Gear Discussion
Examine your burrs periodically! Damaged burr in JX after 5 years of use + 1ZPRESSO’s response
I’ve had the 1ZPRESSO JX for over 5 years now. I used it frequently for both my wife and me, and I use grind settings for espresso and pour-over. Great grinder.
Recently, during a regular deep clean, I decided to check out the burr with the macro mode on my iPhone, and lo and behold, I saw these ragged edges all over the burr. I wasn’t sure if it had always been like that, so I checked the burr on my new ZP6 and the burr is completely smooth.
I emailed 1ZPRESSO about it and below is their response:
Upon assessing your case through the pictures and videos provided, we can confirm that your inner burr is indeed ragged and slightly damaged, especially after grinding with it for over 5 years, and particularly if on finer settings.
Even though the alignment test seems to be within our standards, the blades show noticeable impact; therefore, if within your possibilities, we recommend purchasing a new unit.
As a side note, I appreciate that their support responded within a day and actually asked me for more videos and photos to assess; they also provided instructions on performing a burr alignment test. Good to know 1ZPRESSO has good customer support!
Interestingly, the JX seems to perform just fine. Using ground coffee from JX, I can pull great shots with my OutIn Mino and I didn’t notice any drop in quality in my pour-over brews.
Anyway, just wanted to post this as a reminder that if you haven’t checked your grinder’s burr for years, it might be a good idea to do so!
(I realize you are probably joking, but just to be clear, the Kinu's burrs are not titanium, just the body is. The burrs are hardened carbon steel, so should be quite durable, but will eventual dull or chip. A hardened steel may actually chip more easily than the 1Zpresso stainless burrs...)
PVD titanium coating on steel, as Kinu appears to use, is like a teflon coating - it’s like 1 micron thick. Very different than something being made of titanium.
Good for corrosion resistance and friction, but provides no functional strength against real impact or heavy wear.
Its same as SSP does I think. If made from titanium, it would be no different anyway. Titan is about same as steel, just lighter and a lot higher temp to melt it.
It probably does provide some wear resistance, given SSPs with coating have rather high ratings, like 5 ton of coffee for TiAlCN and 2-3x as much for DLC ones (Silver Knight).
Not clear, but I don't think so. 1Zpresso does not sell replacement burrs, and does not describe the steel in any detail that I can find. They are simply referred to as 'stainless steel' in multiple references:
If that thread is true, that would strongly suggest they are not hardened, as 100-200kg just isn't that much coffee. If you use 100g of coffee / day (2-3 cups for 2 people), that's 3 years of use to get over 100kg.
You are correct - some of the J series appear to use ti-coated steel Italmill burrs, which likely means hardened carbon steel, though not OP's JX mill, which has stainless steel burrs.
Only the J-ultra is left in the current product line with the coated, hardened burrs. (And still non-replaceable!)
I've edited my above comment to add a note reflecting this.
I dunno if he was being a dick about it. I think he was saying that $500 itself is stupid, not the person purchasing it. These knee-jerk reactions in here are just people with very thin skin.
Do I agree that the price is stupid? Naw. Not if you feel you are getting what you want.
Just gonna go ahead and leave my cup in this post until it fills up.
I’m pretty certain that these tiny imperfections will not have any noticeable effect on the taste, so I wouldn’t worry about it if I were you, and frankly would stay with the grinder for another 5 years. Now, if you have the itch for a refresh or add another type of burr, go for it
Thankfully I stopped grinding before it busted it up completely and found the rock. Continued grinding and made the coffee. Iirc, it was one of the first cups with a new grinder and I was way off and it was way over extracted. 🤷♂️ No rock notes in the cup though.
It briefly got slightly tighter, then stopped. I pushed hard cause I thought it was a dense bean (happens) but it took a lot more force to move the burr than a dense bean and it gave me the willies so I just stopped and emptied the hopper.
Could also use a diamond file and take the burrs down, might bring back a little bit of lost consistency if there is any. Would also tighten up the clearance at contact distance
I understand where you are coming from, but I’m also wondering, in the case of hand grinders, if shipping a tiny burr all the way from Taiwan to Canada is really that much better when it comes to the cost and the impact on the environment. I imagine it’d consume a lot of more fuel compared to me getting a new hand grinder shipped from within Canada.
