January 16, 2020, by Lexi Earl
Doing science in the field: stories from our Colombian cocoa project
Dr Christopher Moore and Dr David Gopaulchan travelled to Colombia together in May 2019 to carry out scientific sampling of the cocoa fermentation process on different farms. David recently travelled back to Colombia for the second harvest, to conduct further sampling, in November and December 2019. We spoke to David and Chris about the experiences, and the challenges of doing science in the field.
Tell me about your first impressions of Colombia?
Chris: I had never been to South America before so it was all quite new. I think when you go anywhere new, you are always a bit cautious but all the people were incredibly friendly and you felt very welcomed, both on the individual farms but also in the cities.
David: I felt the same way because I didn’t know what to expect. However, during the trips most people did their best to help us, such as taxi drivers and even the average person on the street. Even though we couldn’t speak their native language, Spanish, if they spoke a bit of English, they would try to chat with us and if they didn’t know English, they used their phones and used Google translate!
Tell me about the first trip…
Chris: We had a few days in Bogota to recover from the flights and then we flew out to Neiva, which would be our base for the next week. There we were met by Raphael who was the head of FEDECACAO for the region. Everyday he drove us up to Carmen’s farm in his own car, up this dirt track mountain road. It was a two-hour journey there and a two-hour journey back. However, we always stopped off half way in the square at Palermo for a quick coffee, and to meet up with Armando (a FEDECACAO technician), who would also accompany us to the farm. From Palermo onwards, the road deteriorated, but the scenery was amazing. It was mainly forested mountain sides shrouded in wispy clouds. Every now and then you would pass a small farm where they would be growing cocoa, coffee or fruits.
What were your first impressions of Carmen’s farm?
David: When we got to the estate, we were surrounded by towering mountains with lush, green vegetation all around. In the distance there was a little, rustic house where Carmen and her family stayed. We had to walk about 10 minutes to get to the house, which included hopping over some rocks to cross a small stream and a short climb up a hill. We were first greeted by the family’s large, but very friendly dog ‘Bruno’ which became the morning routine for the rest of the trip.
Chris: Carmen and her family were very welcoming. On our arrival we were told that we were having breakfast and inside the house there was food laid out.
David: Every day they offered us either breakfast, lunch or both, as well as a lot of coffee.
Chris: Also delicious handmade hot cocoa!
Tell me about what you were doing on the farms
David: When we got there, Carmen’s partner (Victor) and his workers, were cracking cocoa pods, and collecting the beans to fill the fermentation boxes. So, we used this time to explore the farm. We documented the different varieties of cocoa they cultivated; that is something we are also interested in because depending on the varieties grown, you can have differences in flavours. We also collected swab samples of microbes on the farm.
Chris: We took microbial samples from the leaves, the pods, the surrounding soil, trying to understand where the microbes in the fermentation were coming from and how they vary between the farms.
Most importantly we also collected microbial samples of the fermenting beans over five days. In addition to the microbial samples, we also took the daily pH and temperature measurements of the fermenting beans to monitor the progress of the fermentation.
David: Furthermore, we assessed the beans using the cut test method, which involves cutting several beans and recording the degree of fissuring within their structure. The more fissuring there is, the further along the fermentation.
Chris: Both Carmen and Victor were really interested in the work we were doing and were keen to learn. So, we showed them all the things we were doing and they wanted to have a go.
Had you ever done any of that on-farm work before?
David: I had.
Chris: I hadn’t. When I was doing my degree, I always thought I’d end up doing ecology and working out in the field but in the end I chose a different path, so it was really interesting to be doing field work. I hadn’t seen a cocoa tree before this trip: so it was great to see the trees, the pods and the beans. I even got a chance to try some of the raw pulp. It was sweet but also quite acidic. I really liked it, but it tasted nothing like chocolate.
From Carmen’s where did you go next?
David: After collecting the samples at Carmen’s farm, we flew back to Bogota and then to Bucaramanga, a large city in the north. From there we took a car to Rionegro, where Martha’s farm was located.
Chris: Martha’s farm was much bigger than Carmen’s. They had higher production and had different crops – there were avocados, bananas, and citrus as well as the cocoa. Their fermentation setup was bigger too. It was a purpose-built room with fermentation boxes. Martha was not living on the farm, but she had a farm manager who oversaw the day to day running of the farm. However, Martha had an apartment on the farm, which she kindly let us stay in while we were carrying out the sampling. It was an amazing opportunity to stay in a beautiful location. During our stay at the farm we also had a visit from Hugo Olarte from CasaLuker (a chocolate company in Colombia and a collaborator on the project). He was very knowledgeable about cocoa production in the region and Colombia in general.
David: We also visited the FEDECACAO office in Rionegro. They showed us their warehouse with bags and bags of cocoa beans. The beans were bought from farmers in Rionegro and stored there before being sent to larger storage facilities and eventually to buyers.
Is it only the fermentation that affects the beans or are there other factors in play?
David: Fermentation plays a big part but the drying is also important.
Chris: They do test the moisture content of the beans on the farm while they dry, because too much moisture makes them likely to rot.
David: I think they aim for 7% moisture. That is a quality control step.
Chris: The different farms also have different varieties of cocoa which David was looking at because some are better for flavour and others are good cash crops where you produce a lot more.
David: Usually pale coloured beans indicate better quality flavour.
How do you prepare for these trips?
Chris: It is quite difficult because you have to plan all the experiments in advance, and ask yourself what exactly would I need? Then you make sure to ship the items to the location and/or take it with you. If you don’t, you can’t just pop into a store or a neighbouring lab and go, “oh I need a few more of these”. So we have to plan exactly how much of everything each experiment takes. It is tricky and a bit nerve wracking as well because we don’t want to be out there and run out of anything. It is not a trivial thing to do. In a trip in August, we sequenced the DNA from the microbial samples at CaserLuker in Bogota. However, in November last year (2019) we did our first on-farm DNA sequencing of the microbes involved in fermenting the cocoa beans. This proved to us that it was feasible to use this technology to monitor cocoa fermentations in real time in the field.