Made a blunder and learnt a lesson - it is NOT a good idea to soak burrs and aluminum parts of the grinder (e.g. upper burr carrier) in a coffee detergent!

Burrs got rusty very quickly and now have pretty much no bite to the touch.

Aluminum burr carrier became dull gray instead of shiny silver - see attached pic.

After this happened I researched online and it turns out this is a common occurrence with aluminum kitchenware - you can't put them in dishwasher either, same thing will happen.

Now, I don't think I totally mind the dull gray appearance of the burr carrier. But would this affect the longevity of the part and if I wanted to bring it back to that shiny finish, what would you recommend I do?

Boiling aluminium with vinegar in the water helps deoxide it a little. It's only a surface layer, could probably be polished away too.

Would leave it as is, the surface is likely become a bit oxidized but it will not affect anything, plus...you don't see the burr carrier...

Perhaps you can salvage your burrs by grinding some old beans or minute rice, it seems unlikely that phosphate cleaner is aggressive enough to affect burrs much, it could just be that dissolved gunk has settled on your burrs....would not throw them out just yet...

The only coffee "detergent" I use is Urnex Cafiza http://www.urnexbrand.com/attachments/C ... ner_GB.pdf which has as its detergent a form of TSP (tri sodium phosphate) which is a great cleaner but a rather aggressive one (it has been removed from most consumer available soaps).

All I use it for is what it was designed for, cleaning carafe, portafilter, back flushing my espresso machine. Works the treat to remove coffee residue (brewed coffee residue not ground coffee)

I doubt you have caused any irreparable damage to your grinder parts.

You may want to get some Grindz and run it through your burrs before you grind any coffee.

http://www.urnexbrand.com/products/grindz.aspx

I never use Grindz but in this case I would recommend it for your application.

I clean my Mazzer using my vacuum cleaner hose in the top (after removing the hopper). This seems to be all mine has needed over the years to keep it working and performing acceptably

Same thing happened to me a while ago. Tried various metal polishes like nevrdull, soaking and cooking in citric acid. Didn't have much effect. Finally tried a professional polishing wheel and polish, which did the job and got the burr-carrier shining again.

That is the way, imo. You have oxidized the aluminum and aluminum oxide is really hard stuff. I keep a small amount around and use it on a soft leather strop to polish and finish-hone knife blades.

bop wrote:Made a blunder and learnt a lesson - it is NOT a good idea to soak burrs and aluminum parts of the grinder (e.g. upper burr carrier) in a coffee detergent!

The real lesson here is that an obsession with laboratory level cleanliness inside a grinder will get you nowhere. In two or three shots, the leftover grinds will be back where they like to live. An occasional grind with one of the commercial grind cleaners like Puly Grind or Grindz is all you need.

Thanks everyone for the advice. I'll leave the carrier as is as I'm fine with the gray color and I'll keep in mind how to turn it back if I'd like to down the road.

Thanks for the Grindz suggestion as well - I'll try run some of that on the rusted blades.

And I agree more than one lesson was learnt this time I'll stick to brush and vacuum from now on.