The Malting Process as it Relates to Cacao Fermentation

05/28/12 07:18:11PM
205 posts

I have read now in a few places that the best chocolate is made from fermented beans that were left in the pods for about 4 days after picking before then being opened and fermented. This got me thinking about an explanation, perhaps this is akin to the malting process. The malting process is where a grain is taken, most commonly barley, and it is soaked in water and then allowed to germinate. Once germinated it is then dried for a few days at around 50degC then roasted after that to the darkness required. The process of germination breaks down polysaccharides into monomeric sugars such as glucose and fructose and also proteins are broken down into amino acidsthese arethe two precursors for the Maillard reaction which is responsible for the flavours in chocolate.

So joining the two together is it possible that leaving the pods once cut for 4 days before opening and fermenting leads to changes in the beans akin to malting providing the bean with more precursors to the chocolate flavour? I know that cacao germinates very quicky, I am growing some in Darwin at my sister-in-laws house.

I had a quick look in the scientific lit. and couldnt find any refs on the subject, it would be a cool research project I think.

updated by @tom: 04/21/15 12:52:21PM
brian horsley
05/29/12 01:58:15PM
48 posts

Hi from Peru Tom, I can only speak to my personal experience with this in one place and two varieties of cacao, and without a serious grounding in the chemistry of it which you appear to have. i've done sample lots of pure nacional (with 40% white beans) and ccn51 leaving cut pods on the ground 1, 3 and 5 days before opening and beginning fermentation. the 1 day lots are not noticeably different from putting the beans in the fermenter the same day they are opened.

in 3 days, as you say many beans germinate. these have a slightly different aroma going into the fermenter, and they seem to ferment a little differently, and taste a little different once fermented, producing a problem with uniformity between the two classes of bean. also the germinated beans can have a problem with their skin sloughing off somewhat in the fermenter box and thus they are not well protected on the dryer bed and can get kind of burned and crumbly in the time it takes the other beans to dry.

at 5 days most of the beans have germinated and to me they have an off flavor, slightly putrid, that does not improve with fermenting. a matter of opinion obviously and my palate is not among the best so who knows?

a few logistical problems, at least here in my area with letting them sit -- the cacao parcel is not always right next to the farmer's house and if the pods are left lying there often someone will steal them. also a pile of pods is like a dessert tray to a squirrel or monkey, they get some % of pods on the tree but i have seen a sitting pile get ravaged almost 100% by critters. finally many consider a germinated bean defective, it has a telltale hole where the germ comes out and it can affect grading of the beans.

so for all those reasons we don't do it here, but in the right place at the right time, and taking logistical issues off the table, it might be a good option. i am attaching the one study i know of which addresses it, from portillo et al in venezuela, this is the english translation they published, its not perfect, if you want the original spanish let me know. they conclude that 0 days on the ground is best, but i think they only compared it to 5 days, not any intermediate value like 3 or 4. also they are talking only about criollo porcelana

good luck in darwin,


antonino allegra
05/29/12 06:08:50PM
143 posts

unfortunately, for me, i have no access to fresh pod!

but reading the comment from brian, and taking in consideration a bit of experience with wheat (beer) and germination, i would do it this way:

Remove the beans after the first day of picking, somehow wash them (to stop/slow down fermentation) let germinate in a even bed, then roast them directly. see the result.

i guess it could be one of those "add on" to your traditionally beans to create an extra/different flavor note...

I would be very curious to taste a chocolate made with 100% unfermented but malted beans... i might have just given a world discover away. !!!!

For you lucky people living in Cocoa farms: if you ever try my idea and it works:please, at least, send me a fly ticket to come and visit you ah ah aha !!!

05/29/12 06:33:27PM
49 posts


We have a standard practice of cutting pods and leaving them in a collected location for 4 days. I have found that the "resting" phase, through evaporation, reduces the amount of liquid that must be drained during fermentation and concentrates sugars contained in the fruit. We have had no germination experiences and find the fermentation temperatures rise substantially higher when the pods are opened 4 days after harvest. I don't know what the method of collecting after cut is being used in other locations but we have developed a tool for picking ip pods without using sharp tools. Many locations use machete or other to "stick" the pod then enter to the transport basket. BAD PRACTICE....once the pod interior has been introduced to oxygen, fermentation begins and there's no way you can expect to get a controlled fermentation cycle. We have found the most significant steps in our process are:

1. collect only fruit that is fully ripened. There are economic reasons to collect all ripe, near ripe and promising to ripen pods when the harvest is made. This precludes having to return the next week for an additional cutting.

2. move beans to fermentation boxes within 8 hours of opening the pods. Do not co-mingle "good" beans with diseased, discolored or otherwise non-standard quality.

3. utilize fermentation boxes that have free flow for allowing liquids to exit the fermentation unit. Our fermentation boxes are constructed with 5mm gaps at all joining surfaces.

4. maintain a cover over the fermenting beans to retain heat. I am against the use of banana leaves as cover as the collect humidity on the surface adjacent to the bean and "rain" on the pile when cooled temperatures are encountered at night. We use fabric material which can be washed after the fermentation cycles terminate.

