Ok, branching from the low pressure brewing thread - I wanted to dig into the Mythos 1 Clima Pro for a bit.

This has been touted as key to the whole low pressure (6bar) and lower temperature brewing method.

The Mythos 1 has a lot of interested features, and I watched the online video delving into its development. The one feature that is supposed to be key to its performance is that the grinder has a heater built into it, which maintains the grinding chamber at 35c.

Now - when I read about the M1 and the heater, I figured it was to keep the burrs in alignment from thermal expansion. It is a well known phenomena that in busy shops, the grinder usually has to be adjust finer through the day as it gets busy and the burrs heat up.

Seemingly, it meant the grinds were getting coarser. But there was actual testing that said the particle size change was essentially negligible. But what was really happening is that the extractive parts of the coffee were more readily extracted when the grinds were at 35-55c in temperature. That was pretty interesting.

Also of note, was how exceedingly important the "clump crusher" was and that the grinder would not be on the market without this little flappy bit of plastic.

So, I'm wondering, as the proud owner of Ceado e37s "spraymaster" grinder, about modding my e37s to incorporate controlled heater and a similar plastic flappy mechanism. The heat is likely pretty easy. Silicone rubber wrap-around heaters are readily available. That's pretty easy as is embedding a heat controller inside the grinder.

The "clump crusher" is a bit more work - but I think it can be duplicated effectively with some food safe plastic and creative knife work. I think I'll use a HPET plastic milk or water jug (the sturdier kind of translucent plastic) as the donor material. If I can get this working, I'll be pretty happy. The Ceado e37s makes really great grinds. But the exit control forces you to choose between lots of clumps and boulders, or fluffy grinds all over your arm.

If I can successfully implement both, I'll crank the Linea Mini (with the smaller 0.6mm jet already in it) down to 6 bars and see what happens.

You can buy the clump crusher as a replacement part. Beware, many say Don't touch it with bare hands, use gloves.

You could, as many are, lightly microwave your beans right before grinding to simulate the heat.

If you're up near Sacramento you're welcome to stop by and check out the Mythos 1 and the whole low pressure rehash in action.

While the Myrhos definitely helps, I wouldn't wait to turn down your LMLM to 6 bar.

I'm in Silicon Valley, so it is a bit of a drive, but possible.

I've seen the "clump crusher" available as spare parts - but of course, doubtful if it will physically fit in the Ceado at all, since they don't share the same exit chute design.

Any chance you can measure yours? Perhaps also put a micrometer on the plastic and measure how thick it is? Any idea of what it is made of?


I think the heater solution is simpler than constructing a clump crusher equivalent. Purportedly, the heated ground coffee is a big part of the "magic".

I'll be down in Santa Clara working during the next week for the next month?

I'll measure the chute and let you know. The crusher is hard just to see inside the chute. I doubt I could get a micrometer on it with pulling it apart.

I agree wholeheartedly on the heat helping. A couple a months ago I unplugged the heater and spent 2 weeks fine tuning the cold shots and none of them compared to the first day after I plugged the heater back in.

I think it might be easier and more consistent for a home Barrista to use a bean heater. An adjustable temperature mini crock pot, tea kettle, or potpourri heater might be a possibility.

As @kipp Said, don;t wait to try lower pressure.
I'd been running @ 6bar and below for over a year before Michael and I started to investigate the long and low shots ( lower brew temp and longer time) that eventually turned in to the two posts ( LP Rehash and All in the Mix)

The hypothesis is that all of these factors together add up to a more uniform extraction by managing heat and mass transfer, so whilst the Mythos seems to be a key part of it for us, we don't really know what it is about the mythos that makes a difference.

In the post I postulate that its the heated grinds that help manage the temp gradient within the puck by reducing the Delta-T between the Coffee and the brew water, requiring less heat to reach equilibrium. But as has been shown by Hendon, Perger, Dashwood et al, this could lead to less fines and a wider particle distribution by grinding at a higher temp. By current thinking this is a bad thing.

But, what if the search for a more uniform grind size is a fools errand due the the fact that all parts of the puck don't extract at even rates? what if the mythos creates a more optimal profile to encourage a more uniform extraction gradient ?

we are planning further work with Greg Scace, and i hope that we can shed some light on this.

I guess we could get the same effect by simply letting the puck rest in a hot portafilter for a few minutes before brewing.




On the pressure question -

After installing the 0.6mm jet in the LMLM, I found I still had well over 300ml of water flow (aka, water debit) in 30 seconds. So I reduced the pressure until the water flow fell below the 300ml mark. That got me to the gauge reading about 8 - 8.5 bar during actual brewing.

Without a SCACE device, I really have no idea what the actual puck pressure is on my LMLM. The brew pressure gauge is tied into the 4-way cross-T that connects the preheated water feed and cold flow mix from the pump into the brew boiler. This is before the water restrictor jet in the brew path, so by changing it and the pump calibration - I'm not really sure any more. Just need the test instruments to tell for certain.