This topic will likely transform into “Things not to do when moding a grinder”…
Let me start by listing the setup.
- Inverter connected directly to the grinder motor. Do not connect the grinder plug directly into inverter output, you will blow up grinder switch electronics, ask me how I know.
- DF 64 with SSP red speed HU
- Mythos clump crusher mod
- Normcore autolevel tamper
- Silvia Pro espresso machine
- VST basket (20g used in these tests) and naked portafilter
- Normcore puck screen
- Red brick coffee beans roasted on 31 Jan
Normally, for these beans I dial in 18g in, 34g out, ideally 24-28 sec.
For today session I tried test the differences between 1480rpm mains 50Hz and 1000rpm 35Hz with inverter. TLDR, I tasted virtually no difference in shots.
Today session started with a bit of a fail. Previously, I tried some random lower speeds and noticed that grounds did not flow out quite efficiently, clogging up around the clump crusher and I decided to remove it. The result of that was that I got not only clumps, but also the entire chute clogged after 3 grindings of 18g - bad idea.
I cleaned everything up and put back the clump crusher, dialed in at 50Hz full rpm got 24 sec shot. I repeated the process with exactly the same settings but at 35Hz 1000rmp this time and got a 28 sec shot. Usually these kind of differences in shot times happens often, it is basically hit and miss if I try to make it exactly the same. I gave it another go at full rmp hoping I get the same shot time, and even worst, I got 21 sec. At this point grinder was noticeable warm for which I blame the drift in settings. (Side note, usually with the grinder warm, if I chase the grind settings to bring the shot time back up to 27-28, next time when grinder is cold those settings will be waay to fine, giving 35-50 sec shot, so it needs another dial in and wasted beans).
So as I said, virtually no difference in taste, maybe the 1000rpm was slightly better extracted but that is probably because of 28 vs 24 sec difference. Definitely no new notes, flavours or anything else. Just like any other good extraction I got from this setup at full rpm.