Grinder cleaning - when and how?

Grinders are one of the keys to exceptional espresso. Discuss them here.
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#1: Post by arcitek »

I am quite new to this whole home-espresso thing. I got into it by purchasing a Delonghi EC155 almost a year ago and would have 1/2 lb. bags ground for me at local roaster. Had some good experiences once in awhile (when compared to Starbucks or something) but it was fleeting. Decided I needed a grinder and became consumed with research which drew me deep into the world of real espresso.

This all started 3 weeks ago which led to me turning my EC155 portafilter into a naked portafilter, purchasing a new Vario grinder for 357 dollars, and ordering freshly roasted coffee online for the first time ever. Ground my first portafilter with fresh coffee and wow....what an immediate difference! I had a good layer of a darker golden crema and the shot tasted so much better than anything I had done. It was far from perfect I am sure and my head is still swimming information on what to do-not do but very gratifying to make this jump.

I was on sweet marias looking at samples of good shots and the color of crema. Good information there to help guide me to improve what I am doing. My one question is how often should I clean out my grinder? It is a genuine pain to pull the hopper off to get out unused beans and grinds so I am not doing it after every grind which is probably 2 - 3 times per day. How often does everyone clean theirs and do you run rice or grindz through to clean after each grind? I'm asking because I just read somewhere that the number one problem with bitter espresso is an unclean grinder or espresso machine. the leftover grinds go stale quickly so it was said they should all be removed after every grind. Is this true?

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#2: Post by Chert »

It depends on the grinder and the barista. Some grinders have a path that retains alot of ground coffee. This can stale and then affect a followup shot. To avoid this problem, one seeks a grinder with a short path between burrs and portafilter. I use hand grinders or a Baratza Vario and I don't store whole beans in the grinder (usually and if then not coffees with alot of oily sheen that would remain behind on the hopper etc and go stale).

So after use there is little to go stale. I rarely clean any of my grinders but they all see nearly daily use and so the first shot in the grinder may have something (probably quite a bit) less than .5 gram. I don't think that small amount makes any difference.

If I want stale coffee, I just have to dismantle my Pharos as some drifts into a closed off space between funnel and lower ring.

Happy better-and-better-and-better espresso journey!
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#3: Post by darilon »

With my electric grinders, I will some times do a quick 3-5 second pulse to remove any stale grinds from the grinding path and then clear out the doser (both of my electric grinders are doser models). With the Pharos there's really almost nothing left inside the grinder to go stale. If it's 15 seconds or less between shots then it doesn't matter. I've played around with all sorts of levels of obsession regarding this matter, and have settled on my current low key approach with no noticable detriment in the cup for the time being.

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#4: Post by pacificmanitou »

I don't concern myself with stale grounds on a vario, I've measured retention to be under half a gram. It's also good for single dosing because of this. Baratza makes a trapdoor hopper that would make it considerably easier to remove and clean the burrs, if you're concerned.
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#5: Post by boar_d_laze »

The purpose of cleaning the burrs is to clean the burrs. Cleaning retained grinds is a different thing. Let's start with cleaning the burrs.

I. Cleaning the Burrs:
Grinds and oils stick to the burrs and may become rancid if not removed. Clean the burrs when you notice an off taste or at least once a month as prophylactic maintenance.

A. Cleaning with Instant Rice or Grindz
There's no need to remove the hopper for cleaning with a cleaning material. Simply empty the hopper and reserve the beans so you can replace them after cleaning.

Set the grinder to the equivalent of a very coarse espresso or very fine drip grind. Then load the cleaning material -- either INSTANT RICE (do not use raw rice or par-boiled rice) or GRINDZ into the hopper. The amount of cleaning material you need to clean the burrs depends on the size of the grinder. In the case of a Vario, an ounce should be enough.

Run the grinder until all of the cleaning material has been ground and you can hear the burrs "running on empty."

After cleaning the burrs in this way, you'll need to "re-season" them and remove any cleaner caught between them or in the path by running an ounce or so of inexpensive beans through the grinder.

