# Dark chocolate

Dark chocolate is a form of chocolate made of cocoa solids, cocoa butter and sugar. Dark chocolate has a higher cocoa percentage than white chocolate, milk chocolate, and semisweet chocolate. Dark chocolate is valued for claimed—though unsupported—health benefits, and for being a sophisticated choice of chocolate. Similarly to milk and white chocolate, dark chocolate is used to make chocolate bars and as a coating for confectionery.
Dark chocolate gained much of its reputation from an effort by French chocolatiers in the late 20th century to assert a preference for dark chocolate in the French national palate, over milk chocolate. As this palate was exported to other countries, such as the United States, the associated values of terroir, bean-to-bar chocolate making and gourmet chocolates followed. Due to the high cocoa percentage, dark chocolate can contain particularly high amounts of heavy metals such as lead and cadmium. As of 2024, the dark chocolate market was projected to grow by over 9% per annum for the next four years, particularly driven by growth in the European market.
Dark chocolate has a more bitter and intense flavor than other types of chocolate, and compared to other types of chocolate, is reliant on the quality of the cocoa beans and cocoa butter used as ingredients. Making dark chocolate involves a process of mixing, refining, conching, and standardizing. Government and industry standards of what products may be labeled "dark chocolate" vary by country and market.

## Terminology

In Britain, dark chocolate is known as plain chocolate. In North America and continental Europe, dark chocolates are categorized into sweet, semi-sweet, and bittersweet chocolate, the last used as a general term in North America for dark chocolate. Dark chocolate without added sweetener is known as bitter chocolate, unsweetened chocolate, or 100% chocolate.

## History

After the domestication of the cacao tree over 5000 years ago, indigenous Americans began producing cacao beverages. The earliest people known to have used the cacao plant are the ancient Mayo-Chinchipe people of what’s now Ecuador in circa 3300 BC. While it is unclear when non-alcoholic cacao beverages were first consumed, some academics claim this occurred by 1650 BC. Other academics claim this occurred by circa 1800 BC by ancient Olmec people of what’s now Mexico and Central America. When the Spanish conquistadors first tasted chocolate around 1520, there were many different variations of cacao beverages, of which one, made in the Guatemala, was referred to as chocolate. After this area became a dominant producer of cacao in the later 16th century, chocolate became the word for all cacao drinks. Europeans adapted chocolate with Old World ingredients, including sugar, and after bringing it to Europe, it spread and became popular among the elite. Over the following centuries it became simpler and less spiced.
In 1828, Coenraad Johannes van Houten received a patent for the manufacturing process for making Dutch cocoa, removing cocoa butter from cocoa liquor, and creating the potential for mass production. In 1847, the first modern chocolate bar was created by the British chocolate maker Fry's, and over the next century it would be improved with a series of new techniques including conching and tempering. With the invention of the modern milk chocolate in 1875, the term dark chocolate was coined to distinguish the traditional chocolate from the new form. By 1899 in the United States, dark chocolate was considered masculine and inappropriate for children. For much of the following century in the US, dark chocolate was not consumed by itself, but together with other foods such as ice cream, nuts and coconut. During the World Wars, dark chocolate was fortified with vitamins A, B$_1$, B$_2$, C, D, niacin and sometimes calcium to prevent malnutrition. Beginning in the 1930s and 1960s respectively, British chocolate makers Rowntree's and Cadbury began associating their dark chocolate products with upper-class women in their advertising. This was a response to market research of the time claiming dark chocolate was favored by the higher social classes, compared to a working class who preferred milk chocolate.
During the late 1970s, when the price of cocoa was very low, the palate of French connoisseurs moved strongly in favor of dark chocolates and against milk chocolate after advocacy from chocolatier Robert Linxe. At the same time, some American consumers began to take interest in dark chocolates for the first time, often sourcing product from France and Belgium. The following decade, a nationwide campaign in France aimed to move the public to appreciate locally produced dark chocolates with sophisticated flavor. Taste makers and producers worked together to create flavor standards using concepts borrowed from wine connoisseurship. This was motivated by foreign firms capturing swathes of the French confectionary market at the expense of local chocolatiers. Simultaneously, high-quality dark chocolate began to be attributed psychoactive and possibly aphrodisiac qualities due to its theobromine content. In America, broader recognition of dark chocolate as distinct from milk chocolate, and of the concepts of bean origin and the percentage of cocoa arose in the years following 1984, when French chocolate manufacturer Valrhona entered the US market, selling initially to pastry and chocolate manufacturers, and later to the general public.
In the 1990s, French flavor standards, having gained mass uptake domestically, were intentionally exported to the United States. These standards, laid out in published guides and chocolate tastings, evoked terroir, bean varietals and estate growths. Chocolates with high cocoa content and novel flavors (such as pepper, ginger and fennel) were promoted. These chocolates were significantly more expensive than the chocolates that had previously consumed. By the late 2000s, a preference for dark chocolate was seen as the sign of a "discriminating palate" in the United States.

