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BNZ MD74 owners - new burrs

MOQMOQ
edited January 1970 in Grinders
Hey fellow MD74 owners

It's been years since I bought my grinder and it's been performing magnificently until very recently.

I started to find our beans from different sources starting to taste quite wrong - flat, boring, awkward mouthfeel. The wife suggested the shots were more like cafe coffee, which has to be one of the ultimate insults. It was her experience on the machine too, so she wasn't having a go at me.

These past two weeks I really struggled with a SO bean that we are very familiar with. Changed grind, dose, basket, temperature, tamp pressure, and none of these yielded anything like what we were used to. So I contacted the roaster who immediate queried whether the burrs were worn out, saying he finds that once a burr set hits 700kg they basically fall off a cliff in performance.

Our MD74 sits at home and we put through about 30kg a year, but did come from a cafe, so I don't have any clue as to how old the burrs were. I had a spare set of burrs and this arvo I swapped them over. The spares did feel much keener on their edges so my roaster's suspicions will probably be proved right in the morning after a few shots to dial the new ones in.

I've read a long thread on CS where other owners found it hard to get the same cutting performance from replacement burrs since they were machined differently, that BNZ Italy are difficult to communicate with, and the AU distributor sells something that's not identical to the originals.

So, the questions ...

Have any MD74 owners replaced their burrs, if so when?
Were the burrs identical to the original parts?
If different did the grinding performance match the originals?
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Comments