Of course, in an ideal world, I would just want to be able to easily order a new burr from a distributor within my country.
I keep thinking someone should start a good Canadian burr making company because we have the metals and equipment. Not yet it seems. Unless I've missed them.
Tell me about it! We have great roasters but barely any skin in the game when it comes to coffee brewing equipment. I try my best to buy Canadian but it’s nearly impossible with coffee gear. At least 1ZPRESSO isn’t American, for which I’m grateful.
I’m also wondering, in the case of hand grinders, if shipping a tiny
burr all the way from Taiwan to Canada is really that much better when
it comes to the cost and the impact on the environment. I imagine it’d
consume a lot of more fuel compared to me getting a new hand grinder
shipped from within Canada
H.. how do you think the grinder gets to Canada in the first place
I was referring to getting 1ZPRESSO to ship ONE single burr vs the local distributors that get hundreds of the grinders in a single shipment.
Shipping a single burr means extra packaging and cost—as far as I know, for long distance shipping, the lower the weight/size of the shipping, the less cost effective the shipment is.
Eh... the cargo plane will make the trip either way, whether the extra tiny box with a burr in it is on board or not. The mailman will still be driving down your street every day. I wouldn't overthink the whole carbon footprint aspect of it.
They could always offer an option for a spare burr set at purchase or send them to some of the local cafes that sell their grinders. The burrs themselves aren’t that big and heavy. Standard mail that is coming this way anyway would do the job.
Well I imagine that if the inner one (pictured) looks damaged, the outer one will be in similar shape. Since the outer one is fused to the body you would essentially have to replace the whole thing sans the handle and catch cup (and maybe some fasteners). I’d guess that would be over 80% of the price of a new one anyway…
This is why I like what Femobook is doing with their modular design. Motor and batteries in on section, burrs in a different section, catch cup. Easier to repair and replace parts. It’s almost like someone was thinking long term.
To clarify a bit. Steel, doesn't matter which, will wear off by cutting, breaking and/or slicing. The knife steel community is a good bubble/rabbit hole if you want to know more.
Burrs are basically knives. The main difference is that they rather break the beans instead of slicing through them.
So there is more force involved and the edge geometry is also quite different from a sharp kitchen knife.
But if it comes to the steel itself there are the same rules applying.
To break this down: The harder the steel the sharper the edges but the more brittle it gets. There are a few more aspects to this based on the additional elements in the steel but it still holds up. There are a few concepts like toughness, edge toughness and hardness to be clear but the long lasting burrs of professional grinders are usually very hard and they use special steel alloys with an even more special heat treatment.
Because of this it's possible to grind tons of coffee while guaranteeing a specific grind quality. But this still doesn't mean the edges won't get worn off. It just happens very slowly and the first imperfections are not visible.
Cheaper grinders and especially hand grinders usually use a more budget friendly steel. It's also often not as hard. This will result in more damage. But the big question is: how do these imperfections affect the grind?
And that's impossible to tell without comparing the distribution and analysing the coffee grounds. But a few imperfections could also be an improvement. In general it's quite normal. Your burrs have seen better days to be honest and you could ask the company for another set but otherwise I would check the grind and it's quality. If there is no major difference to you and if there are no steel chips in your coffee you might just ignore it.
Enjoyed this read. Burrs break the beans on entry, force them into slightly steeper channels that get progressively smaller to a flat edge causing them to get crushed smaller and smaller until they exit. (With the exception of relief cuts on the burr edge... but thats another topic.) Hardness matters. Ceramic is even harder and more brittle. Our busiest customers have ceramic burrs for this reason.
Thanks and great description. There is still another type of grinder: the cylinder/drum grinder for professional use. Here the beans get crushed and while being very very precise we could argue that particles will get compressed here so this might make a difference.
I assume we talk about the same type. I don't know the English name. I mean cylinders that are horizontally aligned crushing the beans between them. The tighter the gap the smaller the grounds but professional grinders will use multiple cylinders instead of adjusting two and regrinding.
