Manufacturers roast the fermented beans to transform flavor precursors into flavors.

Manufacturers grind the beans, add sugar, and then physically work the mixture to refine its flavor and create a silken texture.

The Cacao Bean The cacao tree, named The cacao tree, named Theobroma cacao Theobroma cacao by Linnaeus - by Linnaeus - theobroma theobroma is Greek for "food of the G.o.ds" - is a broad-leaved evergreen that grows between 20 north and south of the equator, and reaches about 20 feet/7 m in height. It produces fruits in the form of fibrous pods from 6 to 10 inches/1525 cm long, 3 or 4 inches/7.510 cm in diameter, and containing 20 to 40 seeds, or "beans," each about an inch/2.5 cm long, embedded in a sweet-tart pulp. is Greek for "food of the G.o.ds" - is a broad-leaved evergreen that grows between 20 north and south of the equator, and reaches about 20 feet/7 m in height. It produces fruits in the form of fibrous pods from 6 to 10 inches/1525 cm long, 3 or 4 inches/7.510 cm in diameter, and containing 20 to 40 seeds, or "beans," each about an inch/2.5 cm long, embedded in a sweet-tart pulp.

Varieties There are a number of different cacao varieties that fall into three botanical groups: the Criollos, Forasteros, and Trinitarios. Criollo trees produce relatively mild beans with some of the finest, most delicate flavors, reminiscent of flowers and tea. Unfortunately, they are also disease-p.r.o.ne, low-yielding trees, and so provide less than 5% of the world crop. High-yielding, robust Forasteros provide most of the world's cacao crop in the form of full-flavored "bulk" beans. Trinitarios are hybrids of a Criollo and Forastero, and have intermediate qualities. There are a number of different cacao varieties that fall into three botanical groups: the Criollos, Forasteros, and Trinitarios. Criollo trees produce relatively mild beans with some of the finest, most delicate flavors, reminiscent of flowers and tea. Unfortunately, they are also disease-p.r.o.ne, low-yielding trees, and so provide less than 5% of the world crop. High-yielding, robust Forasteros provide most of the world's cacao crop in the form of full-flavored "bulk" beans. Trinitarios are hybrids of a Criollo and Forastero, and have intermediate qualities.

West Africa (Ivory Coast and Ghana) now accounts for more than half of world cacao production, and Indonesia also out-produces Brazil, the largest producer in cacao's original homeland.

Storage and Defensive Cells Cacao beans consist mainly of the embryo's storage leaves, or cotyledons (p. 453), and contain two distinct groups of cells. Around 80% of the cells are storage depots of protein and of fat, or cocoa b.u.t.ter, nutrients that will feed the seedling as it germinates and develops on the shady floor of the tropical forest. The other 20% are defensive cells meant to deter the many forest animals and microbes from feasting on the seed and its nutrients. These cells are visible in the cotyledons as purplish dots, and contain astringent phenolic compounds, their chemical relatives the anthocyanin pigments, and two bitter alkaloids, theobromine and caffeine. The beans are moist, around 65% water. The composition of the dried fermented beans is shown in the box on p. 698. Cacao beans consist mainly of the embryo's storage leaves, or cotyledons (p. 453), and contain two distinct groups of cells. Around 80% of the cells are storage depots of protein and of fat, or cocoa b.u.t.ter, nutrients that will feed the seedling as it germinates and develops on the shady floor of the tropical forest. The other 20% are defensive cells meant to deter the many forest animals and microbes from feasting on the seed and its nutrients. These cells are visible in the cotyledons as purplish dots, and contain astringent phenolic compounds, their chemical relatives the anthocyanin pigments, and two bitter alkaloids, theobromine and caffeine. The beans are moist, around 65% water. The composition of the dried fermented beans is shown in the box on p. 698.

