Wybo could not tell me much about filters but he did have a brilliant offer:
"No, I was never seriously involved in these little filters so I can't tell you anything about them. As a matter of fact I hate filters --- they tend to get clogged on the most inconvenient moments, especially if for some reason you want to filter out relatively small particles.I was quite thrilled of course and in a hurry to pick up this gem. Until I had time to do so, I read the PDF of the manual which was available online and I watched some online video's about centrifugal separation. A machine like that needs careful treatment because even with relative small amounts of fluid rotating at thousands of RPM, the G-forces can be substantial and an imbalance can cause havoc.
That's why I prefer to use an excellent centrifuge. I've got one here -- up to 4000 rotations per minute, electronically controllable, programmable including rates of accelleration and slowing down to avoid any turbulence during those phases.
I have no clue as to what you're trying to accomplish with coffee, but if it is of any use to you you're welcome to have it. Mind you, it's a heavy thing measuring 40x45x50cm."
So here it is, the Espresso Centrifuge next to the Londinium I:
|Hettich Rotanta /P Centrifuge|
Time to brew some espresso! I used 20g of the Panama Los Lajones from Graziano Cruz which I roasted two weeks ago. Got 30.3g extraction:
|30.3g of espresso from 20g grinds on the Londinium I|
Next I weighed off 7g of the (stirred) espresso in a test tube and also 7g of water in a matching test tube:
|Two identical test tubes, both filled with 7g, one water, one espresso|
|Coffee and water of equal weight in matching seats, ready for the ride|
|Break force 3, rotation speed 3000 per minute, ready to start|
I measured the sample straight from the test tube, using a new pipette onto the calibrated refractometer and read 9.6 % TDS:
|9.6% TDS on sample out of centrifuge|
|Yay! Filtered sample out of espresso source gives identical reading|
I will need to do more testing and I will specifically be trying to find out the best rotation speed and the optimal duration of the centrifugal separation. There was some sediment visible in the bottom tip of the test tube but I think the fluid could be separated even better. And then I could save this sequence into a numbered program, including the time to reach max RPM and the time to slow down to the full stop. I will then be able to reproduce the exact same procedure every time.
With this machine I can skip filtration if I want to.
Thank you Wybo for this beautiful device!