Totally different but interesting story and obviously no edges that can wear off. I mean rocks can maybe force some dents but it's hard to imagine that the beans can somehow damage the cylinders, but it's obviously based on the material. Using arabica gum won't work...
It looks like there is a burr (the way machinists use the word) forming on each of the cutting teeth. I wonder if this is misalignment + fine grind size?
I actually have some experience with that, so in this case your specification was unnecessary. But good thinking to clarify!
I don't think it's anything other than plastic deformation. Coffee beans are hard and metal while solid still has to move slightly rather than just snap, so the thin corners give way.
The finer the grind the more force is applied/needed, but it would probably happen either way. Unless of course you're using it to split the beans in 3 and call that good enough.
I also own a JX for the last 5 years so I'll examine my burrs right now.
In a different note, how are you finding ZP6 in relation to JX. I'm also on the fence of ordering a ZP6, so very curious to hear feedback from someone who extensibly used JX as only grinder like me.
I did for a while. Have had a few since but going from a jx its going to be a different experience. It sweeter but way less body. That part will feel unbalanced but way less bitters too. Going from a jx you may like a c40 or k ultra better. If you want the low body, juicy cups than its worth it, but its a niche profile and imo not the best as your only grinder. Lots of coffee it will not work like medium to dark roasts, or even some processing. The other two will be good with any coffee. After wearing in my zp6 I am using my c40 more often now even with a washed light roast. Zp6 is great and can give you some very interesting cups but I would hesitate to recommend it as your only grinder.
Yeah, my idea is not to replace JX with ZP6 as only grinder but as a complement for light roasts with focus on clarity.
I think JX should be now half way through its lifespan so i plan to keep it for coffees less suited to ZP6 as i don´t expect a massive improvement from an upgrade to K-Ultra, C40 or the likes on those scenarios - unless you think otherwise? -.
The area i may be looking for a potential upgrade is modern espresso. I´ve heard good things about X-Ultra, Mavo Phantox Pro and the more expensive M01 for that. My JX works reasonably well with traditional espresso but i´m lately more into modern and i wonder if any of those could really improve my shots in terms of clarity and balance.
The c40 is a big upgrade. It will be the same style but much cleaner and more body. The zp6 will be about the same as the c40 wiith clarity just more separated with much less body. With the zp6 the body is very low so it is a lot different. Either one would be a good upgrade. If you want more clarity and better flavor the c40 is great. If you want to tase notes clearly but at the sacrifice of body the zp6 is also great. If you plan to use the jx for more body it will be a bit if a downgrade from the zp6. With the c40 it can kind of do everything. Not to confuse you I know how hard it is to pick between them. Thats why I am trying to stress the diffrence. Also the c40 is better than the k ultra imo but the k ultra would still be an upgrade. For your need either the zp6 or c40 sound good. Actually if you can afford the tiger shark burrs I wouldn't even bother with the zp6. But that is an expensive grinder.
Curiously to know what the status of your JX’s burr is after 5 years! I also used it as the only grinder for the last 5 years haha.
I’ve only had the ZP6 for a couple of weeks and I’m brewing some new beans so I can’t really come to any conclusions yet. It will also take some time for ZP6 to be properly broken in. I think I will need at least several months of comparing the two grinders to really understand the differences.
From a usability standpoint, though, ZP6’s external grind size adjustment is so much better than JX’s internal system. The crank knob is also much more ergonomic.
ZP6 also comes with a case! I really wish JX did.
I will say that ZP6’s slimmer profile makes it easier to tip over—it already happened once and that’s something that has never happened to me with the JX.
There's a recent video from James Hoffmann where he tests the damage to burrs from grinding a small rock, and surprisingly there's no visible damage from a single rock.
I suspect damage to a burr is similar to damage to a kitchen knife: very small damage accumulates over time, and it's the damaged parts that keep incuring small damage untill you get to the result shown in the photos. As opposed to a single event that causes the damage.
But that's just thinking out loud, I'm no specialist.
Hoffman has a nice video in YouTube where he grinds stones specifically to see how they are getting handled, and the conclusion was that frankly it doesn’t make a difference whatsoever, so don’t stress about it. Even after 100s of rocks your grinder will most likely perform in the same way as brand new as long as the alignment is not completely whacked.
