Can Cocoa Beans be TOO Fresh?

Sometimes fresh is not best - it's necessary to age cocoa beans before using them

I received the following email from a ChocolateLife member, who gave me permission to post it here:

Dear Clay:

I'm starting up a group of farmers in the north of Malawi, right next to Matema/Kyela in Tanzania.

We're getting beans from Tanzania that us giving a off flavour reminiscent of grass or a yeasty taste (not smell). The flavor is particularly pronounced in the cacao powder after roasting at 135° C for 20 minutes in a drum roaster. I'm grinding the beans as for chocolate liqueur, and pressing using a vehicle hydraulic jack and large truck cylinder.

Questions

  • Is this possible to remedy through roasting and conching?
  • Where do I start looking for the problem in the fermentation process?

The group we started only produce about 250kg of beans per week, but we'd like to build up a artisanal chocolate business aimed at tourism, if we can get the quality right.

Pierre

My response

Pierre:

To the best of my knowledge you may be able to process out the grassy notes in the chocolate by roasting and conching but you'd do that at the risk of processing out flavors and aromas you want to keep.

However - there may be a simple solution and it requires an answer to a simple question: How long is it from the time the beans come off the drying pad before they are roasted?

Believe it or not, "fresh" beans need to be aged before they can be used. There's not a whole lot of formal research on this because it's not an issue for most chocolate makers as it normally takes several months for the beans to reach the factory after leaving the farm. If you are roasting the beans within 8-12 weeks of their being removed from the drying pad there is a likelihood that you'll get the notes you're finding, along with yeasty and/or wet cardboard flavors.

I know that it costs to keep beans in inventory before using them, but I would cast about for beans that have been aged for at least 2-3 months before processing them to see if you have the same issues with aged beans.

I think it's great you're looking into a small-scale business that incorporates tourism and please keep TheChocolateLife community apprised of your progress!


I am looking forward to learning more.

Comments
No. 1-4
Sebastian
Sebastian

Hi Pierre - curious as to if you were ever able to try splitting a batch and roasting half under your normal conditions, and half at the elevated temperature noted earlier - and if that had any impact?

Sebastian
Sebastian

Hi Pierre - this wasn't immediately obvious to me (it could just be that as i'm aging technology is outpacing me...) - but my response is collapsed underneath your post, and may not be apparent that it's there. In fact, when i came back to the page after i posted, i had to do a double take to find the post that i knew i just posted, but couldn't find...

Pierre le Roux
Pierre le Roux

Hi Sebastian Great input. By grassiness, I refer to a "green" taste reminiscent of freshly mown lawn..the beans are processed very cleanly, no cross contamination, and were fermented for 7 days (low temperatures and rain in first couple of days required this) The fermentation was also - as en experiment - started off with inoculation with 10g packet of local bread yeast in a batch of 180kg of wet beans. Beans were fermented in 60 liter plastic bins, and stirred well every second day. On the 4 th day, temperatures reached 47°C (recorded with a HOBO datalogger), and when the temperatures kept dropping, the beans were first shade-dried fir 24 hrs from day 7, then moved to full sun. A nice dark reddish brown colour developed.

The beans were not showing any signs of mould or bacterial growth, and low acid smell compared to beans normally from groups in the region. After drying, and storing in plastic bin, acid smell (acetic) was more pronounced. A sample of 3kg (wet) was drawn at day 4.'

The grassy notes seems to be common to samples from the area this time of the year - of another 7 samples obtained, 6 showed the same "problem" - it does seem to decrease as the batch rests, and I will be keeping an eye on the process.

Ant other helpful suggestions, or comments?

Sebastian
Sebastian

Troubleshooting flavor from a distance is a VERY difficult thing to do, largely as a result of not having a shared lexicon (are you positive that what he means by grassy, you mean the same thing?)

There's a tremendous amount of research in this area - almost none of which is public i'm afraid. Grassiness as a function of bean processing (note: NOT as a result of cross contamination), absolutely can be processed out. If it's present as a result of cross contamination (ie be stored or coprocessed with other vegetal materials) - it becomes a bit more complex. Sometimes it can be processed out, sometimes it can't.

Out of curiosity, what makes you recommend aging of the dry beans as a solution to grassiness?