## Characteristics

Dark chocolate is harder than milk chocolate, due to its particle size and fat and lecithin content. Dark chocolate has a more bitter and intense flavor than milk chocolate, due to a higher proportion of cocoa mass, which contains theobromine, caffeine, l-leucine, and catechin flavonoids. Compared to other types of chocolate, the quality of cocoa beans is more important for flavor, and the most highly flavored cocoa butters are reserved for dark chocolates. Dark chocolate can exhibit burnt, chocolate, smoky, nutty and sour flavors, among others. These variations are particularly noticeable among dark chocolates using single-origin cocoa beans. While the appeal of the taste of sugary and milky milk chocolate is often immediately apparent, dark chocolate's more complex flavors can lead to it being more of an acquired taste.
Dark chocolate contains 60 compounds contributing to its flavor, with 33 of these considered particularly important. Basic and neutral compounds are responsible for a "chocolate" flavor, while acidic compounds contributed more sweet flavors. Some of these compounds are the product of Maillard reactions. Some manufacturers age dark chocolate to improve flavor. This is done at a minimum for a few weeks, and it is debated whether ageing for more time is desirable. The antioxidants in cocoa solids are responsible for preserving chocolate; dark chocolate has a shelf life of about two years, longer than milk chocolate. Dark chocolate can range in color from mahogany to black.

## Health effects
### 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, including copper, iron, magnesium, manganese, phosphorus, potassium, and zinc (table).

### Research

While dark chocolate is popularly considered a health food, only limited high-quality clinical research has 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, high consumption of chocolate up to 105 grams and 670 milligrams of flavonols per day. A recent 2024 study though showed that those who consumed more than five servings a week of dark chocolate had about 20% lower risk of developing type 2 diabetes.
Flavanols found in dark chocolate include the monomers catechin and epicatechin, and (to a lesser extent) the polymeric procyanidins, which remain under laboratory research. Flavanols break down as cocoa beans are fermented, roasted and treated with the Dutch process. To consume enough cocoa flavanols for the presumed effects claimed in some limited studies requires eating at least around 4.75 ounces (135 g) of dark chocolate a day, which also involves intake of significant amounts of sugar and saturated fats. The chocolate industry, and in particular Mars, Inc., has funded research to promote chocolate as a health food. As of 2018, Mars had funded more than 150 studies into cocoa flavanols since the 1980s. That year, they said they would no longer try to imply chocolate is a health food.
A 2021 systematic review of the health effects of chocolate and cocoa found high-quality research had still not been performed to evaluate physiological outcomes. The only health effects observed were improvements in lipid profiles; control subjects showed no significant differences in terms of skin, cardiovascular, anthropometric, cognitive and quality of life outcomes.

### 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, particularly in Latin America. 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. After these limits came into enforcement in 2019, similar regulations were enforced in other jurisdictions across the world. The state of California recommends a maximum daily intake of 4.1 micrograms of cadmium.
A 2024 report analyzing dark chocolate and cocoa samples in the United States from 2014 to 2022 found that multiple samples exceeded Prop 65 levels for heavy metals: 43% of samples exceeding levels for lead, and 35% exceeding levels for cadmium. However, a 2024 study published in Food Research International found that high metal content in dark chocolate may pose health concerns mainly only for children.

## Manufacturing
### Ingredients

Dark chocolate is mainly a combination of chocolate liquor, cocoa butter and sugar. Milk fats are often added to dark chocolate to delay the formation of chocolate bloom; dark chocolate containing 1–2% milk fat experiences a delay in blooming. Milk fats are also added by some manufacturers to slightly soften dark chocolate and allow for more flavor to be released. During the final step of standardizing, emulsifiers such as lecithin or PGPR are added to improve texture. Some manufacturers add vanilla or vanillin as a flavoring.
Many dark chocolate products sold label the cocoa percentage. This percentage refers to the percent of the chocolate that is chocolate liquor and cocoa butter, with almost all of the rest being sugar. As what part is chocolate liquor and what part is cocoa butter is not identified, chocolates with an identical cocoa percentage can have vastly different compositions and characteristics. Chocolates containing more chocolate liquor are more intensely flavored and more viscous. Variability in the quality of cocoa beans mean chocolates with lower cocoa percentages can have more desirable flavors than those with higher percentages.

