Friday is here, and the 'A Taste of Science for the Weekend' column is back — number 76.
This time: how banana leaves and bacteria are used to make chocolate, and a technology that may render cacao plantations obsolete.
-
The familiar, beloved chocolate we know is a far cry from the cacao fruit it comes from.
The fruit consists of a thick pod containing a pulp that holds several dozen seeds — cacao beans.
After the fruit is harvested, it is split open with a machete, and the beans along with the pulp are piled up for a lengthy fermentation process.
Fermentation breaks down the pulp, turning it into liquid that separates from the beans.
The beans then continue through the fermentation process, are dried, and sent to factories where they are separated into cacao solids and cacao butter.
These components are used to produce the cacao products we know — most notably chocolate, which is made from a mixture of cacao butter and cacao solids in varying ratios.
To understand what really happens throughout this process, let's break it down step by step.
-
The first stage of fermentation relies on yeast and an anaerobic — low-oxygen — environment.
The pile of pulp and beans is tightly covered with banana leaves.
Covering the pile with plastic has been found to be less effective, because banana leaves provide the perfect combination of yeast and bacteria needed for the process, along with a non-hermetic seal that prevents mold from forming.
The pulp is rich in sugar, and yeast uses sugar as an energy source, producing ethanol. This process causes the pulp to break down and raises the temperature of the mixture to an optimal level.
-
The second stage relies on bacteria that break down the ethanol produced in the first stage into acetic acid, releasing a large amount of energy as heat.
These bacteria are active in an oxygen-rich environment, so farmers turn the beans thoroughly to introduce plenty of oxygen into the mixture.
The acid and heat penetrate the core of each bean and kill the embryo, causing the cells to break down and turning all the components of the beans into a uniform mixture.
The beans are now ready for roasting, which will ultimately transform them into chocolate. They are dried and shipped to chocolate factories around the world, where they are roasted.
-
The cacao industry suffered from a global shortage and significant price increases throughout 2024.
Cacao grows only in the equatorial zone, takes many years to bear fruit, and various diseases and adverse weather conditions have substantially reduced yields.
Dependence on African countries for cacao cultivation compounds the problem — both because farming practices there are not advanced, and because there are allegations of exploitation of farmers who receive meager wages and of children working on plantations.
-
In recent years, attempts have been made to grow cacao in the laboratory from natural cacao samples.
The main challenge was producing cacao butter with a high fat content, but even that hurdle has recently been overcome.
Lab-grown cacao takes only a matter of days, with no risk from adverse weather and no need for a global supply chain.
Lab production is still expensive, but as the field develops, prices will fall and the need for natural cacao plantations will steadily diminish.
-
The insights from cacao research may have far-reaching implications when applied to the production of coffee and other important crops as well.
Research into cacao beans has also identified the factors that influence flavor, meaning that lab-produced chocolate will be especially delicious — with a precise taste designed in advance.
Another interesting area is the use of cacao husks — which account for roughly 70% of the fruit's weight — to produce fuel and bioplastics, which would contribute greatly to environmental sustainability.
Cacao is not only delicious; it is also particularly fascinating, and the more we study it, the greater the benefits it will bring us in ways we never anticipated.
Shabbat Shalom 😊
--
If you enjoyed this column, you're welcome to follow along and enjoy it again next week.
Video credit: Noal Farm
#ATasteOfScienceForTheWeekend