Fermentation and Drying The first important step in the development of chocolate flavor is the least controlled and predictable. Fermentation takes place where cacao is grown, on thousands of small farms and larger plantations, and may be done carefully or casually or not at all, depending on the resources and skill of the farmer. The quality of cacao beans thus varies tremendously, from unfermented to badly overfermented and even moldy. The first challenge for the chocolate manufacturer is to find good-quality, fully fermented beans. The first important step in the development of chocolate flavor is the least controlled and predictable. Fermentation takes place where cacao is grown, on thousands of small farms and larger plantations, and may be done carefully or casually or not at all, depending on the resources and skill of the farmer. The quality of cacao beans thus varies tremendously, from unfermented to badly overfermented and even moldy. The first challenge for the chocolate manufacturer is to find good-quality, fully fermented beans.

Soon after the cacao pods are harvested, workers break them open and pile the beans and sugary pulp together at the ambient tropical temperature. Microbes immediately begin growing on the sugars and other nutrients in the pulp. A proper fermentation lasts from two to eight days, and generally has three phases. In the first, yeasts predominate, converting sugars to alcohol and metabolizing some of the pulp acids. As the yeasts use up the oxygen trapped in the pile, they are succeeded by lactic acid bacteria, many of which are the same species found in fermented dairy products and vegetables. When workers turn the ma.s.s of beans and pulp to aerate it, the lactic bacteria are succeeded by acetic acid bacteria, the makers of vinegar, which consume the yeasts' alcohol and convert it into acetic acid.

Cacao pods contain many large seeds that are covered with a sweet pulp. The seeds consist mainly of the embryo's tightly folded food-storage cotyledons, which are speckled with purple defensive cells rich in alkaloids and astringent phenolic compounds.

Fermentation Transforms the Beans Cacao fermentation is a fermentation of the pulp, not the beans, but it transforms the beans as well. The acetic acid produced by the vinegar bacteria penetrates into the beans and etches holes in cells as it does so, spilling the contents of the cells together and allowing them to react with each other. The astringent phenolic substances mix with proteins, oxygen, and each other, and form complexes that are much less astringent. Most important, the beans' own digestive enzymes mix with the storage proteins and sucrose sugar and break them down into their building blocks - amino acids and simple sugars - which are much more reactive than their parent molecules, and will produce more aromatic molecules during the roasting process. Finally, the perforated beans soak up some flavor molecules from the fermenting pulp, including sugars and acids, fruity and flowery and winey notes. So a properly conducted fermentation converts the astringent but bland beans into vessels laden with desirable flavors and flavor precursors. Cacao fermentation is a fermentation of the pulp, not the beans, but it transforms the beans as well. The acetic acid produced by the vinegar bacteria penetrates into the beans and etches holes in cells as it does so, spilling the contents of the cells together and allowing them to react with each other. The astringent phenolic substances mix with proteins, oxygen, and each other, and form complexes that are much less astringent. Most important, the beans' own digestive enzymes mix with the storage proteins and sucrose sugar and break them down into their building blocks - amino acids and simple sugars - which are much more reactive than their parent molecules, and will produce more aromatic molecules during the roasting process. Finally, the perforated beans soak up some flavor molecules from the fermenting pulp, including sugars and acids, fruity and flowery and winey notes. So a properly conducted fermentation converts the astringent but bland beans into vessels laden with desirable flavors and flavor precursors.

Drying Once fermentation is complete, the cacao farmers dry the beans, often just by spreading them out on a flat surface in the sun. Drying can take several days, and if not done carefully can allow undesirable bacteria and molds to grow both on and within the beans and taint them with undesirable flavors. Once fermentation is complete, the cacao farmers dry the beans, often just by spreading them out on a flat surface in the sun. Drying can take several days, and if not done carefully can allow undesirable bacteria and molds to grow both on and within the beans and taint them with undesirable flavors.

Once dried to about 7% moisture, the beans are resistant to further microbial spoilage. They're then cleaned, bagged, and shipped to manufacturers all over the world.