### Process

The basic process of making dark chocolate involves mixing, refining, conching and standardizing. With its relatively low viscosity, dark chocolate is the easiest chocolate to handle in manufacturing. In the mixing stage, chocolate liquor is combined in a melanger with sugar and some cocoa butter, mixing until a paste is formed. As long as the cocoa mass has been correctly milled, the refining process for dark chocolate is primarily about grinding down sugar. Refining involves putting chocolate through a refiner machine, which carries the cocoa mass through large steel rollers set to varying widths, enveloping them in fat until the chocolate particles are as small as is desired, and the cocoa mass is a fine powder. Refining dark chocolate to be finer makes the cocoa flavor more intense, and the ideal particle size for dark chocolate has been identified as 35 μm. Dark chocolates with a higher cocoa mass require special accommodations here, as, with high portions of cocoa butter, there can be issues with the roller refining process. These accommodations can involve beginning the refining process with less cocoa mass, and only integrating the rest during the conching stage. Other alternatives include using cocoa powder or processing in a ball mill.
Conching machines mix and knead a cocoa mass, changing the flavor and texture. More than for other types of chocolate, conching dark chocolate serves to remove undesirable flavors. Dark chocolate is conched at higher temperatures than other chocolates, between 158–180 °F (70–82 °C). If dark chocolate takes on moisture during the conching process, for example by being conched in the same room as milk chocolate with neither enclosed, the dark chocolate can become undesirably thick and develop unpleasant flavors. During the final step of standardizing, emulsifiers and sometimes vanilla flavorings are added. If needed to reach a desired yield or viscosity, more cocoa butter can be added before the mixture undergoes laboratory testing for particle size and food safety. If these standards are met, it is pumped through fine screens to remove any agglomerates. Tempering is performed at different temperatures than for milk chocolate because of how milk fats impact the formation of crystal lattices.

### Legal requirements

According to a 2000 European Union directive, dark chocolate must contain at minimum 18% cocoa butter, not less than 35% total dry cocoa solids and a minimum of 14% dry non-fat cocoa solids. As of 2017, the United States Food and Drug Administration did not regulate a standard identity for dark chocolate, which had led to concerns that some products were made from vegetable fats and customers had been misled by health claims.

## Market

During the 2010s, demand for high-cocoa dark chocolate increased in light of research linking the antioxidant content with a reduced risk of cancer and cardiovascular health. As of 2019, demand for dark chocolate containing more than 70% cocoa, particularly using beans from a single-source, was increasing.
France is considered the "home of dark chocolate", and the industry there uses the term Grand Cru to refer to particularly valued chocolates. As of 2018, retailers and dark chocolate manufacturers there received an equal portion of over two thirds of the margins generated across the cocoa supply chain for dark chocolate tablets. As of 2016, the dark chocolate market was concentrated more in Continental Europe than the United States and England. 31% of chocolate produced was dark chocolate. From 2005 to 2011, dark chocolate consumption in the US increased by 9% per annum. Beyond beliefs around the healthiness of dark chocolate, increased demand for dark chocolate in the United States has also been attributed to a trend of consumers expanding preferences beyond traditional mass-produced chocolate. In the US, this growth has occurred at the expense of milk chocolate.
A large percentage of chocolates sold by the Swiss chocolate maker Lindt are dark chocolate of varying cocoa solid percentages, including 70%, 85% and 90%. In a 2024 market research report entitled Dark Chocolate Market Research, the authors identified various forms dark chocolate was sold in: bars, blocks, pieces, chunks, bonbons and as other confectionary items. Across these forms, it was consumed as a snack, and used by confectioners and in recipes. The report identified Europe as one of the largest producers and the market overall as having grown by over 8 percent since the previous year. About a third of sales were identified as from organic chocolate, and the market as influenced by the volatile cost of cocoa beans.

## Variants

Low-sugar dark chocolate is made by replacing sugar with maltitol, a sugar alcohol, which may be replaced with a fiber blend and stevia. According to Dark Chocolate Market Analysis, the markets for dark chocolates marketed as gluten-free and gourmet were growing. Those dark chocolates marketed as gourmet were identified as made using flavor cocoa, dried fruits, and using sugars such as coconut sugar. Other varieties of dark chocolate identified included artisanal, organic, milk and vegan chocolates. Nuts, cereals, creams, liqueurs and syrups can be added. Dark chocolates range in the percentage of cocoa solids they contain, from products being called dark chocolate with percentages from 40% to 100%.
Flavor cocoas, cocoas purchased for a premium that are valued for their flavor or other qualities are mostly used for dark chocolate. These include single source chocolates. Single source dark chocolates are often from countries such as Ecuador and Venezuela. Fruity, astringent and acidic flavors are highlighted in these chocolates, while flavors of smoke and mold flavors are avoided as they cannot be removed by further processing.