Help required with Mazzer Mini E type A

[Shotgun]

Hi all,
I've noticed almost all the barista's around are using electric Mazzer's these days and I liked the fact that there were no stale grinds left overnight in the doser (as per my Mazzer with doser)
I splurged on a new Mini E and since I installed it I don't think I've pulled a decent shot.
I had a system with the old grinder where I achieved consistency but with this new setup I never seem to be able to pull 2 shots the same. One will be very slow and the next shot will pour out very quickly.
I weigh my portafilter then dose the exact weight into the basket (within a gram or so) but still have inconsistent results.
Does anyone know where I might be able to watch a video of dosing and pulling shots with one of these auto grinders. I really do need help.
Cheers
Shotgun

[timdimdom]

hey shotgun
congrats on a great purchase!
unfortunately no grinder is perfect... and it sounds like what you're dealing with is the grinds in the chute just as it exits the grinder delaying your adjustments. from experience the mini e would retain around 2g of coffee in the path between the bottom of the burrs and the chute opening behind the static screen

the 2 ways to deal with this would be to purge around 2-4 g of coffee before using any coffee after that, or taking the left over grinds out with a camera cleaner/air brush. just leave the pf in the bottom and clear out the retained grinds.

this is a vid showing the major retaining about 1.5g
https://www.youtube.com/watch?v=KnSpcn5ZBDM

This will make your adjustments to grind delay between shots and barista schools will teach that you need to only factor in the most recent grind change on the 2nd shot you pull after an adjustment.


the other thing is that fresh burrs tend to need seasoning before they generate less clumping which could be another cause of your channelling. this just needs some redistribution or tamping adjustment...
https://www.youtube.com/watch?v=atM61y3CavQ this guy takes out the clumping with all that brushing


finally, i wonder what accuracy scale you are using. if it is in 1g increments you might be getting quite far off in terms of dose as 1g can make a huge difference in resistance of the puck and clearance from the shower screen which might be another variable you might need to address


hope this helps!
tim

[DesigningByCoffee]

Hey Shotgun
With these grind-on-demand grinders, I've found that the first shot ground through an empty grinder often pours much faster than the following shots - is certainly true with my Robur. If the grinder is clean and empty, I'll run 2-3 doubles before it starts to settle into the grind setting I know from experience should give good results. Once you load your hopper up consistently, get the grind right, run a a few grams through, then grind by weight, it should improve from there.
But if you decide you're going to single dose (measuring into an empty hopper, grinding everything then sweeping everything out) then you should get a more consistent result - just with more fiddle while you get your technique established! Also - this technique will likely require a much finer grind setting - so you can't really go back and forward between the two methods easily…

Cheers Matt

[Shotgun]

Hey guys thanks so much. This is the first chance I've had to return to this thread so I'm sorry about going missing in action.
I really appreciate your support here fellas.

[Shotgun]

I'm only using Accura kitchen scales which are 1g increments. I didn't want to spend $200 plus on scales. Maybe I'm defeating the purpose.

[woodenteapot]

You can get some digital scales with 0.1g accuracy for less than $20 online. I've been using them for awhile now and works great.

Alternatively, have a look into something like the Brewista smart scale - it's much cheaper than the awesome Acaia scales, but it's accurate and has a built in timer.

I single dose my Mazzer Major at home and find it is great for consistency, but as the burrs heat up after a few double shots in a row, I find that I need to start "tightening" the grind setting to achieve the same flow rate.

[Blue_House]

We find that 0.2 to 0.4 grams is the outside discrepancy from shot to shot if you are looking for consistency. Unfortunately 1 gram scales won't achieve that result. Happily, you don't need to spend $200 the Brewista Smart Scale does just about everything you need for less than half of that.

[DesigningByCoffee]

I've just bought some $13 evilbay 0.01g jeweller scales - they work a treat and I don't get in trouble for nicking the kitchen scales anymore!

[Dimal]

Me either...

I get in trouble now when I nick the kitchen scales on roast days....

Mal.