Unexplained change in Mazzer grinding rate

[CoffeeOwl]

Hi!
My Mazzer Mini plays tricks with me.
Normally (read: up to now since I bought it) it produces about 15.5g of grinds in about 21s. That means if I grind for about 21s (using analog clock and eyes to measure) I get from 15.5 to nearly 16g of coffee.
Once it made the trick and produced 14g of coffee in 20s, but that moment I thought I misread the clock. But it probably wasn't the case, for the last 5 days it consistently produces about 14.5g of coffee in the same time (the weight is measured on accurate digital scale and the reason for measuring was noticeably less coffee in the basket).
What is this???
I know it doesn't depend on the beans because I was using 3 different coffees and Mazzer grinding rate was the same for all of them.
Help!!!

[Randy G.]

That small chage could be something like a bean caught in the burrs somewhere slowing the passage of coffee. I would pull the top burr out, give it all a good brushing out, and examine the burrs.

[CoffeeOwl]

Thanks Randy!
Today evening I took the hopper out, beans out of the throat, ground the remainings and turn it on, went coarser all the way up and back to citron finess. On the top-coarse turned it off and gave it a few thumps. Hopefully it will clean itself that way... as I remember reading something it's tough to mount the burrs back I'd rather it start grinding normally tomorrow morning.
I'll report back.

[CoffeeOwl]

Solved!

EDIT: nope, it went back on its weird way. I'll have to do a cleaning.

[Elbasso]

I can imagine the burrs getting less effective when the oils are caking up in the grooves. Take a look below.



Cleaning the Mazzer is pretty easy. I do it every three months or so. For a quick clean you can use Grindz which is pretty effective. Still, it doesn't get all the way into the grooves. For a real proper cleaning you have to unscrew the collar and take out the burrs. This thread will tell you how to do this: http://www.home-barista.com/forums/cleaning-mazzer-mini-t680.html

The most important thing is to mark or remember the point where the collar and threads disengage. This to prevent cross-threading the collar. I also find it useful to count how many rotations it takes to unscrew the collar. This makes it less scary to give it another full twist when putting it back on, even though you already feel a lot of resistance from the springs and might get scared of crushing the burrs into one another.

Hope this helps and good luck!

Elbasso