Plugged grinder burrs! - Page 2

Grinders are one of the keys to exceptional espresso. Discuss them here.

Postby walt_in_hawaii » Jun 13, 2018, 7:21 pm

Richard, thanks for the suggestion. I've never used Minute Rice; I think I'm too much of an oriental snob :)
is it anything like real rice? got plenty of that.


Postby OldNuc » Jun 13, 2018, 7:36 pm

Real rice is too hard, need to use cooked and dehydrated rice, Minute Rice.


Postby EddyQ » Jun 13, 2018, 10:27 pm

Someone here once posted that rolled oats cleans burrs rather well. I have not tried it.


Postby walt_in_hawaii » Jun 13, 2018, 11:38 pm

now, rolled oats I got PLENTY of! (I'm mostly vegan) Thanks eddyq! I gotta go hit home depot on the way home.... pick up some acetone, need a strong nonpolar solvent to see if there's anything on the surface of the burrs that is making oils stick there. cheap enough test. carburetor cleaner is too expensive! not to mention carcinogeous.


Postby walt_in_hawaii » Jun 14, 2018, 2:13 am

Update: too lazy to go look for the minute rice. Went to get the acetone, though; but after I got home, too tired to take it apart so I just ran about a half cup of oats (dry oatmeal) through it.... came out looking like a coarse flour! Used a couple different grind settings, one quite fine.
Then ran some Guji beans through it... light roast. Surprisingly, it didn't clog. There was residual white powder from the oatmeal. I ran it fine, fine enough for an espresso... didn't clog! hmmm. interesting.

Took the burrs apart and cleaned well, with a brush, reassembled, and put in my normal 50/50 mix of harrar and jacinto (brazil), 8.5g. The first shot was a tad too fine... but no clogging! went coarser, so of course next shot came out fine without clogging either.

I've never posted a video, I'll try to get some help to do that. Its quite a long pull, only 8.5g but about a 20sec infusion (1 bar) and by my watch close to 1:20sec pull? much too long, but the look of it was pretty good and the taste was GREAT. very sweet. Clogging issue solved? not sure. we'll see in the next few days if it rears its ugly head again....

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Postby Jake_G » Jul 01, 2018, 8:19 pm

Hey Walt!

Loving what you're doing to the K10, by the way. Have you had any more clogging adventures with Signor Super Jolly?

I haven't had a single "episode" for about 6 weeks now, which means I should be due! Did you get the K10 to replace the FrankenJolly, or to compliment it?


- Jake


Postby walt_in_hawaii » Jul 02, 2018, 11:37 am

Hi Jake... good to hear from ya!
Well, the K10 is a conical, and the SJ is a flat, and they are roughly the same size diametrically, but of course the surface area involved in the burr designs is radically larger in the conical design. I had always intended to get one of each, as I don't have enough time with both types to develop an opinion about which one I prefer. My thought was to figure out which one I liked better, and use that one as my primary grinder. The secondary I will keep but probably use for decaf at night.

I have not had any more plugging issues with the SJ at all... haven't really run too many batches through it, though, mostly using the K10 at the moment... if your SJ still plugs, I would highly suggest running the oatmeal through it, I think I ran 3 handfuls through mine and it hasn't clogged since! Not really sure why... but not complaining!


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Postby Jake_G » Jul 14, 2018, 11:22 am

Did it to me this morning.

Put a puff of steam for RDT on some medium-light roasted El Esperanza Guatemala Bourbon from Equiano Coffee and dropped them into the throat.

Clicked on the timer switch and... round and round they go. Nothing out the discharge.

While the burrs were still whirring, I cranked the adjustment 30 to 45° in the coarse direction. The tone changed and I snapped it back to my original grind setting and all my beans were ground up and happily exited the chute into the doser.

As I mentioned earlier, the odd thing here is the resulting shot. A full 25 seconds of line pressure preinfusion before the bottom of the basket was dripping gently. Kicked on the pump and had a nice ~28 second extraction that pulled really evenly.

About to go pull a second shot but I can pretty much guarantee that I'll have trouble-free grinding for the next long while. No disassembly or oatmeal or minute rice or anything else required. Just a quick nudge to open the burrs so they bite the beans and then back to target grind setting. I would expect that going super coarse to get the beans to pull through would result in a fast flowing shot, but this never seems to be the case. They always come out slower, but still plenty tasty. Must have something to do with pre-breaking most of the beans into smaller bits while the burrs are whirring but not grinding. Then, even though the first chunks through are very coarsely ground, the remaining portion of the dose must have a smaller average particle size than when grinding a dose of whole beans. There was not an abundance of fines in the cup...

Anyway, I'm mostly posting this to document mean time between clogging. But it's not really "clogging". It's just choosing not to pull the beans into the burrs for whatever reason. Also of note is that these beans are pea berry sized. Not big at all. Will have to keep an eye on bean size the next time this happens...


- Jake