CHAPTER 1
The History of Chocolate
Chocolate is almost unique as a food in that it is solid at normal room temperatures yet melts easily within the mouth. This is because the fat in it, which is called cocoa butter, is mainly solid at temperatures below 25 °C when it holds all the solid sugar and cocoa particles together. The fat is, however, almost entirely liquid at body temperature, enabling the particles to flow past one another, so the chocolate becomes a smooth liquid when it is heated in the mouth. Chocolate also has a sweet taste that is attractive to most people.
Strangely chocolate began as a rather astringent, fatty and unpleasant tasting drink and the fact that it was developed at all is one of the mysteries of history.
CHOCOLATE AS A DRINK
The first known cocoa plantations were established by the Maya in the lowlands of south Yucatan about 600 ad. Cocoa trees were being grown by the Aztecs of Mexico and the Incas of Peru when the Europeans discovered central America . The beans were highly prized and used as money as well as to produce a drink known as chocolatl. The beans were roasted in earthenware pots and crushed between stones, sometimes using decorated heated tables and mill stones, similar to the one illustrated in Figure 1.1. They could then be kneaded into cakes, which could be mixed with cold water to make a drink. Vanilla, spices or honey were often added and the drink whipped to make it frothy. The Aztec Emperor Montezeuma was said to have drunk 50 jars of this beverage per day.
Christopher Columbus bought back some cocoa beans to Europe as a curiosity, but it was only after the Spaniards conquered Mexico that Don Cortez introduced the drink to Spain in the 1520s. Here sugar was added to overcome some of the bitter, astringent flavours, but the drink remained virtually unknown in the rest of Europe for almost a hundred years, coming to Italy in 1606 and France in 1657. It was very expensive and, being a drink for the aristocracy, its spread was often connected to connections between powerful families. For example the Spanish princess, Anna of Austria, introduced it to her husband King Louis XIII of France and the French court in about 1615. Here Cardinal Richelieu enjoyed it both as a drink and to aid his digestion. Its flavour was not liked by everyone and one Pope in fact declared that it could be drunk during a fast, because its taste was so bad.
The first chocolate drinking houses were established in London in 1657 and it was mentioned in Pepys's Diary of 1664 where he wrote that 'jocolatte' was 'very good'. In 1727 milk was being added to the drink. This invention is generally attributed to Nicholas Sanders. During the 18th century White's Chocolate House became the fashionable place for young Londoners, while politicians of the day went to the Cocoa Tree Chocolate House. These were much less rowdy than the taverns of the period. It remained however, very much a drink for the wealthy.
One problem with the chocolate drink was that it was very fatty. Over half of the cocoa bean is made up of cocoa butter. This will melt in hot water making the cocoa particles hard to disperse as well as looking unpleasant because of fat coming to the surface. The Dutch, however, found a way of improving the drink by removing part of this fat. In 1828 Van Houten developed the cocoa press. This was quite remarkable, as his entire factory was manually operated at the time. The cocoa bean cotyledons (known as cocoa nibs) were pressed to produce a hard 'cake' with about half the fat removed. This was milled into a powder, which could be used to produce a much less fatty drink. In order to make this powder disperse better in the hot water or milk, the Dutch treated the cocoa beans during the roasting process with an alkali liquid. This has subsequently become known as the Dutching process. By changing the type of alkalising agent, it also became possible to adjust the colour of the cocoa powder.
EATING CHOCOLATE
Having used the presses to remove some of the cocoa butter, the cocoa powder producers were left trying to find a market for this fat. This was solved by confectioners finding that eating chocolate could be produced by adding it to a milled mixture of sugar and cocoa nibs. (The ingredients used to make dark chocolate are shown in Figure 1.2.) If only the sugar and cocoa nibs were milled and mixed together they would produce a hard crumbly material. Adding the extra fat enabled all the solid particles to be coated with fat and thus form the hard uniform bar that we know today, which will melt smoothly in the mouth.
