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RoyH

Single dosing with Robur

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@RoyH

I still find your claims very hard to grasp. The only way to really substantiate them, would be a total strip down including the grinds in the case and around the motor, so that you have a virgin grinder, then start experimenting. I would be more than just pleasantly surprised if the first few shots gave you the results you say that you are getting now. Of course, that is a lot of effort and I doubt that you are going to do it, but hey ho!

 

Thanks dfk41. I’m extremely happy with the shots I’m consistently pulling so will have zero need to do that, but thanks for the suggestion anyway.

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Not sure- seems like a waste of time and money to me, but others are convinced retention is such a big issue that they may want to prove it via a taste test?

 

I think dose consistency is more of a practical problem, in that you want the least faff in dosing consistently. If your grinder doesn't let you dose consistently enough to make consistent shots then that could be a taste problem...but being in control, it's up to the barista to be on top of that.

 

Retention probably a bigger issue in day to day, home use & grinds sitting in the grinder for hours/overnight etc. & changing beans shot to shot.


“Coffee evokes the most insane reactions in people”, Rene Redzepi.

 

https://markwjburness.wordpress.com/

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Would love to do a blind taste test and see if the difference was actually discernible between 0.01grams retention and 0.2 grams (or 0.9%) retention.

 

You are welcome to do it, but I can't possibly understand why you would want to. 0.01g retention is a figure I have never even seen claimed, where on earth did you see 0.01g retention claimed?


ACS Vesuvius DBPP, Izzo Duetto DB, Minima DB, Lelit Bianca Prototype DB (paddle flow control) BTC Machines: Roasters: Amazon Dalian 1kg Drum Roaster, other failed roasters: Grinders: Ceado E92, Niche US and UK: 145kg assorted greens: My reviews at https://coffeeequipmentreviews.wordpress.com/

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You are welcome to do it, but I can't possibly understand why you would want to. 0.01g retention is a figure I have never even seen claimed, where on earth did you see 0.01g retention claimed?

 

I saw it in Hubert McNumpty’s 2003 thesis on the matter.

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I saw it in Hubert McNumpty’s 2003 thesis on the matter.

 

I charitably assumed you were trying to have a constructive discussion...obviously not.

 

Gents- I’ve used many grinders over the years. I’ve used Roburs in the past with the static screen still in place, and purging between shots, and fully agree 100 grams (or even 200 grams) could easily be wasted dialling one in. I now have the auto-fill flap and switch gone, static screen gone, and sweep out the chute each time, several times with a small paint brush and bumps of the on switch between sweeps. I can see right up the chute into the burr chamber and do so each shot, so I can confirm there are NIL grounds left in the chute. There may be some grounds still inside the burr chamber, acknowledged, however judging by shot consistency and taste (changing beans types often between shots) I believe any mixing of old and new is negligible.

 

PS- my machine is a MyWay Pompei so I’m not making newbie errors

 

It appears you have nothing to learn, but knowledge to impart, perhaps you should have led with your experience and what you are doing that's special with your Robur so everyone else could benefit...instead of asking a question.


ACS Vesuvius DBPP, Izzo Duetto DB, Minima DB, Lelit Bianca Prototype DB (paddle flow control) BTC Machines: Roasters: Amazon Dalian 1kg Drum Roaster, other failed roasters: Grinders: Ceado E92, Niche US and UK: 145kg assorted greens: My reviews at https://coffeeequipmentreviews.wordpress.com/

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I would be more than just pleasantly surprised if the first few shots gave you the results you say that you are getting now.

 

1kg in, 0.5g in PF.

 

I've had about 140g out of a Robur on a full strip down before.


'it's all about the microbubbubbles'

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1kg in, 0.5g in PF.

 

I've had about 140g out of a Robur on a full strip down before.

 

Pearls before swine I am afraid.....trouble is with having a bit of knowledge sometimes stops you from taking anything else on board

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I charitably assumed you were trying to have a constructive discussion...obviously not.

 

 

 

It appears you have nothing to learn, but knowledge to impart, perhaps you should have led with your experience and what you are doing that's special with your Robur so everyone else could benefit...instead of asking a question.

 

 

DavecUK ....... not so sure you are interested in a constructive discussion.....I think you are more interested in arguing over minutia which means nothing in the cup

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DavecUK ....... not so sure you are interested in a constructive discussion.....I think you are more interested in arguing over minutia which means nothing in the cup

 

We are not arguing about the cup.....we are querying your claims to 0.1 grams retention......perhaps you could explain to us exactly what your routine is to get to this figure? If it is really true and not too much faff, then I would be interested in trying one....I had a Ceado E92 and the routine you had to follow to get very very low retention included running the burrs for 2 x 30 seconds whilst puffing air through. Other than the point of delivery ie doser v on demand they are similar

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DavecUK ....... not so sure you are interested in a constructive discussion.....I think you are more interested in arguing over minutia which means nothing in the cup

 

Is there some sub-text here that isn't obvious to the rest of us?

