Assuming the beans will be stored in a air conditioned environment, the beans ought to be good to roast by the time they reach 11-12% moisture content. You can test this without special lab equipment by tossing a sample in an oven/dehydrator @ 220F for 24 hours and then calculating decrease in mass for MC. That said, a decent water meter runs about $100-$300.

Water activity is still being actively researched (the team over at Cafe Imports released a very good study) and is not a definitive, stand-alone qualifier in regards to how a certain bean will perform from roast to brew.

Apologies if that doesn't directly answer your question, it really depends on what MC the beans are at by the time you pick them up and storage conditions.

@WeirdBros said:

Assuming the beans will be stored in a air conditioned environment, the beans ought to be good to roast by the time they reach 11-12% moisture content. You can test this without special lab equipment by tossing a sample in an oven/dehydrator @ 220F for 24 hours and then calculating decrease in mass for MC. That said, a decent water meter runs about $100-$300.

Water activity is still being actively researched (the team over at Cafe Imports released a very good study) and is not a definitive, stand-alone qualifier in regards to how a certain bean will perform from roast to brew.

Apologies if that doesn't directly answer your question, it really depends on what MC the beans are at by the time you pick them up and storage conditions.

Just to clarify the beans have been already dried and are at the milling station in parchment for the washed, and dried cherry for the naturals. The moisture content itself is now where it should be, but how milling stations work is that the last part (the de-hulling (trilla) from parchment or cherry is done at the last possible minute before leaving the station. They'll be hulled, size sorted, density sorted and electronically sorted, and packed all within a few hours before leaving the mill.

The moisture is fine, I have a moisture meter and by they're long dry now. But when you hull them right before they exit the mill wether its from parchment or dried cherry the green beans are suddenly exposed to air and allegedly the water activity jumps then. Sadly measuring the water activity is out of the reach of many of us due to the cost of the equipment.

But I've heard things from just give it 24-48 hrs, up to a month depending on who I have asked. The beans will be in my roastery storage within 24 hours after being hulled, sorted and packed in grain pros. Generally speaking for most of you it'll take over a month (most of the time a lot longer than that) from that stage to receive them due to shipping, but since we're a two hour drive from the milling station (El Borbollon) we really don't know how long to wait.

I've heard all sorts of opinions but have yet to find an actual source on this. Some people say wait longer for washed, some say wait longer for naturals. Who knows 😅

Ah I've misread that then, my bad! Then imo this is a great opportunity for experimentation! Have you considered doing some test batches along regular intervals from as soon it it gets to your facility to maybe so a month out? Just to see if there is any appreciable difference in cup quality/flavor profile.

@raccroasters I once had an importer get me fresh samples within a week or two post milling from Ethiopia. Their comment was to expect a blanketing metallic flavor in the cup, especially with sample and light roast levels. It's not unlike trying to cup coffee an hour after roasting. I have no reason to believe it would be any different there.

We know from experience that coffee can cup higher or lower from a pre-ship sample vs arrival sample. So I would not be surprised if your coffee opens up after a month or two of rest post milling.

You should share your experience roasting and cupping the coffee post milling! One week, one month, two months. Could be a cool experiment.

Coffee producer here! I would wait at least a month before roasting. You need to let "rest" the coffee after having gone all that transformation at the mill so you can make the most out of it at the roasting process. If you have any other questions dont hesitate to message me

@1aga1 said:

Coffee producer here! I would wait at least a month before roasting. You need to let "rest" the coffee after having gone all that transformation at the mill so you can make the most out of it at the roasting process. If you have any other questions dont hesitate to message me

Thanks @1aga1 - This is very helpful!