Almost twenty years after the invention of the press, in 1847, the first British factory to produce a plain eating chocolate was established in Bristol in the UK by Joseph Fry.
Unlike Van Houten, Fry used the recently developed steam engines to power his factory. It is interesting to note that many of the early chocolate companies, including Cadbury, Rowntree and Hershey (in the USA) were founded by Quakers or people of similar religious beliefs. This may have been because their pacifist and teetotal beliefs prevented them working in many industries. The chocolate industry was, however, regarded as being beneficial to people. Both Cadbury and Rowntree moved to the outside of their cities at the end of the 1890s, where they built 'garden' villages for some of their workers. Fry remained in the middle of Bristol and did not expand as quickly as the other two companies. It eventually became part of Cadbury.
With the development of eating chocolate the demand for cocoa greatly increased. Initially much of the cocoa came from the Americas. The first cocoa plantation in Bahia in Brazil was established in 1746. Even before this, the Spaniards had taken cocoa trees to Fernando Po (Biyogo), of the coast of Africa, and this soon became an important growing area. In 1879 a West African blacksmith took some plants home to the Gold Coast (now Ghana). The British Governor realised its potential and encouraged the planting of trees, with the result that Ghana has become a major source of quality cocoa. Other European powers also encouraged the growing of cocoa in their tropical colonies, e.g. France in the Ivory Coast (Côte D'voire), which is now the world's largest producer of cocoa.
The chocolate made by Fry was initially a plain block and it was only in 1876 that the first milk chocolate was made by Daniel Peter in Switzerland. Chocolate can not contain much moisture, because water reacts with the sugar and turns melted chocolate into a paste rather than a smoothly flowing liquid (see Project 5 in Chapter 10). As little as 2% of moisture can give a product a poor shelf-life as well as an inferior texture. This meant that Daniel Peter had to find some way of drying the plentiful supply of liquid milk that he found in his own country. He was helped in this by the recent development of a condensed milk formula by Henri Nestlé. This meant that he had much less water to evaporate. Also he was able to remove the remaining moisture using relatively cheap water-powered machines. In most countries milk chocolate products are now much more popular than plain chocolate ones.
In order for the chocolate to feel smooth on the tongue, when it melts in the mouth, the solid non-fat particles must be smaller than 30 microns (µm; 1000 microns = 1 mm). The chocolates made by Fry and Peter were ground using granite rollers, which could not mill as fine as this, so they still had a gritty texture. Groups of particles also joined together to form agglomerates, and some of the fat did not coat the particles very well owing to poor mixing. All these effects gave the chocolate a poor texture. In addition the chocolate tended to taste bitter because of the presence of some acidic chemicals (see Chapter 4).
In 1880 Rodolphe Lindt, in his factory in Berne in Switzerland, invented a machine which produced a smoother, better tasting chocolate. This was known as a conche, because its shape was similar to that of the shell with that name (Figure 1.3). It consisted of a granite trough, with a roller, normally constructed of the same material, which pushed the warm liquid chocolate backwards and forwards for several days. This broke up the agglomerates and some of the larger particles and coated them all with fat. At the same time moisture and some acidic chemicals were evaporated into the air, producing a smoother, less astringent tasting chocolate. A schematic diagram of the chocolate making processes is shown in Figure 1.4.
Chocolate Crumb
In the early part of the 20th century the milk used to make chocolate had poor keeping qualities. This caused problems for the chocolate industry, whose major sales were at Christmas, a time of the year when there was a very limited supply of fresh milk. In the UK and some other countries this led to the development of an intermediate ingredient called chocolate crumb.
