Cocoa

Overview

Cocoa, Theobroma cacao, is a small evergreen tree that grows 4-8 metres in height and is native to the deep tropical regions of Central and South America. In its natural habitat, cocoa is an understorey species and related to cotton and okra. Its seeds or beans are processed to make cocoa mass (liquor), powder, cocoa butter (used as an ingredient in the food and cosmetic industries), paste and chocolate. The husks and fibres that remain after processing are used for animal feed and fertiliser.

A new cocoa industry is in operation in far north Queensland, growing plants from hybrid seed imported from Papua New Guinea. Boutique markets are under development using the concept of high quality ‘origin’ chocolate and there is potential for chocolate-based tourism built around a ‘bean to bar’ concept.

Growing cocoa as a plantation species is challenging and the cocoa industry is addressing fundamental issues of cultivation and processing. Establishment of seedlings is challenging and the trees are prone to cyclone damage, but research is underway to investigate solutions for these problems. The establishment of the industry will be greatly helped by the development of a successful method of processing of Australian grown beans, which involves mechanised pod splitting and extraction, fermentation and drying of the beans. The economic viability of Australian-based cocoa production will be reliant on good prices and high productivity of harvesting and processing.

Facts and figures

Cocoa is a small (4–8 metres) evergreen tree, native to the deep tropical regions of Central and South America
Establishment of cocoa is challenging as the plant is particularly sensitive to wind, high light levels and moisture stress
Beans from the cocoa plant are used to make cocoa mass (liquor), powder, cocoa butter, paste and chocolate
The cocoa industry is a new industry in Australia and as at 2013 there were around 20 hectares of cocoa in production
Potential industry development in Australia lies in the development of an ‘origin’ based boutique chocolate industry and tourism opportunities such as ‘bean to bar’

Production status

In 2011–12, worldwide production of cocoa was approximately four million tonnes, valued at US$2307 per tonne, and over 70% of production was in Africa. Around the world, 90% of cocoa production is on landholdings of 4.8 hectares or less; and 5% comes from plantations of 40 hectares or more.

The cocoa industry in Australia is new, with only 15 to 20 hectares under production. An eight-year feasibility study showed that the best cocoa production in Australia was at Mossman, 100 kilometres north of Cairns. New plantings are also being established in the Innisfail region using trellis management. There is potential for an industry to encompass 1,000 hectares, producing up to 3,000 tonnes of dried bean. The value of raw product to the region would be around AU$10–12 million.

Map of current and potential growing regions

Uses

Cocoa bean is used to produce cocoa mass (liquor), powder, cocoa butter, paste and chocolate, with the main product being chocolate. The cocoa beans are contained in a pulp within the pod, and in some countries the pulp is used to prepare a refreshing juice. Each seed contains a significant amount of fat (40–50%) as cocoa butter.

The most noted active constituent in cocoa beans is theobromine, a compound similar to caffeine, which is a mild stimulant and the chemical responsible for the well-documented enjoyment of chocolate.

The extraction of beans from the pod leads to by-products of husk and fibre, which are used as animal feed and fertiliser.

Production Requirements

Growing regions

Cocoa trees grow well in humid tropical climates and globally the bulk of cocoa is grown within 10^o either side of the equator with some production areas extending to 20^o of the equator.

The wet tropical coast of northern Queensland, from Cardwell to the Daintree (15-18^oS), although not classically tropical, is environmentally suited to cocoa production. High yields of up to three tonnes per hectare of dry beans can be achieved with the beans meeting commercial requirements of size and physical and chemical characteristics. The natural environment of the cocoa tree is in the Amazon forest and whilst cocoa has evolved as an understorey plant, it can be grown in full sun but requires irrigation and fertiliser management to do so successfully. Cocoa trees require careful management, especially during the first two years of establishment.

Soil type

Cocoa is grown in a wide variety of soil types around the world. Information regarding appropriate soil types for cocoa production is available from the International Cocoa Organization. Generally, the cocoa plant needs a reasonably fertile and coarse-textured soil, to a depth of 1.5 metres to allow a good root system to develop. Cocoa will withstand waterlogging for short periods, however it is important that there is no impermeable material below the root zone that prevents excess water draining away. The cocoa tree is sensitive to a lack of water, so the soil must have both good water holding capacity as well as good drainage.