 

You seem to be saying that you are happy with the dose consistency of your grinder? If so, why worry about what other people feel is appropriate & be confrontational about it?


“Coffee evokes the most insane reactions in people”, Rene Redzepi.

 

https://markwjburness.wordpress.com/

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I will bring back this old topic to confirm that single dosing and with the help of a teaspoon’s handle and 2 starts of the grinder I get 0 retention. 3 months in, I took the burrs out and cleaned the chute and i get 0.1-0.2 tops of retention. Brilliant grinder for home use at a fraction of the Monolith and the likes.

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3 hours ago, webdoc said:

I will bring back this old topic to confirm that single dosing and with the help of a teaspoon’s handle and 2 starts of the grinder I get 0 retention. 3 months in, I took the burrs out and cleaned the chute and i get 0.1-0.2 tops of retention. Brilliant grinder for home use at a fraction of the Monolith and the likes.

There is a difference between retention and exchange.

I've never seen a robur get zero exchange and retention before, perhaps I'm wrong and you have solved the age old problems others had. 

@coffeechap did you ever achieve it. 

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24 minutes ago, Mrboots2u said:

There is a difference between retention and exchange.

I've never seen a robur get zero exchange and retention before, perhaps I'm wrong and you have solved the age old problems others had. 

@coffeechap did you ever achieve it. 

I guess with single dosing it and polishing the internals in theory it is possible. I gave up trying and don’t really see the point of modifying massive commercial grinders in light of the shake shake niche. Unless of course you get a rogue/kony for silly money.

 

would be interested in seeing any videos of a robust single dosing from completely clean, just to see how much comes out on the first grind @webdoc

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AKA Toffee chips

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"0.2g tops" doesn't sound realistic. There's probably noise in your scales' readings if that is all you are seeing. Over enough doses the variance in whole bean dose will be about 0.1g.

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“Coffee evokes the most insane reactions in people”, Rene Redzepi.

 

https://markwjburness.wordpress.com/

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Not sure if this helps but In day to use I get 0.1g retention or less on a moded Major after polishing the grind chamber and lower burr carrier, the Mazzer 83mm burrs have a gap on their inner edge which will hold grinds until full, after that 0.1g often none, yes after each grind a pastry brush is deployed in the funnel for a few seconds but it only cost £250 and the motor will never break. Ive got an idea for filling the gap under the inner edge of the burrs with some food grade ptfe gasket sheet.


keep calm and grind flat

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Not sure if this helps but In day to use I get 0.1g retention or less on a moded Major after polishing the grind chamber and lower burr carrier, the Mazzer 83mm burrs have a gap on their inner edge which will hold grinds until full, after that 0.1g often none, yes after each grind a pastry brush is deployed in the funnel for a few seconds but it only cost £250 and the motor will never break. Ive got an idea for filling the gap under the inner edge of the burrs with some food grade ptfe gasket sheet.
A bead of silicon sealant could also work.

Laissez les bons temps rouler

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Posted (edited)

 

10 hours ago, coffeechap said:

I guess with single dosing it and polishing the internals in theory it is possible. I gave up trying and don’t really see the point of modifying massive commercial grinders in light of the shake shake niche. Unless of course you get a rogue/kony for silly money.

 

would be interested in seeing any videos of a robust single dosing from completely clean, just to see how much comes out on the first grind @webdoc

I will do that later, for now I tend to agree, I just started comparing Robur to the Niche and strangely, taste-wise, the Niche came out on top today, lighty roasted Ethiopia from the North.

 

8 hours ago, jimbojohn55 said:

Not sure if this helps but In day to use I get 0.1g retention or less on a moded Major after polishing the grind chamber and lower burr carrier, the Mazzer 83mm burrs have a gap on their inner edge which will hold grinds until full, after that 0.1g often none, yes after each grind a pastry brush is deployed in the funnel for a few seconds but it only cost £250 and the motor will never break. Ive got an idea for filling the gap under the inner edge of the burrs with some food grade ptfe gasket sheet.

Exactly, my teaspoon handle does just that, the brush stuffs some coffee inside. I haven't even polished the chute. For me after a few months of using it, that gap has barely retained any grinds. I am sure used in a comercial enviormennt will hold plenty over time, I just don't think it will for home use.

 

PS: having done that a month ago i was wrong, it was 0.9g.

https://imgur.com/a/xRIAgKk

 

Edited by webdoc

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18 minutes ago, webdoc said:

 

 

Yet it is.

I don't doubt that's what you are reading, but you're only seeing that because your scales are not up to the job, a bit like measuring cm with an inch ruler.

I took 20 readings with 0.1g resolution scales with my Niche & saw no difference, because my 0.1g resolution scales don't react to every 0.1g change in weight and aren't precise to 0.0g.

In reality with 20 readings with 0.01g scales and I see +/-0.18g stddev, or about +/-0.4g for 95/100 reads.