The cocoa nibs contain substances known as antioxidants. These restrict the breaking up of the fats, which would normally make the milk fat turn sour. In addition sugar was known to extend the shelf-life of foods (it is used in jams etc.). The chocolate manufacturers therefore added sugar and cocoa to the milk and dried them together. This produced chocolate crumb, which had a shelf-life of at least a year. Milk produced during the spring peak could then be used to make chocolate the following Christmas. The drying process, however, introduced some cooked flavours into the chocolate and it is for this reason that many UK chocolates taste different from some continental European ones, which are made from milk powder.
White Chocolate
The first white chocolate was made in 1930. It was made from sugar, milk powder and cocoa butter. The preserving qualities of the cocoa antioxidants are mainly in the dark cocoa material. This means that white chocolate does not keep as well as milk chocolate, and also that it should be kept in a non-transparent wrapper, as light will speed up the decomposition of milk fat.
CHOCOLATE MARKETING IN THE UK
As technology improved, chocolate was used to coat other ingredients, or to be part of a product rather than just a bar. In the 1930s many of these were developed and have remained popular to this day. Good examples of this are KitKat, Mars Bar and Smarties. At this time products also became known under brand names rather than that of the manufacturer. Some companies, like Cadbury, tended to give both equal prominence.
During the war few cocoa beans were shipped from the plantations and strict rationing was introduced. Many leading brands were not produced at all. Rationing in the UK ended in April 1949, but the rush to buy was so great that, by June, 60% of confectionery shops had nothing left to sell. Rationing was reimposed until February 1953.
Consumption rose very quickly, but over the last ten years has been more constant with an average of about 8 kg/person per annum of chocolate confectionery being eaten in many Western European Countries (this does not include chocolate biscuits). Switzerland has the highest consumption at about 9.5 kg/person per annum. This makes the confectionery industry a very important one. The combined sales of sugar and chocolate confectionery in the UK are more than those of tea, newspapers and bread put together.
CHOCOLATE IS GOOD FOR YOU
Antioxidants in food are known to protect the body against chemicals called free radicals that damage cells. Cocoa is a known source of antioxidants and in 1999 doctors from the National Institute of Public Health and the Environment in Bilthoven in the Netherlands examined chocolate for its catechins content. These are from the family of flavonoids, which are among the most powerful antioxidants. They found that dark chocolate contained 53.5 mg per 100 g, which is four times that in tea. Drinking a cup of tea a day is said to reduce the chance of a heart attack.
Certain fats are said to cause an increase in cholesterol. Because of its triglyceride structure (see Chapter 6) cocoa butter has been found to be neutral in this respect. Studies by Prof. Kris-Etherton in the USA, where high risk individuals were fed large amounts of chocolate, showed that their cholesterol level remained unaffected.
CHAPTER 2
Chocolate Ingredients
COCOA BEANS
Cocoa Trees
To be called chocolate, a product must contain cocoa. The cocoa or cacao tree (Theobroma cacao, L.) originated in South and Central America, but is now grown commercially in suitable environments between 20° north and 20° south. These areas have a high average temperature (≥ 27°C) throughout the year and a constant high humidity, arising from a plentiful rainfall (1500-25 000 mm). The soil should be deep and rich and well drained and normally be less than 700 m above sea level, as strong winds will damage the crop.
The trees are relatively small, 12-15 m in height, and grow naturally in the lower level of the evergreen rainforest. In commercial plantations they are often sheltered by inter-cropping trees such as coconut and banana. The leaves are evergreen and are up to about 300 mm in length. Trees start bearing pods after 2 to 3 years, but it is 6 or 7 years before they give a full yield.
There are three types of cocoa. Criollo has beans with white cotyledons and a mild flavour. The trees are, however, relatively low yielding. Most cocoa is Forastero, which is more vigorous and often grown in West Africa in smallholdings (a family's cultivated land that is smaller than a farm). The third form, Trinitario, is usually thought to be a hybrid of the other two types.