5. The remaining steps are a function of bean temperature, ambient temperature, sugar concentration, heap size, and must be measured at daily intervals with adjustments as required. Final phases of fermentation must be carefully managed to produce full fermentation without excessive fermentation. We use pile temperature to manage the first phases and bean cuts for concluding when beans are ready to dry.

Item 1 and Item 5 are absolutely required for quality fermentation...the other items may have a small impact on the final product but omission of 1 and 5 are guaranteed disaster.

Jim Lucas

Fazenda Venturosa

Floresta Azul, Bahia, Brazil

05/29/12 09:53:23PM
205 posts

Thanks for the responses guys, that has been very insightful!

So Brian, would you say that leaving the pods for the one day period gave you the best flavour in the finished chocolate, you mention it is noticably different from doing it asap.

I might try and get my mate in FNQ who grows to try leaving the cut pods for a day or so and see the effect on the chocolate.

My little cocoa babies in Darwin are going great guns, only about 2 more years and we might see some flowers.

Seneca Klassen
05/31/12 03:02:17AM
17 posts

It may be that I'm misunderstanding, but I wanted to clarify that germinated cotyledons should *not* be included in ferments...these will inevitably result in faulty outcomes, and should be discarded. Jim's comments make sense to me--it's useful to experiment with holding pods (or wet seed, for that matter) before beginning a ferment, but germinants are a sign of substantial overripeness, and definitely not a positive.

As far as the issue of malting, I think there are substantial enough botanical differences between seeds and cotyledons that there's probably no useful parallel. See Wood & Lass, Hardy and Knapp for solid analysis of the various processes occurring during fermentation and their effect on flavor precursors.

05/31/12 05:07:48AM
205 posts
Seneca, I was meaning that during the time between cutting a perfectly ripe pod from the tree and the opening of that pod the seeds may undergo chemical changes similar to that of the malting process as they move towards germination. I am certainly not advocating germinating seeds before fermentation. Just looking for an explanation as to why leaving the cut pods for a few days before opening and fermenting results in beans that ultimately give better chocolate, as attested to by Jim and Adeir Boida de Andrade.
05/31/12 05:43:40PM
75 posts

I don't think we have to turn to malting as an explanation. It's basically a drying out of the pulp as Jim said, which probablyreduces the anaerobic yeast stage of the fermentation with air gaps opening up in the beans faster. This would lead to a faster take over of the aerobic bacteria and a faster heating of the pile.

I think it can have a lot to do with the variety, as thin-walled Criollo may dry out too fast and no longer be good for a ferment, whereas the other varieties can benefit from sitting for a bit.

I agree with Seneca that grains have sugary starchy endosperm as the majority of their seed, whereas the cotelydons that make up the majority of cacao seeds do not have all these stored sugars, one of the reasons they have to be planted within a week of harvest and can't stored to keep them viable like grains. This is true of many tropical seeds that depend on germinating very quickly and not survivingthrough a winter with the stored sugars before having proper conditions to germinate. Without those stored sugars, there's nothing to malt!

Thanks for stimulating the interesting discussion, Tom! This aspect of fermentation needs to be talked about more.



Nat Bletter, PhD

Chocolate Flavormeister

Madre Chocolate

05/31/12 06:56:44PM
205 posts

Thanks for the explanation Nat. I agree this is not part of fermentation that I have heard much about and it is interesting as it may help some of the growers I know make better chocolate.

brian horsley
06/12/12 12:26:28PM
48 posts

Hi tom i was in campo and offline for some time there. sorry for the delay. I said that the 1 day rest period did NOT produce a noticeable difference, they were indistinguishable flavor-wise from beans taken out of the pods the same day as harvest which is our normal procedure.


Robert Graham Erdman
06/19/12 03:31:35PM
1 posts

I've brewed beer for many years. The malting process as you mentioned, does break things down, though I think its primarily starches (the endosperm's energy supply storage) into sugars useable by the barley seedling. It's essential to kill it, (kilning) to interrupt the sprouting process. This might be akin to the patio drying taking place in cacao processing. In barley production, its done in gas rotary kilns. Malting and kilning does have dramatic impact on the barley's flavor profile, it's diastatic power (the sugar-to-alcohol conversation) and ultimately the beer's flavor.

I know nothing about cacao, though I'm absorbing info like a sponge... But your intuition is probably spot-on, as Aussie's might say. Experiments were probably done by big chocolate co's over the past century, though those may be trade secrets. As the folks at Xoco point out, the drying/fermenting process by small farmers nowadays is probably hit or miss.

I'd do a controlled experiment at your in-laws house. Take a pod or two and wrap them in damp newspaper or muslin, take some other pods and remove the seeds, then wrap the seeds in damp paper, etc, with a control group with no fermenting at all. Dry each batch under the same dessicating conditions and then roast, grind and process. Do a taste test, varying ferment times and temp.

Would be cool to try this at home, but alas no cacao in Atlanta, GA usa.



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