The correct chemical properties of the topsoil are critical, as the cocoa plant has many surface roots for absorbing nutrients. Cocoa can grow in soils with a pH ₍_water₎ of 5.0–7.5 but excessive acidity (pH 4.0 and below) or alkalinity (pH 8.0 and above) must be avoided. Cocoa can be tolerant of acid soils, provided the nutrient content is high enough. The soil should also have a high content of organic matter (3.5% or more) in the top 15 centimetres of the soil.

Climate

The cocoa plant is adapted to tropical climates and responds well to relatively high temperatures, with a maximum annual average of 30–32°Celsius and a minimum average of 18–21°Celsius.

Annual rainfall between 1,500 and 2,000 millimetres is generally preferred. Dry spells, where rainfall is less than 100 millimetres per month, should not exceed three months, as cocoa trees are very sensitive to a soil water deficiency. The International Cocoa Organization states that the variation in yield of cocoa trees from year to year is affected more by rainfall than any other climatic factor.

A hot and humid atmosphere is essential for the optimum development of cocoa trees. In cocoa producing countries, relative humidity is generally high: often as much as 100% during the day, falling to 70–80% during the night.

Cocoa trees do not cope well with wind , growing trees in protected pockets or the judicious use of wind breaks are an important aspect of management.

Varieties

New and existing cocoa producers need to ensure they use only high-yielding hybrid or clonal material for the establishment of plantations. Hybrid lines are known to bear pods earlier and achieve higher yields. Clonal lines may achieve higher and more stable yields but these are yet to be tested rigorously in Australian conditions.

An Australian cocoa feasibility study (2010) evaluated the performance of five hybrid seed lines imported from the Cocoa and Coconut Research Institute (CCRI) in Papua New Guinea (PNG). The hybrid introductions were all based on the SG2 hybrids which are commonly grown in PNG. The hybrid lines were selected on vigour and based on crosses with 10 different cocoa lines with Upper Amazonian and Trinitario origin. The best of the hybrid lines produced 2.7 tonnes per hectare of beans at Mossman in far north Queensland.

Clonal material of cocoa plants from the University of Reading (United Kingdom) was brought in for the feasibility study. The clones consisted mainly of Forastero material with one clone being of Trinitario origin. The eleven clones were considered to have a good mix of quality, yield and disease resistance characteristics, however they were not evaluated extensively under Australian conditions.

More high-yielding cocoa material needs to be sourced and evaluated in Australian conditions to assist in the development of a viable industry.

Planting and crop management

In Australia, a plantation design is important to ensure efficient layout of irrigation and to enable vehicle access for management and harvest.

Cocoa plantations in Australia require a high level of management to establish successfully, starting with the planting of nursery-raised seedlings and close monitoring of the plants throughout the establishment phase. The optimal planting design for an Australian cocoa plantation is still being determined, with current field evaluations of planting densities, including double and single rows.

While established cocoa can grow in full sun, shading is indispensable in a cocoa tree’s early years. Also critical are excellent wind protection and precise management of irrigation, nutrients and pest and disease problems, particularly in the first two years of establishment.

Management of cocoa plantations in Australian conditions is still being refined. The experiences of pilot growers in northern Queensland are documented in the publication Commercialising cocoa growing in North Queensland.

Weeds, pests and diseases

Weeds present a challenge to the establishment of a cocoa plantation, particularly in the early stages when cocoa seedlings are small. Competition with weeds must be reduced and this may require spot spraying for grass and broad-leaved weeds.

Although no major diseases established in cocoa trials undertaken in northern Queensland, some of the pests and diseases that could be found on cocoa during the feasibility study included:

termites (Mastotermes darwiniensis) – Darwin
longicorn beetles (Acalolepta mixtus)
fluted scale (Icerya spp.)
red banded thrips (Selenothrips rubrocinctus)
aphids and mites
swarming beetles (Monolepta australis)
fruits potting bug (Amblypeltalutescens lutescens) was a minor pest
tree rats
anthracnose was occasionally sighted
brown fruit rots, which established if pods were left on the trees for too long.

