Professional & home roasts - Considering the grind

[CakeBoy]

Have borrowed Soapy's box for a few minutes, but I can't stay long as he makes me wash and polish it afterwards .

A topic for all you experienced roasters to help those of us that are less knowledgeable .

As many of you know, I am very new to home roasting and use the fluid air method. It has been interesting for me to consider the differences between Steve's world class professional roasts and those from my IMEX. Before you start rolling on the floor laughing, I don't mean compare as in quality, because that is like considering a Ferrari with an old Lada .

I am referring to the difference required in the grind. My home roasts of the same or very similar beans have to be ground much finer for expresso than Steve's. The tamp has to be considerably harder too.

Now there is probably some scientific reason for this and I expect it is related to fluid bed vs fluid air techniques with their differing roast times and the moisture content left in the beans, and someone will be able to tell me right away. However, I thought it interesting enough to ask what others have found, whether they have worked out why the differences exist and if they have made any adjustments accordingly .

[fred25]

But then this could all be total B^&&()

Is that B for barbecue?

More seriously, and since I know nothing of professional (ie. proper ) roasting, what is 'fluid-bed' roasting?

(by the way, if anyone is interested in modding their popper with a speed regulator as described in the article: 'modding a popper with a light dimmer: addendum', please let me know! I bought the piece from CPC but haven't got round to modding my popper. Roasting bean by bean is driving me nuts, so I think I'm gonna go the heatgun way... Should be fun, especially as I intent to do it indoors! MWAHAHAHAHAHAHA )

[blackice]

less humidity+less oils->drier beans->finer grind adjustment

the imex because of the strong air flow dehysrates the beans more than ie a drum --> drier beans
because of the fast (rather superficial) roast-->less oils

so we have drier beans which require finer grind adjustment


PS
when I roast darker which result to beans with oil on surface I always expect the need for corser grind adjustment and thet's 99% true. Lighter roasts --> finer adjustments. The difference is quite small though.

[Beanie]

...have to be ground much finer for expresso than Steve's.

Tar and feather this boy!!!

I expect it is related to fluid bed vs fluid air techniques with their differing roast times and the moisture content left in the beans, .

Uhm, what's the difference btwn fluid bed vs fluid air?