Clean the interior of the hopper with a damp towel. Wash out your grinds container if you have one. Clean the exterior of the grinder as completely as you can.

When everything is clean and dry, you'll need to dial-in your good beans as though from scratch.

B. Cleaning by Brushing and/or Washing
Every six months or so, it's a good idea to remove the burrs; inspect them to make sure they're still sharp and in good shape; and clean them by brushing and/or washing.

Of course, you'll have to empty and remove the hopper, first.

If you wash, make sure the burrs are thoroughly dry before reassembly. It's a good idea to air-dry on a rack overnight.

When you reassemble the grinder, you'll have to re-zero (aka re-calibrate) the grinder. Then you'll need to re-season and dial-in again.

II. Cleaning Out Retained Grounds:
I don't know about zero retention, but your Vario is definitely at the low end of the scale. However even so-called "zero retention" grinders retain at least a few grounds and you might as well tweak your regimen to get rid of them.

Brush the chute before grinding, and brush it at the end of every session.

Any time the grinder's sat idle for more than an hour or so, it's a good idea to blow out the chamber and chute by grinding an appropriate amount of beans. For your Vario and my Bunnzilla, that's a very low dose -- about 5g. In the case of other grinders, my Ceado for instance, it's more like 10g -20g.

III. Trouble Shooting:
The more you get used to drinking good espresso, the more sensitive your palate will become to bad espresso, and the better able you'll be to identify flaws. When you detect stale, "off" or "harsh" tastes, it's a good idea to start by cleaning to get rid of any possible contaminants in the grinder, the pf, or the head.
  • For one thing, it's effective surprisingly often;
  • For another, it's quick, easy and more or less free; and
  • For a third, you have to do it anyway. So what can you lose?
Hope this helps,
Drop a nickel in the pot Joe. Takin' it slow. Waiter, waiter, percolator

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#6: Post by cannonfodder »

I have a different grinder but I brush the discharge chute out after grinding then before I grind my next shot later in the day I give the grinder a quick 2 second pulse to clean out anything left in there. Then dose it into the grinds catch tray and grind my shot. I only clean the burrs every year of so but I do not use dark roasted oily beans which are very bad about leaving oils and caked on dust behind. I will on occasion take the grinder outside and hit it with the air compressor to blow the grind chamber out. If you do that, turn the pressure down to around 60psi and blow out the grinder from discharge chute and out the hopper not down the hopper and out the discharge chute. Make sure you are not standing over the grinder when you do it unless you like to sand blast your face with coffee.
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#7: Post by Peppersass »

I can't remember the last time I cleaned the burrs in my K10 with Grindz. I've not found it necessary to do that on a regular basis.

My cleaning regimen is similar to Dave's, and I also avoid oily coffees. I single dose and thoroughly sweep out the chute after each grind. I also use a brush to push chaff and small particles down through the burrs before pulsing to clear the burrs and chute.

About once week, when I do a detergent backflush on the espresso machine, I use a shop vac to suck out any loose debris in the grind path.

I've never removed the burrs from my grinder, nor have I opened the burr chamber. The burrs in my grinder are rated for decades of grinding at the volumes I use.

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#8: Post by Philg »

If you're going to brush ground coffee out of the chute after you grind (I do this every time I grind, btw) remember the burrs keep spinning after the motor stops.

I don't know the Vario but with my SJ, the burrs are close enough to catch the bristles and jam the grinder, I learned this the very first time I used my SJ, only luck that I didn't try to clean the grounds out with my finger.

Enjoy your new grinder, sounds great!


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#9: Post by JohnB. »

I run the K10 with my shop vac nozzle over the chute each morning to pull out any loose stale grinds. Every two to three weeks I spin off the upper burr assy & sweep/vacuum out the burr chamber & clean off the burrs. I also wipe down the surface of the chamber & the sweeper with a paper towel soaked with rubbing alcohol.

I've tried the Grindz cleaning method but IMO it's ineffective & just creates more of a mess inside.

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#10: Post by beer&mathematics »

Get one of these
rocket air blower
And single dose and use the above tips
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