[amarant]

Knowing how cool and nerdy coffee enthusiasts can get, do you know if any studies that support the rpm grinding difference in flavour?

I know a coffee grower who put his beans through a spectrometer to determine whether sun drying his beans actually altered the flavour profile compared to machine drying. He wanted to eliminate placebo mostly I think. He could demonstrate a clear difference in the spectrometer between sun dried and machine dried beans, with both batches of beans coming from the same field, the same year.

I just love how nerdy coffee nerds are!

[AnthonBerg]

I propose a mechanism that brings about the difference:

Higher speed cracks the brittle beans differently, smashing them into a higher proportion of fines.

Fine and coarse particles yield very different proportions of compounds into the water – the less soluble stuff kind of only washes off the surface of the ground particles. Finer particles, more surface, more of the hard-to-extract less soluble stuff.