The trees are attacked by many pests and diseases Some of the most serious are:
• capsids (insects that feed on sap, causing damage to plant tissue)
• black pod disease (fungi which attack mainly the pod, making them rot)
• witches' broom disease (fungal attack causing growths or brooms to develop from leaf buds, but also affects flowers and pods)
• cocoa pod borer moth (larva bores into the pods and affects the development of the beans)
Commercial Cocoa-Producing Countries
There are three major cocoa growing regions: West Africa, South-East Asia and South America. These are shown in Figure 2.1. The cocoa supplies from individual countries has changed dramatically over the last twenty years due to economic changes as well as pests and diseases.
Bahia in Brazil was a major cocoa growing area producing over 400000 tonnes in the mid 1980s. It now produces less than half of this, largely due to destruction by witches' broom disease. Instead of being a major exporter of beans, almost all are now processed and used within Brazil.
Over 40% of the world's crop is now grown in the Ivory Coast (Côte d'Ivoire). Production has increased dramatically over the last 30 years and a large proportion of European chocolate it made from this source of beans.
Ghana is the second highest producer with around 14% of the world's crop. It also has a good reputation for producing quality beans. Nigeria produces some cocoa, but the establishment of the oil and other industries resulted in alternative employment and a reduction in cocoa production.
Malaysia built up a fairly big cocoa production in the 1980s, but this has declined rapidly, partly due to pod borer infestation and also due to the greater profitability of other crops such as oil palm.
Indonesia is currently expanding its cocoa growing and is now producing almost as much as Ghana.
The flavour of the cocoa depends not only on the cocoa type, e.g. whether it is Criollo or Forastero, but also upon the climate and soil conditions etc. For some specialist chocolates, normally dark ones, beans are obtained from specific areas. These flavour cocoas, often Criollo, are produced in many smaller growing areas such as Ecuador, the Caribbean Islands and Papua New Guinea.
In addition to the flavour of the beans, the fat contained within it also changes according to the area of production. In general the nearer the equator that the tree is grown the softer is the fat, i.e. the easier it is to melt. This means that Malaysian cocoa butter is relatively hard, whereas most Brazilian cocoa butter is much softer. The harder is better for chocolates, which will be sold in summer, whereas the softer is preferable for frozen products, such as choc-ices, where the fat is hardened by the cold conditions. See Chapter 6 and Project 10 in Chapter 10.
Cocoa Pods
Tiny flowers (Figure 2.2), up to 100 000 in number, grow on the branches and trunk of the tree throughout the year. These grow into small green pods called cherelles (Figure 2.3), but take 5-6 months to develop into mature pods (Figure 2.4) between 100 and 350 mm long. Their weight ranges from 200 g to more than 1 kg and they exist in a wide variety of shapes and colours depending upon variety. Each pod contains some 30-45 beans.
The pods are carefully cut off the tree with a machete (cutlass), where they are within reach. For the higher branches it is necessary to use a special knife attached to a long pole, as is shown in Figure 2.5. Pods are normally harvested every 2-4 weeks over a period of several months, as they do not all ripen at the same time.
The pods are opened with a machete or cracked with a wooden club. The beans are oval in shape and covered in a white pulp (mucilage). The beans are separated from the majority of this pulp by hand.
The beans consist of an outer shell or testa surrounding two cotyledons (called nibs) and a small germ (the embryo plant). The cotyledons store the food for the developing seedling and also its first two leaves. Much of the food is in the form of a fat (cocoa butter) which accounts for over half of the dry weight of the bean. The moisture content of the bean at this stage is about 65%.
Fermentation
Fermentation Procedure
Correct fermentation is essential to produce a good flavour in the final chocolate. It is a process in which the bean is killed, so that it can not be spoiled by germination. In addition certain chemicals are formed, which upon heating give the taste of cocoa, whereas they themselves taste completely different, or may not even taste of anything at all. These are known as flavour precursors as they lead to the flavour, but aren't that flavour themselves. Unfermented beans may be pressed to produce cocoa butter, but the remaining solid cocoa material is not normally used to make chocolate.
