Water Loss during roasting

[itsallaroundyou]

general questions for all the cacao roasters:

do you aim for a certain percent water loss after roasting, or just roast until you think the beans are done? If the latter, what range of % water loss do you normally see?

-mike

[FeralOne]

I don't do my roasting for water retention/loss. I have my roasting profiles set for what suits my tastes. I haven't actually checked the water evaporation % for a long while, but it was around 2-4% when I used to check it. A good supply of cocoa beans will be mostly dry when you receive them, if you are experiencing high amounts of loss after your roastings you are not getting a good bean.

Andrea

[Brad]

Mike;

Further to what Andrea noted, I don't check moisture loss either. However both Andrea and myself are lucky to be in very dry climates. Here in Calgary, our beans arrive at around 7-8% humidity, and just by sitting in our storage area reduce in a couple of weeks to less than 4% humidity.

Cocoa beans are very hygroscopic - meaning they are very succeptible to absorbing moisture from the air. If the area of California you live in is very humid, and your beans sit for any period of time (like a week or two), they will very likely increase in overal humidity and weight. So, while your beans arrive from your supplier relatively dry (say around 8%), they may increase to as much as 15% just by sitting on your shelf for even a relatively short period of time.

This is also important from a pathogen standpoint. I've read in various publications where a moisture content of more than 8% relative humidity, puts you in a danger zone for pathogen, and pest growth on the surface of the beans.

Best Regards,
Brad.

[itsallaroundyou]

Andrea and Brad--thanks for your replies.....it has been really humid here (not like tropical jungle, but more than usual since we just got a big rain storm, followed by a heat wave), but my beans are still in the original plastic bag, so they should not have absorbed much from the air.

my most recent batch falls in line with the 2-4% weight loss post roast as Andrea noted. it was a fairly long roast too, so i don't think the beans were under roasted. when i originally calculated the loss, i thought i was way under the 6-8% that i read about.

is it detrimental to the bean's shelf life or quality to store with a desiccant in humid conditions? I don't have a nice climate controlled room to use, so if humidity got to be a bigger problem, i'd have to come up with something. luckily, i don't think it's so high to allow growth on the outside of the beans (i left a bowl of husks outside before the rain, and after was just a huge clump of mold, so i can see how easily it can happen)

[Brad]

With regard to the desiccant, I wouldn't think so. Silica gel packs work for other applications, and don't impart a flavour. I think if you used them in good sealed plastic bags you should be ok - although I don't know the size size of the bags you are using, or the quantities of the beans. I would guess if you're storing entire 120lb sacks then you would need sealed tubs.

Brad.

[itsallaroundyou]

the largest bag i have is 25lbs, and dropping quickly

i can get rechargeable silica gel from my lab, so i will go that route if it gets too damp.

[doclogic77]

This post makes me wonder if I should store in a room that has a dehumification device. It would be a real shame if hundreds of pounds of beans were tainted.

[tony]

I live in a very humid climate - at this time of the year averaging btwn 66 - 85% (gets to 100% sometimes) and I'm wondering? If when my beans arrive, and I'm ordering 1MT at a time, whether I should'nt just roast them all one time, winnow and hoard the nib. If so, what would be the the best way to hoard nib?

Any help, appreciated.... Thanks

[Sebastian]

Roasted nib will still pick up moisture. Why not control the environment to dehumidify? 1MT doesn't take up that much space.