Trouble Dialing in Mizen Burrs - Page 2

Beginner and pro baristas share tips and tricks for making espresso.
Bastian987
Posts: 43
Joined: 1 year ago

#11: Post by Bastian987 »

I'm now in a similar position. Two or three kilos through with the burrs, very careful puck prep on light and medium roasts. The shot looks great on a bottomless portafilter for the first couple of seconds, then starts to channel on almost every shot. I'm also a bit lost what could be the cause (doing WDT, RDT, level tamper). I'm happy to hear the Mizen should be easy, so there is hope and we just have to find my/our mistake.

Next, I will swap the Mizen against the HU I also purchased... let's see.

Abecker (original poster)
Posts: 238
Joined: 6 years ago

#12: Post by Abecker (original poster) replying to Bastian987 »

I have found two beans which have given me this issue and both were fairly light. A different bean roasted a little darker (more of a medium) didn't give me the same troubles.

Bastian987
Posts: 43
Joined: 1 year ago

#13: Post by Bastian987 »

Hm, for me, light roasts are a main motivation to move to burrs like the Mizen. Maybe turbo shots are the only viable path then and channeling cannot be avoided otherwise on light roasts? Or is this an incorrect conclusion?

zefkir
Posts: 271
Joined: 4 years ago

#14: Post by zefkir »

Mazzer conicals, or traditional Italian burrs are what should be used if one wants to avoid shots that flow fast and clear towards the second part of the shot.

So called high extracting burrs have already extracted most of the soluble and viscous compounds by the time you reach 1:1 especially if you grind fine enough to get a 18:36 25s shot. So for the second part of the shot, you're running low coffee concentration liquid through a puck that has already had most of its soluble extracted already.

Unsurprisingly, this looks ugly, especially with lighter roast that aren't very viscous to start with.

Bastian987
Posts: 43
Joined: 1 year ago

#15: Post by Bastian987 »

Interesting read. What's your personal conclusion? Channeling in the second half is normal and not an issue, and the shot still tastes fine? Or one should move to Turbo shots with those burrs and lighter roasts?

zefkir
Posts: 271
Joined: 4 years ago

#16: Post by zefkir »

I turboshot everything. Including the very rare dark roasts, though for dark roasts, I turbo with 1:1.5.

Sidenote, I think people often mistake a loss of fluid viscosity and a flow flow acceleration for channeling. If all the puck sees that flow acceleration and loss of viscosity, it's just how the shot flow. If part of the puck sees flow acceleration and loss of viscosity, it's channeling.
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buckersss
Supporter ♡
Posts: 578
Joined: 3 years ago

#17: Post by buckersss »

In similar situations I tried upping the dose in my basket by 1g, 2g or even more at times. It's hard to draw conclusion but I think it helped my shot.

Bastian987
Posts: 43
Joined: 1 year ago

#18: Post by Bastian987 »

Thanks for this hint, first tests indicate this helps in my case as well.

Looking at more shots in my bottomless portafilter in general: I feel fast extracting burrs is a good description. It's in my case not "typical" channeling, i.e. not a normal (mainly dark brown) looking extraction with view channels shooting almost pure water. Instead, the entire shot is moving quickly from dark to blonde and entire regions look very watery... like there is nothing left to be extracted.