Scaling Up Refining Times Based on Weight?

Hey All,

I'm wondering if, while using the same machine, folks increase their refining times linearly proportional to increased chocolate batch sizes. I use a Santha Spectra 11 melanguer. For the last year, I've been making 2-5 lb batches of chocolate and have observed that my best chocolates from a taste and texture standpoint have been in the Santha for about 5-6 hours per pound of chocolate. I recently refined my first 9 lb batch of chocolate for 41 hours, which is about 4.5 hours per pound. This chocolate has a noticeable bitter bite at the beginning/front-end of tasting it, but fortunately finishes quite nicely.

I'm questioning myself as to whether I should've melangued it for 45-54 hours (the 5-6 hour per pound range) as maybe it didn't conche long enough (or whether it was simply the beans.) I think I roasted the beans quite well as the nibs were tasty, slighty crunchy, and not chewy, but there was some bitterness.

I haven't forked out the cash to read the $200+ Minifie or Beckett books so I'm not sure where else to learn this info.

What have any of you observed? Would you scale-up, in the same machine, linearly as a function of refining time versus weight of chocolate? Have you observed something not so linear to successfully make larger batches of chocolate in the same machine?

Any guidance, feedback, or advice would definitely be appreciated!

Cheers,
Dave