Cocoa grows on tree some 20 metres high in the wild and 3-8 metres under cultivation in parts of the world close to the Equator - 20° north and 20° south. Largest producers are Ivory Coast, Ghana, Indonesia, Brazil etc.
The three main varieties of cocoa beans are:
Criollo - 'Native' or 'of local origin' Grown in Central America and a few regions of Asia. Probably originally from Mexico. Now represents only about 5% of the world's production. Very high quality. Very aromatic, substantially lacking in bitterness. Used in the best quality chocolate but rarely alone because it is scarce and very expensive. It is finicky to grow and doesn’t like adapting to different climates.
Forastero - 'Foreigner' or 'stranger' Originally from the Amazon. Ordinary everyday cocoa. Represents 80% of the world's cocoa. It has slightly bitter flavour and is sometimes called in coffee terms as 'cocoa's robusta beans'. Everyday chocolate.
Trintario - developed as hybrid of above 2 on Trinidad as a result of the near total destruction of the Criollo plantations by a hurricane in 1727. Seeds for new plantings were brought from Venezuela and cross-fertilised. Resulting hybrids have characteristics of both Forastero and Criollo. Represents about 10-15% of the world's total cocoa beans. Trinitario makes fine chocolate. Its blends are fine and rich in fats.
The flavours of all these beans are affected by the location, climate and soil in which they are grown.
Cocoa trees have tiny delicate flowers from which pods hang from trunk.
Pods - like rugby balls - grow directly from the lower branches and the trunk. They contain between 25 - 40 seeds which are the size of olives and formed like a giant corn on the cob. The pods weigh between 200-800g and ripen after 5-6 months.
The taste of the freshly picked beans resembles sweet milky lychees, pineapple. After a few hours they become very bitter and inedible.
One tree produces only enough beans for 1kg chocolate per year.
The pods are harvested and smashed open with a machete, they then lie cut open to ferment and dry in the sun. The seeds are scooped out and left to dry in the sun before being shipped and transported.
For most commercial chocolate beans are blended with beans from different countries according to each manufacturer's recipe. The exception is for Origin or Single Bean Chocolate varieties although these high quality product represent a tiny percentage of the chocolate produced.
Cleaning gets rid of unwanted twigs, stones etc. for the roasting process. Roasting time and temperature are important to end product. The higher the temperature, the more bitter the chocolate so the more need for sugar etc. this is particularly common in the US. In Europe, beans are roasted at a lower temperature for a longer time and therefore have a richer flavour so less sugar is needed.
The nib is then separated from shell with a mill in a process called kibbling. These are then ground to produce cocoa mass or liquor (an average cocoa bean contains 55 % cocoa butter). Sugar is then added and the mixture is kneaded into a dough.
The dough is then refined through five revolving steel rollers which reduces all the solid particles to 20 microns - or less for top quality chocolate. The 'mixture' which comes off at the top of the fifth roller is in powder or flake form which is barely perceptible to the touch. At this stage the chocolate contains approximately 55% cocoa butter.
The mixture is then conched which is essential at this stage for smoothness - called because the paddles used to look like shells and conch is Spanish for shell. The friction of the paddles, which are formed like a giant mixer, creates heat which melts all components so becomes liquid. More cocoa butter is added now - depending on the recipe. This homogenises the chocolate, develops the flavour and refines the particles.
The longer the 'conch' the better but ... not so long ago, it was a sign of a good chocolate when it was conched for four or five days. Today's technology has changed that to eight or ten hours.
The conching time should be long enough to drive off the unwanted volatile oils and bitterness but not too long to also get rid of some of the more complex chocolate flavours. Cocoa contains over 400 flavour compounds.
Liquid chocolate is 'loaded' on to thermostatically controlled tankers for national and international distribution OR is tempered to ensure proper crystallisation of cocoa butter and its even dispersal throughout the chocolate. Chocolate is then moulded into the familiar blocks that we buy!