This verifies that you removed sufficient amount of coffee in step #4 above.

That should help you on the road to improving your technique.
www.EspressoMyEspresso.com
* 21st Anniversary 2000-2021 *

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blowery

#14: Post by blowery »

One other thing that may or may not help with your Rocky: try applying a few wraps of teflon tape to the threads that hold the burr assembly in place. It made a world of difference for me and helped to align the two burr sets. Before I added the tape, they would touch at one spot and it sounded like a rhythmic ch-ch-ch. After the tape, they seem to touch over a much wider range and it's more of a shhhhh sound. Either way, with espresso grinds, it's very important for those burrs to be aligned properly and the tape really helped me. I think there's a mention of it in more detail in one of the FAQs or favorites on this site.

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cafeIKE
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#15: Post by cafeIKE »

Feel free to skip steps 1-8 above. It's not gospel.

Put enough coffee in the basket so that when given a gentle side to side shake, it's more or less level with the top. Tamp it down with a LEVEL tamp, upwards from 5 pounds. The coffee should be somewhere around the clip ridge or a little higher.

What does the coffee feel like?

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Randy G.

#16: Post by Randy G. »

cafeIKE wrote:Feel free to skip steps 1-8 above. It's not gospel.
But it works, it's easy, and it's very repeatable.
Put enough coffee in the basket so that when given a gentle side to side shake, it's more or less level with the top. Tamp it down with a LEVEL tamp, upwards from 5 pounds. The coffee should be somewhere around the clip ridge or a little higher.
The problem is that Rocky (at least my Rocky) seemed to create a denser grind (less fluffy) than my Kony and other such grinders, and if you just fill, level, and tamp, you end up with too much coffee n the PF and it hits the screen and fractures the puck.
What does the coffee feel like?
What does it FEEL LIKE!? :roll:

You tell him to ignore my process, out of hand, just like that, and then ask him to FEEL HIS COFFEE!?

The OP seemingly does not have the experience to be able to accurately judge by feel, and with one click on Rocky being about .001" difference in burr distance, two or even three clicks would not be easily discernible by most beginning home baristas. If we try to refine his technique to the point that he can repeatedly create a structurally sound tamped basket-full of coffee, we can then eliminate a very likely cause of his difficulties and then be able to accurately judge whether it is the grinder causing the problems. THAT was the intent of my steps to ensure that he is building a sound set of procedures, now and for the future. Coming from using an enhanced portafilter for so long he needs to start somewhere.

The process as I described it is not gospel, but it sure makes a fine espresso, day in and day out, it is easy to do, takes no special tools, is easy to teach, it's quick, and can be done fairly accurately time after time...

ya... just ignore it.
www.EspressoMyEspresso.com
* 21st Anniversary 2000-2021 *

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cafeIKE
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#17: Post by cafeIKE »

Randy G. wrote:The process as I described it is not gospel, but it sure makes a fine espresso, day in and day out, it is easy to do, takes no special tools...
No special tools :?: Straight edge, plastic tapper, calibrated finger bend :roll:
Randy G. wrote:The process as I described it is not gospel, but it sure makes a fine espresso, day in and day out...easy to teach, it's quick, and can be done fairly accurately time after time...
Ditto :wink:

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HB
Admin

#18: Post by HB »

Keep it up boys and you'll both be in timeout!

Seriously, I alternate between super OCD and just going with the flow. Both work and have their place. For example, my Stockfleths Move for Dummies is way over the top. But combined with the WDT, it's a foolproof combination that any newbie can master in 20 minutes. That said, I would not recommend such obsessive attention to detail long term, it will suck the pleasure out of the process.

For the record, I frequently weigh the coffee dose to eliminate shot-to-shot variation. It's a habit from testing equipment I skip on Fridays at Counter Culture's espresso lab. I cannot remember the last time I employed the WDT.
Dan Kehn

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HB
Admin

#19: Post by HB »

Randy G. wrote:The partial vacuum created when removing the tamper will 'suck' in much of the loose coffee along the edges. Whatever does not get removed will be of no concern.
Sorry, I can't ignore this one... A partial vacuum created when removing a tamper?!? That's even too over the top for me. :lol:
Dan Kehn

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cannonfodder
Team HB

#20: Post by cannonfodder »

It is all getting a bit to over the top. We are making coffee, not launching rockets.

I would second Marshall's suggestion. If you have a good café nearby (and it sounds like you do) go by and see if the barista will show you how he (or she) does it. I use to love going to a good café and just sitting at the bar and watching the barista work. You would be surprised at how much you learn just being observant. I doubt you will see them going through any espresso voodoo, just grind, dose, tamp and pull, but the trick is in the consistency at which they do it.
Dave Stephens