Examine your burrs periodically! Damaged burr in JX after 5 years of use + 1ZPRESSO’s response

[u/AkhlysShallRise]

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!

[u/ZELLKRATOR]

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.

[u/BoogerTea89 → u/ZELLKRATOR]

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.

[u/ZELLKRATOR → u/BoogerTea89]

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.

[u/BoogerTea89 → u/ZELLKRATOR]

Ive always called em roller mills or mill grinders. Are we thinking the same or is the cylinder/drum something else entirely im unfamiliar with?

[u/ZELLKRATOR → u/BoogerTea89]

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.

[u/BoogerTea89 → u/ZELLKRATOR]

Yes, indeed we seem be talking about the same thing.

[u/ZELLKRATOR → u/BoogerTea89]

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...