It’s funny to think that a bar of chocolate starts out using the fruit from a tree that might grow in your garden…if you live in the tropics!

Here you can discover where cocoa trees grow, what they produce and how you end up with the cocoa, dark and milk chocolate we all know and love.

From Trees to Beans

Cocoa beans come from cocoa pods that grow on cocoa trees – simple! The cocoa tree, (real name Theobroma Cacao), grows in warm, humid places near the Equator.  There’s got to be guaranteed rainfall and fertile soil for it to thrive, and Ghana, the Ivory Coast, Brazil, and Nigeria are all perfect – production’s increasing in Malaysia too. 

A cocoa tree looks a bit like an apple tree but has broader, rich green leaves. It flowers and fruits all year round, and produces large cocoa pods that sprout from tree trunks and main branches. There’s not that many of them though – each tree only has 20-30 pods a year. Take a look inside the pods and you’d see 30-40 seeds sitting in a sweet white pulp rather like cotton wool – these are the cocoa beans. And no wonder cocoa is precious; it takes a whole year’s crop from one tree to make 454 grammes (1lb) of cocoa.

Different trees, different cocoa

There are three main types of cocoa: Forastero, Criollo and Trinitario – this last one is a cross between the first two. Forastero is widely grown – it’s a hardy tree producing the strongest flavour beans. And within Forastero, a variety called Amelonado is most popular, largely grown in West Africa and Brazil. Criollo trees aren’t as tough as Forastero. Its beans have a milder chocolate flavour and a unique aroma. They’re grown in Central and South American and Indonesia.

Trinitario isn’t found in the wild, but is grown in the Caribbean as well as in Cameroon and Papua New Guinea. Cadbury get their cocoa from Ghana in West Africa, where the main harvesting period is October to December. When they’re ripe, the cocoa pods turn a rich golden colour. They’re cut down from the trees and split open, and the pulp and beans are removed from the outside husk.

To get a good chocolate flavour, the beans then have to be fermented. There are two main methods: Heap and Box. In West Africa the Heap method is used. The cocoa beans are piled up on a layer of banana tree leaves, with more leaves on top to cover them. Then they’re left for five or six days to ferment – this when much of the chocolate flavour develops. The pulp around the beans becomes liquid and drains away.

Next the wet beans are dried in the sun and turned frequently so they dry evenly – this is crucial because if any beans are still wet, they’ll go mouldy when they’re stored. Once the farmers are happy that the beans are dry, they’re taken to buying stations, where the beans are weighed and packed into sacks.

The Box method is used in the West Indies, Latin America and in Malaysia, and you tend to find it in large plantations. Over a tonne of beans is put in to a wooden box which has gaps in the base for air to get in and liquid to drain out. The boxes are covered in banana leaves and stored in a building for 6-8 days. They’re mixed a couple of times during this process, and then special equipment is used to dry them.

Processing the Beans

Once Cadbury have bought their cocoa beans, they arrive in the United Kingdom and are transported to one of the world’s most modern processing factories, at Chirk in North Wales. 

The sacks of beans are emptied out on to a conveyor belt and before anything else happens they’re cleaned to get rid of any dust and stones they’ve picked up along the way. Next the beans roasted in a big revolving drum called a continuous roaster. Hot air goes into it as the beans pass along it, and it’s during this process that you’ll really begin to smell chocolate!

The roasted beans are ‘kibbled’ (broken in to small pieces), then ‘winnowed’ – the brittle shells are blown away, leaving just the ‘nibs’, the centres of the beans. The nibs are ground between steel rollers until they become a chocolate-coloured liquid, rather like thick cream, over half of which is cocoa butter. The liquid is called ‘mass’ or ‘cocoa liquor’ and this is the basic ingredient for all cocoa and chocolate products.

Mass contains ‘cocoa butter’ and about half of is pressed out. You’re left with a solid block that can then be ground into cocoa powder.

How Dark Chocolate is Made

To make dark chocolate, cocoa mass is sent from Chirk to Cadbury’s chocolate making factories. It’s mixed with extra cocoa butter and sugar, then ground and ‘conched’. Conching is a crucial process: it means the chocolate is rolled and kneaded, transforming itself from a gritty substance to a very smooth one.  Chocolate also needs to be ‘tempered’. This involves cooling it to a particular temperature, to make it stable. It means you get a nice glossy finish, and you don’t get the problem of cocoa butter rising to the surface – which is harmless, but spoils the look of the chocolate.

Now the dark chocolate is ready to use and can be poured into moulds or over chocolate centres. The finished chocolate bars or individual chocolates sail on down the production line to be wrapped and packed into boxes ready for distribution.

How Milk Chocolate is Made

The cocoa mass is sent to the Cadbury milk factory near Hereford. Here it is mixed with sugar and fresh full cream milk, which has already been condensed into a thick liquid. The mixture is dried in vacuum ovens to become milk chocolate ‘crumb’. The milk chocolate crumb is taken to Cadbury chocolate factories and finely ground between enormous rollers before extra cocoa butter and special flavourings are added. 

The amount of cocoa butter added depends on what the chocolate is for – bar chocolate needs to be thick, but if it’s to cover assortments and bars with different centres, thinner chocolate is used. In the UK up to 5% vegetable fat is added too – this stabilises the chocolate and gives the ideal texture to ensure that the melting properties of the chocolate are precise and preserve the taste and ideal texture of the chocolate.

 Next, milk chocolate needs to be conched (rolled and kneaded so that it becomes silky smooth), and tempered (cooled to a particular temperature to make it more stable) – just like for dark chocolate. Now the chocolate’s ready for its final destination – maybe it’ll be poured over a Crunchie, become a Classic Dark, or end up as a lovely bar of Dairy Milk.

Moulded chocolate, countlines and enrobing

So once we’ve made dark chocolate and milk chocolate, what happens to it? That depends on what we’re making.  Bars of chocolate, like Cadbury Dairy Milk, are called ‘moulded’ products – because chocolate is poured into a mould to make them. Liquid chocolate is poured in, it’s shaken (to make sure it fits the mould perfectly), and then cooled, before being wrapped at high speed.

 ‘Countline’ products are things like Crunchie, with a chocolate covering around a different centre. The centres of the bars are laid out on a conveyer belt, and they pass under an ‘enrobing’ machine, which covers each bar in a layer of liquid chocolate. Chocolate assortments like Milk Tray are made the same way.