From Bean to Bar
The process of transforming the cacao bean into mouth-watering chocolate is a blend of art and science.
Cacao is grown on a tree that begins bearing fruit in the fifth year after planting. The plants are protected from the equatorial sun by the shade of taller trees, such as banana trees, that grow above them. Their average life is 25-40 years. Tiny, waxy, pink-and-white five petal blossoms that sprout in clusters on the tree trunk and older branches are where a cacao pod begins its life.
Cocoa Pod Types
In twelve months, a single tree can bear 50,000-100,000 cacao blossoms. Their life is short, not exceeding 48 hours, and on average, only 10 to 30 percent of a tree’s fruit will grow and develop into mature cacao pods. These pods are of several types:
- Criollo – The most valuable, it is long-ribbed, thin-skinned, and initially green but becomes red at maturity. The beans of this pod have a mild, nutty character and are known for their unique flavor.
- Forastero – The most widely cultivated species, it has a rounded pod, which is almost smooth and turns from green to yellow at maturity. The beans are strongly flavored and higher in fat and the tree is known for its heartiness.
- Trinitario – The hybrid of Criollo and Forastero, these beans have an aromatic flavor and the tree is suitable for cultivation.
The pods are usually shaped like a rugby ball and are an average of 20 cm in length. Each pod typically contains between 20 and 50 cream-colored seeds. The seeds, called beans, are strung in five chains or rows within the pod and are surrounded by a sweet white pulp. In some regions this pulp is used for preparing a refreshing drink as well as a type of jam; it is also a favorite of many animals, including monkeys, parrots and squirrels.
The cacao bean consists of a leathery seed coat, rich in tannin, which envelopes each seed, and consists of two halves. It contains cocoa butter, proteins, starch, alkaloids, essential oils and various substances, which will release their aroma at the roasting stage of chocolate making. The pleasant chocolate aroma is not at all apparent in the fresh seed. The beans from an average pod weigh less than two ounces. Approximately 400 beans are required to make one pound of chocolate. The cacao tree is so fragile and its roots are so shallow that it is unsafe for workers to climb the trunk to reach pods on the higher boughs. Because of this, they use long-handled steel knives (machetes) to reach the pods and harvest. They use extreme caution not to damage the floral clusters containing dormant buds because they are the promise of future harvests.
It requires training and experience to tell by appearance what cacao pods are ripe and ready for cutting. Ripe pods appear at all times because the growing season in the tropics is continuous, but the main and mid-season harvests—each lasting several months—are when most pods are collected. After being extracted from the tree, the harvested pods are gathered in a pile at the edge of the growing area and the pod-breaking operation begins. One or two expert blows with a machete will usually open the woody pods. The husk is then discarded.
Harvested cacao seeds are placed in piles and covered with banana leaves. This starts the fermentation process, lasting three to nine days, and generating temperatures of up to 125° F. The cacao beans themselves do not ferment; it is the pulp sugars outside the bean that are converted into acids, primarily lactic and acetic. At the same time, within the bean, the germ is killed, and hydrolyzing and oxidizing reactions occur, which give the cacao bean its characteristic flavor after roasting.
After fermenting, the beans are spread on racks to dry in the sun. For protection from the rain, the racks can be slid under roofs, or roofs moved out over the beans. On some farms, beans are dried mechanically in driers of various sizes and types, depending on the size of the operation. Hot air is forced through the beans, which are stirred regularly during the drying period. The process reduces the moisture content of the fermented beans from 60 percent to 5-7 percent.
Once grown, picked, fermented, dried and packed in 130-200 lbs. jute, sisal or burlap bags, the cacao beans are shipped to various ports for distribution to processing facilities. Quality control begins at the pier, where samples are taken randomly from each lot for analysis. The principal test in the judging of cocoa beans is the cut test to determine color and possible defects. After careful evaluation of the cocoa bean halves, conclusions are made as to the degree of fermentation and flavor development of the raw cocoa. Additional analysis includes testing the beans for size (100 gram bean count), moisture, and foreign matter. If all of the test results are within the specifications, delivery is accepted and the beans are shipped to a processing facility. Upon arrival, samples are again taken and retested for comparison with the pre-shipment test results. Since Wilbur purchases many flavor-grades of beans, a small test batch of chocolate liquor is made and tasted before final approval is granted for the lot of beans to be used in manufacturing.
Only after the final approval is given does the manufacturing process begin. The beans are dumped onto a grate and undergo a series of screening steps to remove foreign matter such as stones, twigs, pod fragments, sack threads, dust, etc. They are scanned by an electro-magnet to remove any metallic particles. The beans are then micronized in a gas fired oven. This loosens the shells to increase efficiency of shell removal and also helps lower the microbiological loading of the raw beans.
The cacao bean then goes into a winnowing machine, where it is cracked into small pieces and the fragments of shell are removed. The husked and winnowed beans are now called “nibs.” It is at this point in the process that the nibs of many varieties are roasted and blended. Roasting of the nibs is a key processing step to the development of chocolate flavor and is the final microbiological kill step. It is a test of the chocolate maker’s skill to combine the nibs to achieve the subtle mixtures that ensure the quality and flavor consistency that are the hallmarks of each Wilbur product.
Roasted nibs then undergo a grinding process and pass through mills, which transform them into a fine paste. The heat generated by the friction of the milling process melts the cocoa butter in the paste, constituting 50-60 percent of the bean, and produces a thick, liquid mixture called chocolate liquor. This liquid contains no alcohol and is extremely bitter. At this point, additional ingredients—such as sugar, vanilla and milk—are added according to each chocolate’s recipe to form a chocolate mass. The chocolate is already quite tasty, but has a somewhat gritty feel in the mouth. To break down the particles, the mass is conveyed to a refiner where it passes through vertically-stacked, rotating steel rollers under heavy pressure and emerges as a fine, flaky film.
Even at this point, however, the resulting product is still not smooth enough, the flavors of the various ingredients have still not emerged, and the pure, rounded chocolate aroma is still not fully developed, so the mass is conveyed for further processing. This stage is called conching and is a processing step involving high shear and high temperature mixing for extended periods of time. The main purpose of conching is flavor development, but is also for moisture reduction and emulsification. The churning action not only mixes the chocolate but also ventilates it to ensure perfect flavor components. Additional flavors can also be added at this time.
After conching, the chocolate is stored in large tanks and shipped to customers as liquid chocolate or pumped to individual tempering units. These are connected to moulding and depositing machines where 10 lb. blocks, chips, chunks, rods and flakes are produced.
At every step of this complex manufacturing process, there is continuous sampling of the product. In-process quality assurance laboratories are located in the midst of every facility for on-the-spot testing.
Some Cargill products are only approved for use in certain geographies, end uses, and/or at certain usage levels. It is the customer's responsibility to determine, for a particular geography, that (i) the Cargill product, its use and usage levels, (ii) the customer's product and its use, and (iii) any claims made about the customer's product, all comply with applicable laws and regulations.