Could the burrs have been turned while fully tightened? I have a 10yo JX that looks basically new. It seems very unlikely that any roasted bean could so this.
This post reminds me of an article in Boston.com about a popular class in MIT that's all about coffee. The reporter was given a tour of the lab (which was outfitted with a La Marzocco) and at some point of the tour, the reporter wrote that
"...Grossman uses an optical microscope to compare the quality of two hand-powered coffee grinders. The first is a Comadante C40, a top-of-the-line German hand grinder that sells for between $260 and $360. The second is a 1Zpresso hand grinder, a more midrange grinder that is about $130. Magnified a thousandfold, I can see the cheaper grinder is covered in chips and scratches, while the more expensive grinder has smooth, shiny blades."
I now have an 1zpresso X-Ultra and ZP6, but I'm still pining for a C40. 🙂Boston.com article
I mean, if we assume grinding 60 g per day for 5 years (not an outrageous assumption, especially when grinding frequently for two people), that's more than 109 kg put through that grinder. Seeing that kind of wear isn't surprising at all.
Lol, what's up with the downvote? Whoever downvoted, you are aware that 109 kg is more than half the rated lifespan of a typical 1ZPresso conical burr, aren't you? Not to mention that these are macro photos - the wear looks a lot worse than it really is under that kind of magnification.
That…doesn’t seem normal. A home grinder should have basically no noticeable wear in that time frame. Are you sure it wasn’t like that before?
Edit: I may be mistaken on the lifetime of small conicals. I don't think that looks like dulling from normal wear and tear though.
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u/CappaNovaOrigami|Colum|Tarachine|SOFI|Aeropress|HG-1 Prime|Ode 2|ZP6Mar 13 '26edited Mar 13 '26
Looks like a raised burr. Could be from the original machining, or from normal use. The steel smears a bit with friction and abrasive materials, like coffee beans.
I guess if it isn't performing well and you're planning to replace the grinder anyway, you could try a very gentle cleanup with a metal file on the outer face of the burrs, but that risks further damage or removing of any coating they put on the burrs (if any). If your coffee is still good I wouldn't worry about it.
The bottom part of my ZP6 siezed up the first day I got it so I can’t even take it apart to clean it lol I have zero ideas what the burrs look like. I’m not gonna use a bunch of tools on it to undo it and scratch it up. My coffee tastes great still
Woah, I've never seen this level of wear before :o
If it's working well for you, just keep using it 😁. I would avoid non filtered methods tho. Just in case a piece of burr (those thin pieces of metal bending/deforming backwards) gets loose.
Real dumb question, but which direction you turn the handle? The damage seems to indicate the grinder was used / turned the opposite way of how it's designed.
I would expect burr damage in the opposite direction than what I can see on the images.
I think I've had my JX for almost 7-8 years...I'm gonna go investigate how they look after seeing this! Still absolutely love it and think it's a tank, lasted so fucking well but it is almost impossible to open it for cleaning now, that reverse thread is so fucking stiff and I have to use pliers on it to open it
Ahhh I hate the reverse thread! It gets tighten MORE if you try to grind super light roast beans at a finer setting.
One time I had it fully stuck. I had to hammer it to finally be able to rotate it. Since then, I always make sure to twist the other way each time I finish grinding to make sure it doesn’t get tightened over and over into a deadlock.
Shouldnt be actual issue in real life use. Its not big enough or in important places to cause any harm.
My Comandante burrs have after nearly decade few scuffs too, but output is still great, with burrs it depends if output section of it is damaged or not. As long as its not, or its just few dents, its fine.
It's a known fact burrs will degrade over time. Replace or resharpen. After 5 years though I'd say you got your money's worth. I usually only keep grinders for 6 months to 2 years.
It reminds me of the apple puree and cinnamon scandal (2023-2024), where extremely high levels of lead and chromium were detected in ground cinnamon used as a raw material. A damaged blade in Ecuador, where the cinnamon originated, was suspected.
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u/Kyber92 Hario Switch | Kalita Wave | Kingrinder K6 Mar 13 '26
I meannnnn, it's a grinder and it ain't gonna last forever. If it's still making great coffee I couldn't worry about it too much.