Roasting Dried fermented cacao beans are less astringent and more flavorful than unfermented beans, but their flavor is still unbalanced and undeveloped, and often dominated by vinegary acetic acid. After selecting, sorting, and blending the dried beans, the chocolate manufacturer roasts them to develop their flavor. The time and temperature vary according to whether the beans are to be roasted whole, in their thin sh.e.l.l, or as the cracked inner kernels, the Dried fermented cacao beans are less astringent and more flavorful than unfermented beans, but their flavor is still unbalanced and undeveloped, and often dominated by vinegary acetic acid. After selecting, sorting, and blending the dried beans, the chocolate manufacturer roasts them to develop their flavor. The time and temperature vary according to whether the beans are to be roasted whole, in their thin sh.e.l.l, or as the cracked inner kernels, the nibs, nibs, or as nibs that have been ground into small, quickly heated particles. Whole beans take 3060 minutes at 250320F/ 120160C. This is a much gentler treatment than coffee beans require, thanks to the abundance of reactive amino acids and sugars that readily partic.i.p.ate in Maillard browning to generate flavor (p. 778). In fact, gentle roasting helps preserve some of the flavors that are intrinsic to the beans or developed during fermentation. or as nibs that have been ground into small, quickly heated particles. Whole beans take 3060 minutes at 250320F/ 120160C. This is a much gentler treatment than coffee beans require, thanks to the abundance of reactive amino acids and sugars that readily partic.i.p.ate in Maillard browning to generate flavor (p. 778). In fact, gentle roasting helps preserve some of the flavors that are intrinsic to the beans or developed during fermentation.

The Composition of Dried Fermented Cacao Beans

% by weight

Water

5 5.

Cacao b.u.t.ter

54 54.

Protein and amino acids

12 12.

Starch

6 6.

Fiber

11 11.

Sugars

1 1.

Phenolic compounds

6 6.

Minerals

3 3.

Theobromine

1.2 1.2.

Caffeine

0.2 0.2.

Grinding and Refining After roasting, the beans are cracked open and the nibs are separated from the sh.e.l.ls. The nibs are then pa.s.sed between several sets of steel rollers, and are transformed from solid chunks of plant tissue into a thick, dark fluid called cocoa liquor. This grinding stage has two purposes: to break the bean cells open and release their stores of cocoa b.u.t.ter; and to break the cells down into particles too small for the tongue to detect as separate, gritty grains. Because the nibs are around 55% cocoa b.u.t.ter, this fat becomes the continuous phase, and the solid fragments of the cells - mainly protein, fiber, and starch - are suspended in the fat. The final grinding, or refining, brings the particle size down to 0.020.03 mm. Swiss and German chocolates have traditionally been ground smoother than English and American. After roasting, the beans are cracked open and the nibs are separated from the sh.e.l.ls. The nibs are then pa.s.sed between several sets of steel rollers, and are transformed from solid chunks of plant tissue into a thick, dark fluid called cocoa liquor. This grinding stage has two purposes: to break the bean cells open and release their stores of cocoa b.u.t.ter; and to break the cells down into particles too small for the tongue to detect as separate, gritty grains. Because the nibs are around 55% cocoa b.u.t.ter, this fat becomes the continuous phase, and the solid fragments of the cells - mainly protein, fiber, and starch - are suspended in the fat. The final grinding, or refining, brings the particle size down to 0.020.03 mm. Swiss and German chocolates have traditionally been ground smoother than English and American.

Further treatment of the cocoa liquor varies according to the manufacturer's needs. To make cocoa powder and cocoa b.u.t.ter, the liquor is pressed through a fine filter that retains the cocoa particles while allowing the b.u.t.ter to flow through. The compacted cake of cocoa particles is then made into cocoa powder (below), while the b.u.t.ter becomes an important ingredient in all kinds of manufactured chocolate.

