I recently upgraded my grinder from the Hario Mini Mill to the Virtuoso, which I am quite excited about. I am, however, having a bit of difficulty dialing in the settings. The virtuoso is a refurbished model, though I'm not sure if that has effects on my issues.

​

The recommended grind size for V60 on the Virtuoso is 15/40. I think it looks quite fine. I have only ever made V60 coffee with my mini mill, at 10 clicks. This grind seems much coarser, though my mini mill has lost some grind consistency, I believe. Here are the two side by side, Virtuoso on the Left, Hario on the right. When I made coffee, I didn't make a cup with the Hario ground coffee, only the Virtuoso. The bed came out horribly uneven, and the coffee was quite bitter. Then I decided to try a little bit coarser grind (18/40), which produced a worse bed, but less bitter coffee.

​

What is going on? Is my virtuoso grinding extraordinarily fine coffee? Have I been drinking swill from the mini mill? It's tasted good, I just can't seem to replicate it with the Virtuoso. Is my technique all wrong? I bloom 21g coffee with 42g water 40 secs off the boil, wat 30 secs, pour 159g water in a circular motion keeping the slurry level even, wait 30 secs, add the final 159g water, and it finishes draining for a total time between 2:10-2:30.

​

Similarly, my moka pot made decent coffee before with the Hario on 9 clicks, but the Virtuoso on 15/40 produces something like an IPA mixed with used engine oil.