Who can afford to keep a pile of coins lying around for scale calibration?
Just use the coins to buy a better set of scales!
With no calibrated weight set available a good way to check the accuracy of your scale is using coins. Use ones in as close to mint condition as possible. To see if your scale is varying over time keep the coins you use set off to the side so that you're using the same exact coins every time.
Java "Cali-what?" phile
Toys! I must have new toys!!!
Who can afford to keep a pile of coins lying around for scale calibration?
Just use the coins to buy a better set of scales!
I do have a set of small metric weights.
Checked my $10 scales a few minutes ago, seems they are 0.25% heavy over their range so 18 grams becomes 18.045, think I can live with this margin of error, we ain't weighing diamonds.
A dollar or two pile of coins won't buy you much of a scale upgrade.
Java "Pile 'o what?" phile
Toys! I must have new toys!!!
If anyone is in a capital city and interested it looks like you can rego for a free demo of the Ona OCD...
Australian Barista Champion Hugh Kelly will be travelling around giving demos. Enjoy!
I've just received a Kafetek Conical grinder and it came with a distribution tool designed by Denis Baseric from Kafetek . I already had an OCD V1. Used Denis' version and I prefer it. Very easy to adjust the height, and nicer grip (doesn't slip). If anyone's interested, I can post a picture.
I'm interested in a pic
I do like the ONA tool and recommend it you anyone looking for consistency. It is simply a tool to help improve consistency. Is it necessary? No. Is it helpful in making channelling a thing of the past? Yes.
The ONA tool weighs 410g and the Kafetek one weighs 505g. They both really achieve a well distributed level base, perfect to tamp on. Would I have changed tools if I didn't get one with the Kafetek grinder? No.
I have two ONA tools, one for home and one at the office. One is now surplus.
How do the base designs compare? The OCD is 4 bladed, others I have seen are 3 and the blades do not appear to be as aggressive.
You are correct Artman. I have tried both. With the 3 blade you need to go a little deeper with a small amount of compression to get a good distribution. If you don't go deep enough you end up with cracks which might remain after tamping leading to channelling. I'd love to know how the Pullman chisel compares to these as it has a "V" shaped base
Hugh ran through the design process and showed a few prototypes, explaining why they didn't work as well as the final shape. The most interesting revelation to me was that the OCD is designed to "roll" the coffee over like a wave as it sweeps, meaning the final distribution is as even as possible - which is why the design has fairly shallow angles and large flats on the top surface. More aggressive designs tended to push the coffee down into the basket, rather than sweeping it across, forming compacted areas.
Hugh made the point a few times that the other designs Ona tried (some of which are strikingly similar to other tools on the market) might achieve a nice looking flat surface, but didn't improve distribution; in fact some even made it worse.
Clearly the tool is designed for a commercial environment, and many of the benefits relate to having a repeatable, speedy work flow and the presentation reflected that, but I found it interesting nonetheless.
A couple of slides from the night illustrating the differences between the OCD and other designs.
(apologies for the distortion - had to do quite a bit of tweaking as I was sitting at a pretty obtuse angle to the screen).
Was this a heavy sales pitch Matt? Were you convinced that OCD is "better" than the Chinese clones or Pullman chisel or is the jury still out?
I wonder if the Socratic Coffee guys were there..
Look, I was certainly convinced that Ona have put a lot of time and money into researching the most effective design. I strongly doubt that the direct-from-factory versions have anything like the amount of R&D behind them. Hugh didn't say a lot directly about the Chisel except to identify it as the mystery second distro tool used for the shots that won the vote, and he said something to the effect of "there is no one best tool, they have different effects in the cup and what works for one coffee might not be the best for another."
In reality I think Ona believe they have the best design (I'll add another photo with some of their prototypes and rejects), so perhaps whether it was a sales pitch or not depends on your perspective.
Also to paraphrase, "I'm not saying you have to use a distribution tool to get an excellent shot; for years WBC champions have used manual methods and made outstanding espresso" IOW the emphasis was on cafe work flow and training (he gave an example of a junior barista who went from struggling to keep up and spending 15 seconds on distribution to less than 5, meaning she stressed less and had more time to concentrate on managing dose, tamp and monitoring the extraction).
Which kinda begs the question, if new baristas become reliant on distro tools, what will happen when they get a job in a place that doesn't use them? 🤔
Apparently the second one from the right held heaps of coffee...
Will that barista not be tempted to buy an Ona OCD and bring it with them to work?
Just as a chef or butcher brings their bag of knives to work?
I suspect tapping to settle and even out the the grinds in the PF does most all of the work. However in situations where the barista may not be as confident I suspect this device will help level the field.
Socratic / BH crew have tested and noted their results. Ona have noted their results.
The technique using the OCD is not to settle the grinds at all - the theory being that this causes the fines to move to the bottom of the puck (stratification) and compacts the piled up areas so although the puck looks evenly distributed, it has areas of higher and lower density.