Conching Pure cocoa liquor has a concentrated chocolate taste, and may be hardened and packaged as is for use in baked goods. But its flavor is relatively rough, bitter, and astringent and acidic. To make it into something not only edible but delicious, manufacturers add a few other ingredients: sugar for dark chocolate, sugar and dry milk solids for milk chocolate, some vanilla (the whole bean, or an extract, or artificial vanillin), and a supplement of pure cocoa b.u.t.ter. And they subject the mixture to an extended agitation called Pure cocoa liquor has a concentrated chocolate taste, and may be hardened and packaged as is for use in baked goods. But its flavor is relatively rough, bitter, and astringent and acidic. To make it into something not only edible but delicious, manufacturers add a few other ingredients: sugar for dark chocolate, sugar and dry milk solids for milk chocolate, some vanilla (the whole bean, or an extract, or artificial vanillin), and a supplement of pure cocoa b.u.t.ter. And they subject the mixture to an extended agitation called conching, conching, a process named after the sh.e.l.l-like shape of the first machines. Conches rub and smear the mixture of cocoa liquor, sugar, and milk solids against a solid surface. The combination of friction and supplemental heat raises the temperature of the ma.s.s to 115175F/4580C (milk chocolate is kept at 110135F/4357C). Depending on the machine and manufacturer, conching may last for 8 to 36 hours. a process named after the sh.e.l.l-like shape of the first machines. Conches rub and smear the mixture of cocoa liquor, sugar, and milk solids against a solid surface. The combination of friction and supplemental heat raises the temperature of the ma.s.s to 115175F/4580C (milk chocolate is kept at 110135F/4357C). Depending on the machine and manufacturer, conching may last for 8 to 36 hours.

Refining Texture and Flavor The original conche was a mechanized version of the Mayan stone grinding slab: a heavy granite roller moved back and forth over a granite bed, both mixing the ingredients together and grinding the still somewhat coa.r.s.e particles to a finer size. Today the various solids are ground to the proper dimensions before conching, which now serves two main functions. First, it breaks up small aggregates of the solid particles, separates them from each other, and coats all of them evenly with cocoa b.u.t.ter, so that when the finished chocolate melts, it flows smoothly. Second, conching greatly improves the flavor of the chocolate, not by heightening it, but by mellowing it. The aeration and moderate heat causes as much as 80% of the volatile aromatic compounds (and excess moisture) to evaporate out of the chocolate liquor. Fortunately, many of these are undesirable volatiles, including various acids and aldehydes; acidity steadily declines during conching. At the same time, a number of desirable volatiles are augmented by the heat and mixing, notably those with roasted, caramel, and malty aromas (pyrazines, furaneol, maltol). The original conche was a mechanized version of the Mayan stone grinding slab: a heavy granite roller moved back and forth over a granite bed, both mixing the ingredients together and grinding the still somewhat coa.r.s.e particles to a finer size. Today the various solids are ground to the proper dimensions before conching, which now serves two main functions. First, it breaks up small aggregates of the solid particles, separates them from each other, and coats all of them evenly with cocoa b.u.t.ter, so that when the finished chocolate melts, it flows smoothly. Second, conching greatly improves the flavor of the chocolate, not by heightening it, but by mellowing it. The aeration and moderate heat causes as much as 80% of the volatile aromatic compounds (and excess moisture) to evaporate out of the chocolate liquor. Fortunately, many of these are undesirable volatiles, including various acids and aldehydes; acidity steadily declines during conching. At the same time, a number of desirable volatiles are augmented by the heat and mixing, notably those with roasted, caramel, and malty aromas (pyrazines, furaneol, maltol).

Both cocoa b.u.t.ter and a small amount of the emulsifier lecithin (p. 802) are added to the chocolate ma.s.s toward the end of conching. The additional cocoa b.u.t.ter is necessary to provide sufficient lubrication for all the added sugar particles to make the mixture creamily fluid rather than pasty when it melts. The higher the ratio of sugar to ground nibs, the more added cocoa b.u.t.ter is required. Lecithin, whose use in chocolate dates to the 1930s, coats the sugar particles with the fat-like ends of its molecules and helps reduce the amount of cocoa b.u.t.ter needed to lubricate the particles; one part of lecithin replaces 10 parts of b.u.t.ter. It typically makes up 0.30.5% of chocolate weight.

