How to: grow chocolate

Wherever we take travellers in the tropics, from Mexico to Singapore, the Daintree to Cuba, there is one tree that grabs their attention - cacao, the source of our lingering love, chocolate.

Theobroma cacao. Photo - Narong Khueankaew/Shutterstock.com

Cacao (Theobroma cacao) is a tropical tree crop that originated in the Amazon basin, where it grows in the shaded rainforest understory. In Mayan civilisation cacao was a vital part of religious ceremonies; in Aztec culture cacao beans were a form of currency and were also used to make a thick bitter drink. From South and Central America, cacao cultivation spread to the Caribbean and then across the Pacific to the Philippines, East Indies and India.

When a process for making milk chocolate was developed in late 18th century Switzerland, European consumption really took off and cacao is now an international commodity, grown in a narrow band around the equator. Think of Hawaii as the north pole of Chocolate Land and tropical Queensland as the South Pole.

Cacao on the tree. Photo by Puerto Vallarta Botanic Gardens

Growing

The tiny white starry flowers of cacao appear directly on the stem, a form of flowering called cauliflory. The flowers are pollinated by little midges that live in the thick rotting leaves on the floor of the rainforest. Cacao is dependent on the midges and on the mycorrhizal fungi living in the mulch that help provide nutrients to the plant.

Cacao harvest. Photo - Joseph Sorrentino Shutterstock

Heirlooms

This lifestyle is at odds with the neat and clean approach of most commercial farming, so cacao and commerce haven’t always seen eye to eye. Now heirloom cacao, like so many of our food crops, is threatened by commercial cultivars that provide more easily grown, higher-yield trees, albeit with less tasty pods. The growth of commercial cacao plantations is reducing cacao diversity and having a negative impact on indigenous wellbeing - as well diminishing the amazingly varied palate of flavours available to chocolate lovers.

Heirloom cacao farmers are fighting back, trying to preserve plants like Brazil’s very rare, blue-podded cacao; Ecuador's ancient national variety, ‘Arriba Nacional’; West Africa’s indigenous ‘Amelonado’; and Indonesia's sought-after ‘Java A Cacao’. (Zokoko, in Emu Plains, (www.zokoko.com.au) is the Australian chocolate maker listed on heirloom cacao sites as being committed to supporting heirloom growers.)

Harvest

The pod takes about six months to develop after pollination. It colours red or yellow as it ripens and holds inside it 30-40 seeds in a sweet pulp.

When the pods are harvested, the pulp and seeds are scooped out and piled together in baskets lined with banana leaves. The wild yeasts on the banana leaves helps ferment the beans, a process which starts the development of the unique chocolate flavours within the beans.

After the ferment the beans are dried slowly in the sun for about 10 days, which allows the volatile acids to dissipate. Once dry the cacao beans are stable and can be stored or shipped, before being roasted, ground, and conched into the treat we just can’t resist.