Hugh told another story there - his understudy was roped into a barista comp at the last minute; using the same beans Hugh had been preparing with for months, he went further in the comp. Hugh put the difference down his offsider being the only competitor *not* tapping to settle.
Tapping on the side, or tapping as in collapsing?
I reckon there'd be just as much fine migration tapping on the side of the portafilter as using a distributor - but that's entirely conjecture.
So Magic Matt, what are your feelings about distribution tools after seeing the full presentation?
Ps thanks for the great summary
Did Hugh talk about any results that ONA got in testing of the OCD as far as espresso extraction percentages goes? I haven't actually heard if ONA have done much testing of the OCD in this area, and if they have how widely they've tested the device using different equipment and coffees. The feeling I get is that there is a bit of a consensus forming when you put together all the independent tests, and its sort of along two lines:
1. The OCD, Chisel and similar distribution tools may provide some good assistance in regards to workflow consistency, especially in a very busy cafe setting. This is obviously dependent on the set up of a particular cafe as well as the individual baristas, and the equipment and coffee being used. At the end of the day Sasa Sestic and ONA actually designed the OCD for this very purpose. While I'm sure he knew there would be uptake from dedicated amateur coffee geeks, the target market is a commercial market.
2. The OCD at least, as well as some other distribution tools potentially make very little difference when it comes to results in the cup and extraction percentages. At worst there's the potential for the OCD to dramatically LOWER extraction, and at best it makes it neither more consistent or better than a simple tap and settle. While the experiments that have been done that have garnered these results need to be considered I don't think they should be the sole deciding factor for anyone looking to buy a distribution tool. I think anecdotal evidence is also important and the story Hugh told of a particular junior barista that gained great efficiency and confidence through using an OCD is definitely relevant.
So, I may not have this 100%, but afaicr Hugh made the point that uneven distribution, and to some extent the stratification of the coffee bed caused by tapping prior to tamping, leads to overextraction of some parts of the coffee puck (either through simple faster extraction in areas of lower density, or channelling and other problems caused by stratification). So you have to cut the shot shorter and get lower TDS.
From memory he did say something about their testing revealing the OCD resulting in higher TDS, but also that some coffees might work better with a different approach or tool. He mentioned a few times that the material used for the distribution tool had a noticeable impact on flavour, which I found surprising.
This graph doesn't relate directly to TDS - but does show that the distribution tool used can impact flow rate.
Still waiting for it to arrive (just got a couple of Aus Post notifications so it might be waiting in a parcel locker now).
So I was already curious enough to throw down a hundred bucks to do my own experimentation. I already have a generic 120į/3 "blade" distro tool, which has been interesting to use, so I'm looking forward to doing some back-to-back tests with it, the OCD and some other distro methods. So far, my experience with the generic is that it improves the evenness of the extraction, but doesn't entirely solve channelling and sometimes even seems to make it a little worse (mostly with lighter roasts).
Distribution has been a bit of a journey for me - started using WDT with my Sunbeam 480 years back, have used various manual methods single-dosing with my conical and recently have used a combination of dosing cups and the V-Titan's dosing funnel, all with mixed results but never quite satisfactory... I'm cautiously optimistic that the OCD will be a step in the right direction.
Hugh's presentation certainly gave me some confidence that Ona have done their homework and it's not just an expensive paperweight, as some are fond of saying... 😉 The proof will be in the results; though just today I asked a mate who runs a busy cafe in the CBD about it - he's been using a V1 for almost a year and had only good things to say.
Thanks Matt, will be even more interesting to read your personal comparisons
A friend of mine came around the other day and we did a comparison between the Chinese cheapie and the OCD V2. This is not based on any scientific readings, just gut feeling, observations and taste.
1. Aesthetics .... OCD does look pretty classy but this is purely subjective
2. Build quality ... OCD a clear winner
3. Adustability ... OCD was much easier to lock in and with a scale on the side it was easy to come back to a setting after changing coffee .
4. Distribution ... OCD was more aggressive and left a fluffier surface. Chinese version had to be a little deeper and left a smoother surface. The OCD appeared to have a better distribution (see point 7)
5. Taste .... A draw. Well to our overly mature taste buds
6. Feel ... Chinese version felt more comfortable in my small hands. OCD felt bulky
7. Diameter ... OCD was 58.4mm which was a better fit in VST basket. The other was 58mm and the edges, consequently, didn't seem as well distributed which may lead to chanelling
The OCD is a better product and does a better job at distribution leading to better consistency. Is it worth it? $35 compared to $210 is a no brainer when they both lead to similar tasting coffees. If you're thinking of buying one of these and you have an adequate disposable income then get the OCD but it is very difficult to justify the price difference when they pretty much do the same thing. I still like what these do.
I have not experimented with a V shape tool eg Pullman chisel but i'm sure they're similar.
EDIT ... I forgot to mention this was done on a Rocket V3 PID using 17gms in a 15gm VST basket and dialled in for a double ristretto.