  • Koffee_KosmoKoffee_Kosmo
    I am fairly certain that the BNZ factory themselves don't sell the original burrs anymore that were fitted to the older made grinders They have switched to different burrs I actually have a spare set and Im sure they are the newer style - and the current set fitted to my BNZ are the newer variety Having said that I will state that the grind quality is equal but the speed is slower buy a couple of seconds Now a little advice I clean my burrs after 5 kg of beans or about once a month Remove the top burr and wash with detergent and water then leave to dry Then get a chopstick and sharpen one end Use a vacuum cleaner and while scraping away old grinds in the lower burr chamber, vacuum them away until clean I will almost guarantee you that will make the coffee taste better And the grinder grinds better KK
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  • MOQMOQ
    Thanks for your input KK, very much appreciated. It sounds like new burrs for machines of this calibre last between 700-1000kg, and since we only manage about 30kg a year, I doubt if I will need to replace them in any hurry. So long as the cup quality has not changed, that's the most important part. Today I grabbed 8kg of old beans from a roaster and just finished putting them through it to break-in the burrs. Hope to collect more in a few days to put through about 20kg. One said 20kg should be close, the other said usually 20 but could take 50 (his experience on their Roburs). Thanks for the tips about regular cleaning, I do similar but not as often. I'll schedule it as a monthly task. The roaster I visited today recommended I use those grinder tablets to clean it regularly too. He did back-to-back comparison between shots and was surprised at how much better the tablets made the coffee. His explanation was removal of rancid oils. I'll get some to try out but it's time to pull out the vacuum cleaner after today's session. Our early impressions with the new burrs is that the results are definitely better. What I was very surprised about was the huge lift in aroma during grinding - not intensity but much more clearly defined notes coming from beans I thought had "passed it". And here I was thinking my roasters had gone astray with their consistency - all along it was my ignorance of my grinder's condition ...  :doh:
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  • Koffee_KosmoKoffee_Kosmo
    Hmm - I may be getting to that time of burr change myself as I think I am pretty close to 1000 kg However we can both agree that the MD74 is a very good grinder and we are lucky to use one KK
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  • FreshCoffee2FreshCoffee2
    Can I just say one thing? If the manufacturer changes th spec of their grinder in any way, shape or form, its usually because they are trying to improve something. Ergo if they changed the design of the burrs//////.......ditto. I dont believe you should have any fear of changing from an older spec original design burr, to a newer type. Dont forget that the psychology in all this indicates that atleast 50% of comments from people in forums that reckon a grinder's performance is different or worse after changing to different/later spec/design burrs, is likely to be in the mind rather than on the palate because they just dont like or are suspicious of, the change in design. Of the other 50%, 50% of that will be from people that are not "qualified" (in terms of their capability) to comment. So perhaps only a quarter of the total comments in forum threads will carry any real weight in a discussion. Which 25% of all comments is that? If it were me (given enough real world expereince in this field), I would fit the new design burrs and carry on, making a mental note that any differences I think I can detect are simply from changing from a worn out set of burrs, to new ones.  No one can remember what the old type were like when new, in terms of comparing to the new type just fitted. A one on one comparison of old type NEW burrs and new type NEW burrs CANT be made, ie any meaningful observation is not possible. The only meaningul comparison to be made is.....worn out burrs VS new fitment burrs, and the only answer can be that the new burrs are...better. There is no other answer, because the worn burrs are RS, no matter the design. Hope you are enjoying the new lease of life the new burrs have given your grinder, and I hope that helps. And yes...I lied...here is one other observation.  If someone in a retail end forum has observed BNZ to be "difficult" to communicate with, it will be because they may not wish to, or just can't, communicate with one off retail clients. They have agents and importers, who onsell to retailers, who onsell to end users. If an end user wishes to know something, anything, the usual accepted modus operandi is to take it back through the line and in any case, the manufacturer's representative in this country is the importer. If you were having trouble fitting a new screen to your iphone, would it be acceptable practice (or even considered sane) to try and call Steve Jobs (or whoever has replaced him) at apple inc in the US to talk about it? If a retail end client who in many instances in forum land probably didnt even buy the equiment new or from the manufacturer or any of its agents, finds a manufacturer difficult to communicate with,  is this really *the problem*? Hope this helps to put some perspective on some discussions and comments out there in internet forum land  :)
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  • MOQMOQ
    Thanks FC - Yes, new burrs are better than worn out burrs. That was immediately apparent the first session. My "new" old-style burrs seem to be settling in well, the throughput appears to have increased slightly after dumping 8kg though and I hope to collect a load of stale beans from a local roaster today to bump the total to 20+. Eventually  I will order a new set of burrs and whatever comes I'm sure they will work perfectly well. My comments relating to the Manufacturer were from a face-to-face discussion I had with the importer, not just comments from that thread. I try to avoid regurgitating what's said of forums without evaluation of the content, for the exact reasons you cite, and it's mainly why I don't spend a lot of time on them. However I think the comparison between a niche product like the BNZ and mass-market products like an iPhone is a stretch. It's been my experience when dealing with niche products I've bought and received zero joy from the retailer/local distro that going up the chain yields results. For whatever reason Aussies don't like to voice their concerns directly but are happy to moan endlessly to others. I don't know why it's endemic in our culture to just cop it sweet and leave businesses in the dark; even as a multi-gen Aussie I find that weird. I find that people almost always welcome polite and constructive comment whether the feedback is good or bad. It's all in how you phrase it! That said, I always start problem resolution efforts with the vendor first. If after a few contact efforts it appears they are indifferent or useless, it's time to move on. KK - totally agree about being very fortunate to own this grinder.
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  • FreshCoffee2FreshCoffee2
    I have absolutely no connection to BNZ and don't know them (the manufacturer) at all, however I am in agreement they put out a very good grinder. Note I reckon they would be very very interested to read your comment about what their importer said.... but whether you wish to modify your post accordingly I don't know, and as I don't know them at all I won't be drawing their attention to it. Up to you  :) As a sponsor here I am allowed to mention that my people have spent a lot of time looking for a replacement brand grinder for the one we previously imported and supported and built their name over a number of years.....but who let us down badly for our trouble.... and we settled on Fiorenzato mainly because, they are one of very few that can offer a good alternative to the very large high output mazzer grinders (we don't do mazzer unless *forced* to by brand junkie clients).
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  • MOQMOQ
    From what I gather, it'd be a moot point. Apparently they're totally dismissive of any suggestions to slightly alter the design or manufacturing process which could yield significant improvements (and enhance saleability). I'm not talking about electronic dosing, but useful mechanical changes. Doesn't matter to me, it lets me exercise some re-engineering skills!
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  • FreshCoffee2FreshCoffee2
    Hi MOQ. I thought about this long and hard and not trying to be difficut but......I'd like to make a couple more observations. 2 declarations up front first: a) I dont know BNZ the manufacturer, and b) I am not familiar with the CS BNZ thread as I never go there, not even to read.... That said, and therefore only in direct reply to some comments from above: I dont understand how BNZ is a "niche product". It's a coffee grinder intended by the manufacturer, for commercial use in coffee bars (cafes). If the reference in the post above means they wont listen to anyone trying to suggest they somehow "improve their product", I suspect (given the reference to a CS thread) it would be for the benefit of home use forum users for their 2 to 4 cups a day, and that is not what the product is intended for. So....I do imagine they wouldnt listen, but that shouldnt be held against them under the circumstances :)
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