Jim Cleaves wrote:Lots of interest in raised bed- we have partcipated in some testing that had inconclusive results.
Very good point - raised bed is often mentioned as superior, but I also haven't seen any conclusive data. I think one reason for many folks' negative association with drying on the ground is much of the stuff you see along the side of the road in coffee origns, i.e. dirty coffee on a tarp, collecting road dust and rocks, chickens walking all over it, etc. Estates often have quite well advanced patio drying, but that is often overlooked in the raised vs ground debate.
If space allows I will casually experiment with some patio drying here in Burundi and see if cupping can lend any results when compared with their standard raised bed.
Sean Starke wrote: in several areas in Brazil I've seen drying done on raised polipropelene tarps (about a meter off the ground) that allowed air to circulate fully around.
Sean - are these standard poly tarps or do they have some sort of porous quality that would allow for air flow through the tarp and up into the bottom of the coffee batch? For air flow, I can't see how a standard poly tarp would be better than the wire mesh of most raised beds.
Jim Cleaves wrote:In Burundi June 2010 I saw washing stations that were drying the coffee on raised beds, but instead of spreading the parchment into a smooth surface, they groomed the parchment into little mounds or perhaps "pyramids".
Yup, that's it. I've heard it makes for less harsh sunlight assuming the mounds are rotated and the same beans aren't always on the outside surfaces.