Last edited by barri; 23rd May 2017 at 07:32 PM.
I forgot to mention..... 8. Cleaning ...... Grinds stick to the OCD meaning I have to brush it down after every coffee. Where as the clone just needs a brushing at the end of the day. Not a deal breaker!
Hugh mentioned that some static and sticking is unavoidable; the aggressive shape makes this worse - but it's a balancing act between benefit and minute loss/mess.
Apparently they are now shipping with a branded microfibre cloth. I sit my tamper and distro tools on one of my 'barista cloths' ($2 for three from Bunnings 😉 and give them a tiny spin/twist before use.
Iíve been using four different types, the shot collar, Pullman chisel, OCD v2 and a Chinese knock off, I think, not sure because it came with a grinder I bought.
I have used OCD v1 as well but find V2 better in regards to grip and adjustability.
OCD v1 & 2 grinds stick to it but not much to worry about, just have to clean every so often. I used V2 more until I got a Pullman chisel. With this one no grinds stick to it and I seem to get better pours. One con is it doesnít go as shallow as the OCD V2.
Now the for the shot collar, I saw this and thought this is the one, I thought minimal compression, awesome distribution but no, after spinning it I was left with a big hill in my basket.
I tried raising the bar but that just groomed the top of the coffee. One good thing with this is Iím going to try a few modifications with it. I have an engineering friend that can modify some sort of thin steal fingers or something on it and see how it goes.
I always seem to go back to the Pullman chisel, just have to get my mate to shave a few more mills of it so it can go a little higher.
I couldn't help but notice your jugs (try saying that to a non CS ) they look brilliant and make a very nice change to the usual steel ones that you see.
if you don't mind me asking where did you get them from ?
I managed to grab a OCD v2 from a NSW supplier at $179 which I still see is on sale now. Up until I received the OCD I was using the yogurt pot WDT method with stirring stick with much improved and more consistent results over what I was doing since I got my new machine which was the tap to settle and level off with a dosing tool.
In comparing using the OCD to the WDT two things were immediately improved and that was the reduction in the amount of mess I made with grinds on the counter and a reduction in the time for preparing each shot before locking the PF into the group head. Ultimately I cannot say with absolute certainty that the OCD does a better or worse job in preparing my dose than WDT but it is definitely more consistent and improved over what I had been doing for years up until recently and looks a damn sight better on the counter than a cut off yogurt pot .
I am personally sold on the OCD and cannot see myself reverting to any former methods if not for anything more than the increased speed with which I can make two great latte's each morning before work.
I just received my artisan smith precision cup with distributor so here are my first impressions
1 - item took ages to arrive as it comes from vietnam not sydney
2 - workmanship of the dosing cup is horrible. I bought the brass version which looks like it's sprayed on for colour. welding is sad and overall poor quality
3 - the dosing cup fits the sette grinder but with adjustment of the rubber holders
4 - the leveller does not work! no matter how many turns you make on while over turned on the portafilter, it still produces a one sided mount of coffee
Hey that's not good to learn Boontsien, I did wonder if those systems were worthwhile, guess you have put me to rest on that one
I can hear Ebay calling you !
Keep meaning to reply to the mess factor on OCD v1 as I've not had a look at this thread for awhile.
Wanting to see if you can replicate this...
First there was the v1 grip hack adding the wristband.
Now I've had mess free operation on the v1 after polishing the base of the v1 in a clockwise direction with micro fibre cloth. I'm wondering could this be the "micro fibre rub" mess hack for v1 owners?
For grip I've added a few rubber bands as I didn't have a silicon wristband to hand, works great for grip. I much prefer the low profile of the V1 to my generic tool that uses the same three-piece construction as the V2.
I got a v2 OCD yesterday so I'll give it a week to make a judgement, but my initial pours were very even.
So I have had my OCDv2 since April and thought I would loop back around to provide my thoughts after using it daily since. The distributer is now part of my standard routine, its not a fad.
I have found it does truly make a big difference on the consistency of each shot with very little evidence of channeling and a much more even extraction with a good puck formed after extraction. It certainly take the 'OCD' out of this part of the process IMHO.
A further observation I have is that it helps also in tuning your dose when changing beans by giving visual clues after you sit the OCD on your portafilter and spin it a few times. If you have overdosed you will see a pattern of the OCD in the top of the puck conversely if you have under-dosed the surface of the coffee after spinning the OCT does not appear smooth, a quick check on the scales confirms this.
After having used the OCD for a while now, my tip for a consistent extraction with this tool would be - let your grinder dose your basket, do not tap, do not level, do not dance a little rain dance or whatever little quirk you might like typically to apply. Simply lower the OCD down onto the naturally peaked grounds, seat it on the basket lip and spin 3 or 4 rotations. I tried tapping and leveling and it appeared to me this act tended to introduce more occurrences of channeling and uneven extractions.