Tak jak pisali koledzy przed, tu masz pełen tekst konstruktora:
"Observation
Feed rate of beans through the burrs changes particle size distribution.
Slower feed rate results in coarser particles size distribution overall, while faster feed rate results in finer particle size distribution. So slower feed rate produces faster flowing espresso than faster feed rate for exact same distance between burrs.
Feed rate is influenced by motor speed, i.e. RPM (rotations per minute), by actual feed of beans through the burrs and burr surface roughness.
This is easily testable. Grind whole dose of beans and pull a shot. Then grind bean by bean the same dose and pull the shot. Second shot will flow significantly faster indicating the feed rate effect on the particle size distribution.
It stands to reason that the worst-case scenario is a random feed rate while coffee is ground for a shot of espresso. Since motor speed is constant, we focus on stabilizing the feed of the beans through the burrs.
In traditional hopper-based grinders full hopper of beans would provide constant feed rate and thus the best stability as far as the particle size distribution is concerned. In single dosing grinders, if there is excessive pop corning observed it indicates irregular and often totally random feed rate of beans into the burr and this results in random particle size distribution effect.
Solution
Monolith Conical uses low RPM's which reduced, but not eliminated pop-corning.
To stabilize feed rate, MC4-Duo, introduces a second conical burr made in house which does stage 1 coarse pre-grinding of the beans which is then fed into the stage 2 standard conical burr for final grinding. Buffer between stages is created to stabilize the flow in second stage. We have observed that this eliminates pop-corning almost completely in stage 2 and stabilizes the feed rate and thus produces the most consistently stable particle size distribution. The coarse portion of the bottom conical burr now acts as the auger instead of bean crusher providing more consistent feed rate of coffee into the burrs.
Difference between this approach and dual burr DRM Cimbali is the usage of the buffer between grinding stages which decouples coarse and fine grinding and stabilizes feed to the fine grinding stage. DRM Cimbali approach does not use the buffer so its vulnerable to variable feed rate due to popcorning.
This has been in testing for over a year. I have done lot of blind tasting with MC3. Process was very simple, dial in shots with both grinders, pull and taste blind without knowing which one came from which grinder. Then pick the shot which taste better to me. In over 90% of cases I liked MC4 shots better.
As for taste difference, its important to be honest, once you get to this level of grinders, the taste differences will not be night and day. I don't think that is possible. But there is an improvement in taste. Its not night and day difference but there is difference."
Tu masz trochę o tej koncepcji, domowy sposób:
A tu post, o DRM, czyli chyba pierwszej implementacji pomysłu:
https://www.home-barista.com/knockbox/little-ditty-about-drm-srl-hybrid-burr-type-t51913.htmlJa miałem zestaw żaren DRM w Hedone Honne, robiły świetną robotę.
