From farmer to chocolate maker, every actor in the cacao supply chain has to deal with humidity. Humidity comes in many forms and shapes: rain, moisture, dew, pulp, evaporation, and much more. Whatever form it has, humidity can have an impact on the quality of cacao and thereby on chocolate. Time to take a closer look at humidity as a cross-cutting theme in the cacao supply chain.

Cacao trees originate from the tropical forests of South America, where they grow under the canopy of neighbouring trees. With this heritage, it comes as no surprise that cacao tree seedlings love a warm and humid environment, and cannot stand direct sunlight. Without cover cacao tree seedlings die very quickly. Smaller trees are often planted close to banana trees that give the growing cacao seedlings the much-needed shade. Once taller, cacao trees can better deal with the sun, but also need shade and always prefer a humid environment.

The ideal climate for cacao trees is warm and humid, which can be found in the tropics. Cacao trees need around 1500 to 2000 mm of rain per year, but – as they are not easy to please – they like the rain to be evenly spread throughout the year. Under these circumstances cacao trees will grow pods almost the whole year, just like their ancestors in the tropical forests of South America.

Prolonged dry periods are not good for cacao trees. Their root system is mainly in the topsoil, so it is hard for the trees to reach water in lower soil layers. After two or three months without rainfall the trees will start to perish.

Question: why is the cacao harvest around 6 months after the rainy season? This is because the trees need rain to start flowering. And these little cacao tree flowers need around 6 months to mature. Lots of rain is good for the flowering, and lots of flowers are good for the cacao harvest.

A question related to this subject is why some countries have a high peak cacao harvest once a year, and much smaller fly crop in another season. This also has to do with rainfall: countries with one dominant rainy season will have a peak harvest season six months after the rains. The fly crop will be smaller, the beans might even be smaller, simply because their was little rain, and less flowering. West-African countries are known for a climate with a big rainy season and hot and dry weather in the rest of the year, and therefore the cacao harvest in West Africa peaks once a year.

The cacao flavour profiles of the main harvest and the fly crop can differ. Not better or worse, just different. That makes cacao even more interesting to work with!

Taking into account the climatic conditions preferred by cacao trees, it doesn’t come as a surprise that cacao is cultivated in a band of 20 degrees on either side of the equator, the so-called cacao belt. The downside of this region is that it is also prone to tropical storms. Cacao trees don’t like wind that much, and they definitely don’t like tropical storms. That’s why you’ll find cacao farms in places a bit more inland, in a protected valley, or behind a mountain ridge.

Agroforestry, in which cacao trees are intercropped with other trees and plants, is the best system for cacao. An agroforestry environment resembles the original habitat of cacao trees, it makes them less vulnerable for diseases, and it provides more pollinators. With regard to humidity, agroforestry is also much better for cacao trees than monoculture plantations, as it provides cacao trees with a good balance between shadow, sun, and humidity. Too humid increases the chance on diseases; too much sun (and thus too dry) is bad for the development of the pods.

Temperature, acidity, microorganisms, number of turns, pulp around the beans, fermentation boxes, and so many more parameters have an impact on fermentation, it doesn’t make sense to focus on humidity – even though this also has an impact on fermentation.

However, we can say that fermenting beans should be protected from the rain. Smallholder farmers, who ferment cacao on their farm, often use banana leaves to cover the fermenting cacao. With centralised post-harvesting of cacao, the fermentation unit needs to be covered by a roof or shelter to keep rainfall out of the boxes.

Stay tuned for the impact of humidity on drying, packaging, storing, sailing and transport!