Manufacturing Chocolate and Cocoa Cooling and Solidifying After conching, dark chocolate is essentially a warm fluid ma.s.s of cocoa b.u.t.ter that contains suspended particles of the original cacao beans and of sugar. Milk chocolate also contains b.u.t.terfat, milk proteins, and lactose, and proportionally less cacao bean solids. After conching, dark chocolate is essentially a warm fluid ma.s.s of cocoa b.u.t.ter that contains suspended particles of the original cacao beans and of sugar. Milk chocolate also contains b.u.t.terfat, milk proteins, and lactose, and proportionally less cacao bean solids.

The last step in manufacturing chocolate is to cool the fluid chocolate to room temperature and form the familiar solid bars. It turns out that this transition from fluid to solid is a tricky one. To obtain stable cocoa b.u.t.ter crystals and a glossy, snappy chocolate, manufacturers carefully cool and then rewarm the liquid chocolate to particular temperatures before portioning it into molds, where it finally cools to room temperature and solidifies.

Cooks often melt manufactured chocolate in order to give it a special shape or to coat other foods. If they want it to resolidify with its original gloss and snap, then they must repeat in the kitchen this cycle of warming up and cooling down, or tempering tempering (p. 709). (p. 709).

The composition of dark and milk chocolates. Left: Left: Dark chocolate consists of cacao-bean particles and sugar crystals embedded in a base of cocoa b.u.t.ter. Dark chocolate consists of cacao-bean particles and sugar crystals embedded in a base of cocoa b.u.t.ter. Right: Right: In milk chocolate, a significant proportion of cacao-bean particles is replaced with particles of dried milk protein and sugar. In milk chocolate, a significant proportion of cacao-bean particles is replaced with particles of dried milk protein and sugar.

OPPOSITE: Making chocolate. As is true of cane sugar, chocolate is processed in two stages, the first in the tropical cacao-growing countries and the second in manufacturing plants throughout the world. Making chocolate. As is true of cane sugar, chocolate is processed in two stages, the first in the tropical cacao-growing countries and the second in manufacturing plants throughout the world.

The Special Qualities of Chocolate Consistency and Appearance: The Creations of Cocoa b.u.t.ter The remarkable appearance and consistency of chocolate are a direct expression of the physical qualities of cocoa b.u.t.ter, the part of chocolate that surrounds the solid particles of cacao bean and holds them together. When carefully prepared, chocolate has a silken or gla.s.sy surface, is hard and not greasy at room temperature, breaks with a delightful snap, yet melts to a smooth creaminess in the mouth. These are very unlike the qualities of any other food, and are a consequence of the structure of cacao fat molecules, which are mostly saturated and unusually regular (most of them are constructed from just three kinds of fatty acids). This structure means that the fat molecules are capable of forming a dense network of compact, stable crystals, with little liquid fat left over to ooze out between the crystals. The remarkable appearance and consistency of chocolate are a direct expression of the physical qualities of cocoa b.u.t.ter, the part of chocolate that surrounds the solid particles of cacao bean and holds them together. When carefully prepared, chocolate has a silken or gla.s.sy surface, is hard and not greasy at room temperature, breaks with a delightful snap, yet melts to a smooth creaminess in the mouth. These are very unlike the qualities of any other food, and are a consequence of the structure of cacao fat molecules, which are mostly saturated and unusually regular (most of them are constructed from just three kinds of fatty acids). This structure means that the fat molecules are capable of forming a dense network of compact, stable crystals, with little liquid fat left over to ooze out between the crystals.