Cocoa plants should be regularly monitored for pests and diseases, and spot spraying or broadacre spraying should be undertaken with appropriate and registered pesticides when the pest or disease reaches an identified threshold level. As there are no registered or permitted pesticides for use in cocoa in Australia, another challenge for the industry is to gain access to additional pesticides registered for use on cocoa pests and diseases. Further information should be sought from local departments of agriculture. Detailed information on cocoa pests and diseases found in Australia can be obtained from the publication Producing Cocoa in Northern Australia.

Infrastructure Requirements

Cocoa production in Australia will require vehicles and implements for maintenance of the plantation and an irrigation system. These requirements may be already in use or potentially shared with other enterprises on the property. Specific to the cocoa enterprise, tools for harvest such a secateurs and poles, and field bins and trailers will be needed. Capital requirements for establishing a cocoa plantation are set out in the report Commercialising cocoa growing in North Queensland.

Harvesting & Processing

Harvesting of cocoa beans is problematic as the pods ripen in cycles, with peaks and troughs throughout the year. The pods also vary in size and do not drop from the trees when ripe. Pods to be harvested must be individually selected and handpicked, and the task is made more laborious and time consuming because the pods are concealed within the thick canopy of the tree. The need to manually harvest is one of the impediments to the development of the industry in Australia and as at 2013 there were no mechanical harvesting options available or in development.

The design of cocoa plantations must enable vehicle access into the plantation to bring in equipment or machinery that will aid harvest. Various forms of harvesting aids have been explored for cocoa in Australia, and these may include trailed or self-propelled catching frames and/or gantries that direct harvested pods to bulk storage bins. Australian research has also developed mechanical splitting and separating technologies for the cocoa beans. In traditional cocoa growing regions, after being cut from the tree, the hand-harvested pods are split open and the beans scooped out by hand. This Australian research provides a significant reduction in manual labour.

Pod processing, fermentation and drying are essential steps in converting cocoa pods into the foundation material “dry beans” for chocolate making. In most traditional cocoa producing countries, harvested cocoa pods are processed into dried, fermented beans on farm. This ‘primary processing’ of cocoa involves three steps:

opening of the cocoa pods and extraction of the wet bean
fermentation of wet beans
drying of fermented beans.

Fermentation methods vary considerably from simple in-field heap fermentations with beans wrapped in banana leaves, through to industrial scale, central cascade box fermentaries servicing large production areas. Depending on the method utilised, fermentation takes five to seven days.

Bean drying is started as soon as fermentation is completed. Drying technology varies from simple sun drying, solar-assisted drying to large-scale dryers using forced hot-air facilities. Sun drying takes over a week, whereas artificial drying can be achieved in as little as 48 hours.

Fermentation and drying are crucial to developing cocoa quality and small variations in the technique can have a major influence on flavour development. More importantly, for a small industry, the process has to be repeatable as there is no opportunity to blend beans as occurs in the production of commodity cocoa.

Australian research has resulted in the development of a successful fermentation and drying regime, which is suited to the wet tropics of far north Queensland.

Risks and Regulations

One of the significant production risks in the areas suitable for cocoa production in Australia is the incidence and impact of devastating cyclones. Research work has been initiated in the development of ‘cyclonic resilience’ of cocoa plants with trellising and emergency defoliation of plants two to three days prior to the forecast impact of a severe cyclone. Cuttings of windbreak plant species such as wiliwili (Erythrina variegata sp.) are also being trialled.

Currently the main challenge to the further development of the cocoa industry in Australia lies with successful establishment of facilities for pod and bean processing. Optimum economic benefit is dependent on the production of consistent high quality dried bean, therefore refining the fermentation process for Australian grown cocoa beans is a priority.

Regulatory considerations

Quarantine restrictions exist for the importation of cocoa seeds and plants into Australia. Details about importing plant materials are found on the website of the Federal Government’s Department of Agriculture.

Theobroma cacao

Resources

Wood, G.A.R. and Lass, R.A. (1985). Cocoa. Fourth edition, Longmans, London.

Beckett, S.T. (1999). Industrial chocolate manufacture and Use. Blackwell Science Ltd. UK.

Bittenbender, H.C and Kling, E. (2009). Making chocolate from scratch. University of Hawaii, Cooperative Extension Services, Food Safety and Technology Bulletin FST-33.