Gifts of chocolate molded into different shapes (such as eggs, hearts, and coins) are traditional on certain Western holidays, including Christmas, Easter, Valentine's Day, and Hanukkah.

[11] Evidence for the domestication of the cacao tree exists as early as 5300 BP in South America, in present-day southeast Ecuador by the Mayo-Chinchipe culture, before it was introduced to Mesoamerica.

[12] It is unknown when chocolate was first consumed as opposed to other cacao-based drinks, and there is evidence the Olmecs, the earliest known major Mesoamerican civilization, fermented the sweet pulp surrounding the cacao beans into an alcoholic beverage.

[18][19][20][21][22][23] Chocolate in Mesoamerica was a bitter drink, flavored with additives such as vanilla, earflower and chili, and was capped with a dark brown foam created by pouring the liquid from a height between containers.

While Spanish conquistador Hernán Cortés may have been the first European to encounter chocolate when he observed it in the court of Moctezuma II in 1520,[27][28] it proved to be an acquired taste,[29][30] and it took until 1585 for the first official recording of a shipment of cocoa beans to Europe.

In the 19th century, engine-powered milling was developed,[38][39] and in 1828, Coenraad Johannes van Houten received a patent for a process making Dutch cocoa.

[42] In the early 20th century, British chocolate producers including Cadbury and Fry's faced controversy over the labor conditions in the Portuguese cacao industry in Africa.

"[43] While conditions somewhat improved with a boycott by chocolate makers,[39][44] slave labor among African cacao growers again gained public attention in the early 21st century.

Recent genetic studies suggest the most common genotype of the plant originated in the Amazon basin and was gradually transported by humans throughout South and Central America.

In some cocoa-producing regions an association between filamentous fungi and bacteria (called "cocobiota") acts to produce metabolites beneficial to human health when consumed.

The conching process produces cocoa and sugar particles smaller than the tongue can detect (typically around 20 μm) and reduces rough edges, hence the smooth feel in the mouth.

If refrigerated or frozen without containment, chocolate can absorb enough moisture to cause a whitish discoloration, the result of fat or sugar crystals rising to the surface.

One hundred grams of milk chocolate is an excellent source (over 19% of the Daily Value, DV) of riboflavin, vitamin B12 and the dietary minerals, manganese, phosphorus and zinc.

[100] Chocolate may be a factor for heartburn in some people because one of its constituents, theobromine, may affect the esophageal sphincter muscle in a way that permits stomach acids to enter the esophagus.

[105] In sufficient amounts, the theobromine found in chocolate is toxic to animals such as cats, dogs, horses, parrots, and small rodents because they are unable to metabolize the chemical effectively.

[106] If animals are fed chocolate, the theobromine may remain in the circulation for up to 20 hours, possibly causing epileptic seizures, heart attacks, internal bleeding, and eventually death.

Medical treatment performed by a veterinarian involves inducing vomiting within two hours of ingestion and administration of benzodiazepines or barbiturates for seizures, antiarrhythmics for heart arrhythmias, and fluid diuresis.

According to the Merck Veterinary Manual, approximately 1.3 grams of baker's chocolate per kilogram of a dog's body weight (0.02 oz/lb) is sufficient to cause symptoms of toxicity.

[110][111] Various studies point not to chocolate, but to the high glycemic nature of certain foods, like sugar, corn syrup, and other simple carbohydrates, as potential causes of acne,[110][111][112][113] along with other possible dietary factors.

[117][118] If mood improvement from eating chocolate occurs, there is not enough research to indicate whether it results from the favorable flavor or from the stimulant effects of its constituents, such as caffeine, theobromine, or their parent molecule, methylxanthine.

[119] Reviews support a short-term effect of lowering blood pressure by consuming cocoa products, but there is no evidence of long-term cardiovascular health benefit.

[123] While daily consumption of cocoa flavanols (minimum dose of 200 mg) appears to benefit platelet and vascular function,[124] there is no good evidence to indicate an effect on heart attacks or strokes.

In 2007, the Chocolate Manufacturers Association in the United States, whose members include Hershey, Nestlé, and Archer Daniels Midland, lobbied the Food and Drug Administration (FDA) to change the legal definition of chocolate to let them substitute partially hydrogenated vegetable oils for cocoa butter, in addition to using artificial sweeteners and milk substitutes.

In June 2007, in response to consumer concern about the proposal, the FDA reiterated "Cacao fat, as one of the signature characteristics of the product, will remain a principal component of standardized chocolate.

[142] As of 2007, roughly two-thirds of the world's cocoa was produced in West Africa, with 43% sourced from Ivory Coast,[143] which commonly used child labor.

In February 2010, Kraft also acquired British-based Cadbury;[151] Fry's, Trebor Basset and the fair trade brand Green & Black's also belongs to the group.

[156] As of 2017, approximately 2.1 million children in Ghana and Ivory Coast were involved in farming cocoa, carrying heavy loads, clearing forests, and being exposed to pesticides.

"[153] Reported in 2018, a 3-year pilot program – conducted by Nestlé with 26,000 farmers mostly located in Ivory Coast – observed a 51% decrease in the number of children doing hazardous jobs in cocoa farming.

[158][161] In the 2000s, some chocolate producers began to engage in fair trade initiatives, to address concerns about the marginalization of cocoa laborers in developing countries.

The novel centers on a poor boy named Charlie Bucket who takes a tour through the greatest chocolate factory in the world, owned by the eccentric Willy Wonka.