However, this special network only develops when the fat crystallization is carefully controlled. Cocoa b.u.t.ter can solidify into six different kinds of fat crystals! Only two are stable kinds that produce a glossy, dry, hard chocolate; the other four are unstable kinds that produce a looser, less organized network, with more liquid fat, and crystals whose fat molecules readily detach and ooze away. When chocolate melts and then resolidifies in an uncontrolled way - for example, when it's temporarily left too close to a hot stove, or in a hot car - it's the unstable crystals that predominate, and they produce a greasy, soft, mottled chocolate. To rescue its original consistency, such chocolate must be tempered.

The crystallization of cocoa b.u.t.ter. Left: Left: In melted chocolate, the fat molecules (p. 798) of cocoa b.u.t.ter are in constant random motion. In melted chocolate, the fat molecules (p. 798) of cocoa b.u.t.ter are in constant random motion. Center: Center: When chocolate cools in an uncontrolled way, the fat molecules form loosely packed, unstable crystals, and the chocolate is soft and greasy. When chocolate cools in an uncontrolled way, the fat molecules form loosely packed, unstable crystals, and the chocolate is soft and greasy. Right: Right: When chocolate is carefully cooled, its fat molecules form tightly packed, stable crystals, and the chocolate is snappy and dry. When chocolate is carefully cooled, its fat molecules form tightly packed, stable crystals, and the chocolate is snappy and dry.

Chocolate Flavor Chocolate has one of the richest and most complex flavors of any food. In addition to its slight acidity, p.r.o.nounced bitterness and astringency, and the sweetness of its added sugar, chemists have detected more than 600 different kinds of volatile molecules in chocolate. While a handful of these may account for the basic roasted quality, many others contribute to its depth and wide range. The richness of chocolate flavor arises from two factors. One is the cacao bean's intrinsic flavor potential, its combination of sugars and proteins, and the enzymes that break these down into the building blocks of flavor. The second factor is the complexity of chocolate's preparation, which combines the chemical creativity of microbes and of high heat. Chocolate has one of the richest and most complex flavors of any food. In addition to its slight acidity, p.r.o.nounced bitterness and astringency, and the sweetness of its added sugar, chemists have detected more than 600 different kinds of volatile molecules in chocolate. While a handful of these may account for the basic roasted quality, many others contribute to its depth and wide range. The richness of chocolate flavor arises from two factors. One is the cacao bean's intrinsic flavor potential, its combination of sugars and proteins, and the enzymes that break these down into the building blocks of flavor. The second factor is the complexity of chocolate's preparation, which combines the chemical creativity of microbes and of high heat.

Among the flavors that an attentive taster can detect in chocolate are these: From the bean itself, astringency and bitterness (phenolic compounds, theobromine) From the fermented pulp, the flavors of fruits and wine and sherry and vinegar (acids, esters; alcohols; acetaldehyde; acetic acid) From the self-digested bean, almond and dairy and flowery notes (benzaldehyde; diacetyl and methyl ketones; linalool) From roasting and the browning reactions, roasted, nutty, sweet, earthy, flowery, and spicy notes (pyrazines and thiazoles; phenyls; phenylalka.n.a.ls; dienals), as well as a more p.r.o.nounced bitterness (diketopiperazines) From added sugar and vanilla, sweetness and the warm character of the spice From added milk solids, caramel and b.u.t.terscotch and cooked-milk and cheese notes Chocolate made from poorly fermented or handled beans can have a variety of unpleasant aromas, among them rubbery, burned, smoky, hammy, fishy, moldy, cardboard, and rancid notes.

Some confectioners add a small amount of salt to their products, especially milk chocolates. Saltiness is the one basic taste sensation missing from simply sweetened chocolate, and adding it is said to give the overall flavor a certain bite and clarity.

