Aging Mazzer Mini--burrs?

[JJR2]

Have a Mazzer Mini grinder from about 2008 in home use. In about the last couple of years or so, the setting for a 25 sec espresso shot has gone from ~6.5 to ~5.25. Shots are pretty consistent at a given setting, but having to dial lower to get them. In the last week of use, have 10 second shots down into the 4's. Cleaned it thoroughly, but didn't help.
I don't think I've put 660 lbs through it, but I haven't been counting. The burrs don't look much different from photos of new ones. Time to replace the burrs?

 

[Musicphan]

I would clean them with a product like Grindz before I would buy new burrs. My mini is about that old and running fine with 2 x double shots per day.

 

[shadow745]

The OEM burr rating is a very general guideline as that's affected by bean density more than any other factor. Lighter equals more dense and more wear on the cutting edges. If your typical setting is still a good ways from being true 0 you're likely OK for now. Over the yrs the main indicator I paid attention to was grinding speed, given similar coffees/fineness levels were used. For example, a Rocky I replaced burrs in would take around 12-13 seconds for a 19 gram dose. Once those burrs had a few hundred lbs on them it was taking closer to 20 seconds. Some burrs also tend to cause more clumping as they wear, but that can be affected by the type of coffee, humidity, etc. as well. Over time dull burrs can cause more heat to be generated in the grounds as the friction increases. All of that said/done, for a very reasonable cost I'd likely swap out with a new set of OEM burrs and keep cranking.

 

[JJR2]

A regular package of the Urnex Grindz product costs about 2/3 as much as a new set of burrs. I ran some quick rice (pre-cooked) through it without noticeable improvement. Ordered the new OEM burrs, so we'll see how that turns out.

 

[shadow745]

A regular package of the Urnex Grindz product costs about 2/3 as much as a new set of burrs. I ran some quick rice (pre-cooked) through it without noticeable improvement. Ordered the new OEM burrs, so we'll see how that turns out.

Never been impressed with Grindz as it leaves residue behind that needs to be flushed out with wasted coffee. I use a brush/vacuum and never have any buildup. On gnarly burrs in used grinders I bought I have soaked burrs and carriers in Puly Caff detergent, hot water rinse and dry with a heat gun. Like new, no surface rust and back in business.