To get into the details of what's going on with your setup will take some time i'm afraid.  If you're able to post a series of pictures showing the empty boxes (internal and external), as well as a shot of the whole setup from 10-20 meters back at 10 am, noon, and 4pm on a sunny day that'd be helpful.  The details are important here - where are you, what is the starting brix, how are you measuring temperature, how are you turning the beans, what is the external temperature graphed over a 72 hour period, etc all are important places to help start looking at..

@sebastian - can you point to some of those manuals or give some quick word on how box design impacts fermentation? Deeper is more acidic?

I'm doing some experimenting at ~400kg batch level, changing every 2 days across 3-4 boxes (~ 32" wide x 35" long x 35" tall), drainage holes on the bottom, banana leaves and jute sack on top. We're finding some temperature/fermentation inconsistency within this set of boxes -- by 96hrs there was still some pockets of cool fresh cocoa on bottom and corners. Could this be because box is too deep or cocoa too wet at start?

Our cocoa is quite wet compared to other areas i've seen. My best guesses are (a) add more drainage holes in beginning boxes (b) make the first box change at 24hr instead of 48 (c) mix in between box changes (d) make a more shallow box with less cocoa touching the wood. Looking for any tips you can offer though..

Note that when i mention consistency, i'm referring to wildly different each and every time; not so much exactly the same each time (which is almost impossible). It has less to do with size (remember that even the largest chocolate companies in the world rely on, by and large, individual farmers fermenting, which by definition is small scale). Small fermentations will vary considerably in moisture, fat, flavor, etc profiles i'm afraid.

look forward to hearing how it goes.

Thank you Sebastian,

I can't believe you take so much time and effort to help we the ignorant. I think you nailed it when you said: "i've seen instances where repeatability and consistently simply don't matter for local usage".

I think we'll try to make an excellent product but probably will not try for ultra consistency. In my years in the Specialty Coffee business, I shunned "consistency" speaking that it retarded perfection. If you CAN make a better coffee, don't beat it up by trying to be "consistent".

I'm way too old to bethinking about being "Big". Just want to make a nice product and have fun.

I, ever so greatly appreciate your; "over the top" help in trying to make some nice chocolate in a small way. I hope not to get big!!

I'll try to let you know how the fermentation goes.

Kindly, Jim

Hi Jim - i've actually written many of the manuals on cocoa fermentation, and while i may or may not be familiar with the specific one you're referencing, i will say that - generally speaking - the ministry of agriculture and rural development in Vietnam simply doesn't possess the technical acumen or depth of expertise when it comes to cocoa processing. They're improving, and i've worked there for many years to help them along. but they're not there yet.

generally speaking, small fermentations are not consistent or repeatable. They are difficult to scale. yes, i know people do it - but that does not mean they do so repeatably nor consistently. in almost every instance where someone swears they have a small repeatable and consistent fermentation, they have no frame of reference against which to compare a truly consistent and repeatable fermentation against (i.e. they *think* it works because it's the only thing they know). and heck, perhaps it actually does work for whatever local use they're pursuing - i've seen instances where repeatability and consistently simply don't matter for local usage.

In Hawaii, Dole has a plantation (mike conway manages it), where smaller fermentations were developed under the assistance of Guittard. they ferment in wood containers a few hundred lbs at a time, with drainage, just under a week.

Recently there has been a bit of patent activity (and will be more to come) on micro fermentations (very small mass fermentations) that are consistent and repeatable, as there's huge scale advantage should that be successful. we're quickly closing those technical hurdles, but to date they require some laboratory equipment to facilitate them, and certainly aren't viable in the field.

With small amounts, I remove about half of the 'mass' by pouring into an empty bucket. The 'mass' left in the box is placed in another.

The 1st portion is now replaced and the second placed on top.

Similar to cascading into another box.

I have used this many times with very small amounts, especially for experimenting with single varieties.

Hello Sebastian,

Sorry, I meant 12x12x12 which has a volume of 7.5 gallons. My current box is approx 16x20x8 which is about 11 gallons and was only about three inches filled (4 gallons). I wonder if anyone has a copy of the Vietnam manual for cacao preparation, they had all the measurements but it is off line now???

Hello Melonie,

Do you have any specifics on how you go about the fermenting process in small batches?? Do you use boxes or another method? Thank you for your help.

Here in Hawaii we often have small ferments

12" cubed? that'll only give you 2-3kg (ish) of beans. You're going the wrong direction i'm afraid.

Thank you both for your help. I'll try a 12 inch cube and see how it works next time. Any other suggestions would be appreciated.

Kindly

I do not believe that at that box size and fill level, you will achieve steady state. your surface area to internal mass ratio is just too high, and it won't be able to retain the heat it's generating. it can be very difficult to extrapolate very small bean fermentations (which are tough to do) to larger sizes - it doesn't scale linearly (i.e. if you get results your happy with at a 15kg bean mass in a little box - fermenting 300kg in a big box isn't likely to give you similar results)

Hello Cameron. In Trinidad and Tobago we ferment in 3' cubed boxes 3' High x3' wide x 3' high. We stack boxes 3 high in a 'cascade' system.

Although you may have a 'critical mass', [just the minimum to begin fermentation], the 'mass' needs to be stacked a little higher. At about 24'' [twenty four inches]. Maybe you can build a smaller box for smaller amounts.

A box with 'holes' may not suffice the 'runoff' of water etc. Try for 1 inch slats at a 1/4 inch spacing.

Fermenting for us takes place over 7 days, 1 day in box one, three in box two and three.

Take a look at Tobago Cocoa Farmers Association on facebook, I think there are pictures of us building boxes on the wall.

Good luck.

Thank you Sebastian: I am at sea level 8.5 degrees off the equator. I am trying to do a six day fermentation of freshly removed from the pod beans getting their temp to the 45 - 60 degrees C at about the forth day. I remember the boxes in the missing article were smaller and deeper than the one I made. I am also only doing smaller batches (15 Kilos or so) at least while I experiment and get started. I am looking to produce a dark chocolate and make it into 1 oz bars. This is the plan but I am light on my feet with all of it. My current box is about 16 X 20 X 8 there is about 3 - 4 inches of the beans in the bottom. Again, thank you for your help.

Again, thank you

There is no 'right' answer. it all depends on what it is you're trying to accomplish, what profile you're after. personally, i do no advocate field fermentations < 150kg if you're looking for consistency. Mine were often 300-600kg. Where are you fermenting, dak lak? if you're up at that elevation, your challenges will be compounded by how cool it gets at night..

OK, I am a newby FNG you might say. I am almost done fermenting my first approximately 15 kilos of beans. They did not reach the 45 degrees C suggested (Highest temp so far 34.6 degrees C). I just whipped up a fermentation box with holes in the bottom, banana leaves perf on bottom and on all sides. I had a web sight with the correct size to make the fermentation boxes (a manual from Viet Nam on cocoa processing) but it is off the internet now. Does anyone know the correct size to make boxes for fermentation? I think for 25 kilos would be what I need....or less.