Dark chocolate is a form of chocolate containing only cocoa solids, cocoa butter and sugar. Dark chocolate without added sweetener is known as bitter chocolate^[1] or unsweetened chocolate.^[2] As with the other two main types of chocolate (milk and white), dark chocolate is used for chocolate bars or as a coating in confectionery.

Government and industry standards of what products may be labeled "dark chocolate" vary by country and market.

History

Chocolate is made from the seeds of the tropical Theobroma cacao tree. Chocolate has been consumed over centuries.^[3] It may have been developed around 1500 BC^[4] in Central and South America as a drink by the Olmecs.^[5] Later, it was also made into a drink by the Mayan peoples for ceremonial purposes.^[5][6] They would add honey and cane sugar to make it sweeter, and other additional flavorings as a hot beverage.^[5][7]

Spanish explorers encountered chocolate in the early 1500s and introduced it to Spain.^[5] In the late 1600s, milk was also added to the dark chocolate beverage by Hans Sloane, who resided in Jamaica at the time.^[3] Chocolate was finally made into a solid form in the 18th century and was mass-produced in the 19th century, with several innovations, in particular by Coenraad Johannes van Houten^[5][8] and Rodolphe Lindt, who invented a machine to mix and aerate chocolate, giving it a smooth texture.^[9]

In the late 19th century, Daniel Peter and Henri Nestlé manufactured milk chocolate which became commonly favored.^[5] As a consequence, the term dark chocolate was coined to distinguish the traditional chocolate from the new form. In the late 20th century, demand for dark chocolate increased.^[3][5]

Nutrition

Nutrients in dark chocolate include 46% carbohydrates, 43% fats, 8% protein, and 1% water (table). In a 100-gram (3+1⁄2-ounce) reference serving, dark chocolate provides 2,500 kilojoules (600 kilocalories) of food energy and is a rich source (defined as more than 20% of the Daily Value, DV) of several dietary minerals, such as iron, copper, manganese, magnesium, phosphorus, and zinc. It also contains a moderate amount of vitamin B12 (table).

As of 2018,^[update] high-quality clinical research has not been conducted to evaluate the effects of compounds found in cocoa on physiological outcomes, such as blood pressure, for which only small (1–2 mmHg) changes resulted from short-term consumption of chocolate up to 105 grams and 670 milligrams of flavonols per day.^[10] Flavanols found in dark chocolate include the monomers catechin and epicatechin, and (to a lesser extent) the polymeric procyanidins, which remain under laboratory research.^[10]

Metal content

Chocolate, particularly dark chocolate, may contain appreciable levels of toxic heavy metals, such as cadmium, which may be present naturally in the soil of cocoa plantations.^[11] For products containing over 50% cocoa, the European Commission has set a limit for cadmium of 0.8 mg/kg, while for chocolate containing between 30%-50% cocoa, the limit is 0.3 mg/kg.^[11] The state of California recommends a maximum daily intake of 4.1 micrograms of cadmium.^[12]

According to a Consumer Reports study in 2022, several dark chocolate products were found to contain high levels of lead and cadmium when compared against California's maximum allowable daily dose levels.^[13]