I'm sure your dose consistency is very good & small enough not to worry about, but I doubt it is half that of Niche, Monolith & other similar performing (in terms of consistency) grinders.


“Coffee evokes the most insane reactions in people”, Rene Redzepi.

 

https://markwjburness.wordpress.com/

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Posted (edited)

I just thoroughly purged the grinder with an "enema bulb" (Borat's accent) to take all the remaining coffee out as I assembled the grinder a few days ago, so it was clean. I also use knockoffs LW tumbler in two colors and there is a 3g difference between them, thats why it shows less coffee. I would have done it better but I only had one hand free in the process. I could have swept less, but I am a bit obsessive 😀

It took 0.3ish grams on the first run, I say it's pretty great.

Here is the link to the video, it was too large to attach it here.

Video

Edited by webdoc

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Posted (edited)

So you put 19.1g in and got 19.1 g out, is it the same coffee that you put in. Again there is a difference between rentention and exchange. 

When a coffee shop ran a Robur and changed grind they had to purge quite  bit to get to the correct fresh grind . 

I am a little sceptical although willing to be levied wring for sure that all this has been solved by a teaspoon

What's filling the gaps up( coffee wise )  and stays there and then what isn't coming out in a shot ( so 19g in 17g out along with 2 g from eh last shot )  but is being moved along by the next shot.

Edited by Mrboots2u
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I write a blog, it's nothing to do with coffee ...

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Having a hopper fills the chamber and burrs and chute, by the time you get the new grind out I could see it taking 100g.

Single dosing is coffee in - coffee out with 0 retention most of the time. The exchange you are saying involves 0.2g tops because most of the stale coffee (of the 0.9g recorded by me )is oily residue that is sticking inside the chamber, so new coffee in will only graze that. It's silly talk, I just showed you it has near - retention/exchange/whatever you want to call it, single dosed. It is a wonderful grinder very well suited for single dosing, with a few small caveats.

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Posted (edited)
On 13/07/2019 at 18:36, coffeechap said:

would be interested in seeing any videos of a robust single dosing from completely clean, just to see how much comes out on the first grind @webdoc

Hey guys,

I normally read the forum quietly as a lurker. :P But wanted to chime in as I had gone through the exact process/exercise and wanted to share that.

It is definitely possible to achieve ~0.2g retention after a full strip-down cleaning, with a stock Robur E.  ~0.1g retention/exchange during normal use is not out of realm either. No voodoo, no polishing needed. :p 

https://www.home-barista.com/grinders/thought-on-single-dosing-mazzer-robur-e-after-few-months-t42401.html

There's a video at the end for a completely cleaned Robur. 15.0g in 14.8 g out. You could argue the scale resolution is limited to +/- 0.1g so maybe it was 0.3g. Still pretty darn good value if you can find one for a song, and they're built like a tank. Though they can take up some space if that's a concern. 

Certainly not as easy to use (more faff) as the Niche, but hey it is possible/workable. ;p 

Edited by samuellaw178
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I'm actually gonna go and say that yes you can deep clean a Robur and put 20g in and get +/-0.5g out. Once, in my experience.

 

I have a brand new Robur E (1year old) and once put 20g in, then 19.6g out. Then another 20g in and 15g out. Then another 20g in and 11g out. Then decided to just dump a kg in a hopper on it and run 200g to dial in with.

 

 

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'it's all about the microbubbubbles'

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I'm actually gonna go and say that yes you can deep clean a Robur and put 20g in and get +/-0.5g out. Once, in my experience.
 
I have a brand new Robur E (1year old) and once put 20g in, then 19.6g out. Then another 20g in and 15g out. Then another 20g in and 11g out. Then decided to just dump a kg in a hopper on it and run 200g to dial in with.
 
 
Ha, yes! Same with the E92. Sometimes the exact same, sometimes 5g more, sometimes 10g less. Complete lottery. But put some beans in the hopper, dial it in properly and it kicks my Niche out of the park. But totally wasteful and impractical in the home.



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I'm actually gonna go and say that yes you can deep clean a Robur and put 20g in and get +/-0.5g out. Once, in my experience.
 

 

^^ this.

 

I loved my Robert [edit: that really was the Robur’s name.]. I polished the chute and it had fins fitted to the sweeper. From completely clean it would short change you a small amount but that amount would build up. After a weeks use the chamber would be claggy as all hell.

 

‘Exchange’ is a real issue with this Bad Boy. It makes dialing in a shot very expensive!

 

Also, I went crazy with a refractometer around the same time and I found that i achieved higher EY using a column of beans with a 1kg weight on top rather than single dosing. But love it as I did, the retention was huge. Ceado E92 achieves the same performance and it single doses with acceptable (to me) retention

 


Espresso: Ceado E92 (modified for single dose); Vesuvius; VST baskets and refractometer.

Other: Aeropress, Sowden and Alessi Moka Pot; Mazzer Robur doser with Auber timer; Mazzer Mini E; Expobar Leva Dual Boiler

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