The Different Flavors of Milk ChocolateThe milk chocolates made in Europe, England, and the United States have traditionally had distinct flavors. In continental Europe, where it was invented, milk chocolate is made using dried whole milk powder, which has a relatively fresh milk flavor. In England, the preference has been to mix liquid milk with sugar, concentrate the mixture to 90% solids, mix it with chocolate liquor, and finish drying it into a material called "chocolate crumb." The milk proteins and sugars undergo browning reactions during the concentration and drying and produce a special cooked-milk, caramelized flavor that isn't obtained by ordinary drying. And in the United States, large manufacturers have long encouraged their milk fat to undergo some breakdown by fat-digesting enzymes. This breakdown develops a slight note of rancidity, whose cheesy, animal overtones blend well in their own way with chocolate flavor and make a positive contribution to the complexity of flavor.

The Kinds of Chocolate Manufacturers produce a wide range of different chocolates, some meant for eating as is, some meant for cooking or confectionery, some for all three. They fall into several general categories.

Ma.s.s-produced, inexpensive chocolates are made from ordinary beans that are processed in largely automated plants, and contain the minimum amount of cocoa solids and cocoa b.u.t.ter and the maximum amounts of sugar and milk solids. Their flavor is mild and unremarkable.

"Fine" expensive chocolates are made from beans selected for their excellent flavor potential, often processed in small batches to optimize flavor development, and contain far more than the minimum amount of cocoa solids and cocoa b.u.t.ter. Their flavor is stronger and more complex.

Dark chocolate contains cocoa solids, cocoa b.u.t.ter, and sugar, but no milk solids. It is manufactured in a range of compositions, from sugarless bitter bitter, to bittersweet bittersweet, to sweet. sweet. Some manufacturers now label their premium chocolates with their content of cocoa beans: "70% chocolate" is 70% by weight cocoa b.u.t.ter and cocoa solids, and about 30% sugar; "62% chocolate" is about 38% sugar (there are also small amounts of lecithin and vanilla). The higher the proportion of cocoa solids, the more intense the chocolate flavor, including its bitterness and astringency. Strong chocolates deliver more flavor to cream, egg, and flour mixtures, whose proteins bind to the phenolic substances and reduce the apparent astringency. Some manufacturers now label their premium chocolates with their content of cocoa beans: "70% chocolate" is 70% by weight cocoa b.u.t.ter and cocoa solids, and about 30% sugar; "62% chocolate" is about 38% sugar (there are also small amounts of lecithin and vanilla). The higher the proportion of cocoa solids, the more intense the chocolate flavor, including its bitterness and astringency. Strong chocolates deliver more flavor to cream, egg, and flour mixtures, whose proteins bind to the phenolic substances and reduce the apparent astringency.

Milk chocolate is the most popular form of chocolate, and the mildest. It contains milk solids and a large proportion of sugar, which together usually outweigh the combination of cocoa solids and cocoa b.u.t.ter. Thanks to its relatively low cocoa b.u.t.ter content, milk chocolate tends to be softer and less snappy than bittersweet chocolate.

Couverture chocolate (from the French for "to cover") is dark or milk chocolate formulated to flow easily when melted, and therefore to work well for forming thin, delicate chocolate coatings. This means adding more cocoa b.u.t.ter than usual to provide plenty of room for the cocoa and sugar particles to move past each other. Most couvertures are 3138% fat.

"White chocolate" is chocolate-less chocolate: it contains no cocoa particles whatsoever, and therefore has little or no chocolate flavor. White chocolate was invented around 1930, and is a mixture of purified, usually deodorized cocoa b.u.t.ter, milk solids, and sugar. It does offer a valuable decorative contrast to ordinary chocolate.

Some manufacturers are now packaging nibs, or small pieces of the roasted beans, which offer crunchy particles of intense flavor. Whole roasted beans can sometimes be found in Latin markets.

The Composition of Some Kinds of ChocolateChocolates vary widely in composition, especially among "bittersweet" and "semisweet" versions. The figures below, which are given in percent of the chocolate weight, are very approximate, but useful for broad comparisons.

Minimum cocoa solids + added cocoa b.u.t.ter, U.S.

Cocoa liquor Cocoa liquor

Unsweetened

99 99.

Bittersweet/semisweet 35 35.

7035 7035

Sweet (dark) 15 15.

15 15.