On Food And Cooking Part 86

Milk 10 10.

10 10.

Unsweetened cocoa powder

Added cocoa b.u.t.ter Sugar Sugar

Unsweetened 0 0.

0 0.

Bittersweet/semisweet 015 015 3050 3050

Sweet (dark) 20 20.

60 60.

Milk 20 20.

50 50.

Unsweetened cocoa powder

Milk solids Total fat Total fat

Unsweetened 0 0.

53 53.

Bittersweet/semisweet 0 0.

2538 2538

Sweet (dark) 0 0.

32 32.

Milk 15 15.

30 30.

Unsweetened cocoa powder

20 20.

Total carbohydrates Protein Protein

Unsweetened 30 30.

13 13.

Bittersweet/semisweet 4565 4565 46 46

Sweet (dark) 72 72.

2 2.

Milk 60 60.

8 8.

Unsweetened cocoa powder 40 40.

15 15.

Storing Chocolate; Fat Bloom The best storage temperature for chocolate is a constant 6065F/1518C, without fluctuations that would encourage the melting and recrystallization of the cocoa b.u.t.ter fats. Sometimes stored chocolate will develop a white, powdery-looking coating on its surface. This "fat bloom" is cocoa b.u.t.ter that has melted out of unstable crystals, migrated to the surface, and formed new crystals there. Fat bloom is normally prevented by proper tempering of the chocolate in the first place. Its development can be slowed down by the addition to the melted chocolate of some clarified b.u.t.ter, which makes the mix of fats more random and so r.e.t.a.r.ds the formation of crystals. The best storage temperature for chocolate is a constant 6065F/1518C, without fluctuations that would encourage the melting and recrystallization of the cocoa b.u.t.ter fats. Sometimes stored chocolate will develop a white, powdery-looking coating on its surface. This "fat bloom" is cocoa b.u.t.ter that has melted out of unstable crystals, migrated to the surface, and formed new crystals there. Fat bloom is normally prevented by proper tempering of the chocolate in the first place. Its development can be slowed down by the addition to the melted chocolate of some clarified b.u.t.ter, which makes the mix of fats more random and so r.e.t.a.r.ds the formation of crystals.

Thanks to its abundant antioxidant molecules and chemically stable saturated fats, chocolate has a remarkably long shelf life. It keeps for many months at room temperature. White chocolate, which lacks the antioxidants in the cocoa solids, has a room-temperature shelf life of only a few weeks; after that, or sooner if it's exposed to bright light, its fats are damaged and it develops a stale, rancid flavor.

Cocoa Powder Manufacturers produce cocoa powder from the cakes of roasted cocoa bean particles left behind when they extract cocoa b.u.t.ter (p. 699). The particles remain coated with a thin layer of cocoa b.u.t.ter; the fat content of the powder ranges from 8 to 26%. The solid particles of the cacao bean are the source of chocolate's flavor and color. Cocoa is therefore the most concentrated version of chocolate, and a valuable ingredient in its own right. Natural cocoa powder has a strong chocolate taste and p.r.o.nounced astringency and bitterness. It's also distinctly acid, with a pH around 5. Manufacturers produce cocoa powder from the cakes of roasted cocoa bean particles left behind when they extract cocoa b.u.t.ter (p. 699). The particles remain coated with a thin layer of cocoa b.u.t.ter; the fat content of the powder ranges from 8 to 26%. The solid particles of the cacao bean are the source of chocolate's flavor and color. Cocoa is therefore the most concentrated version of chocolate, and a valuable ingredient in its own right. Natural cocoa powder has a strong chocolate taste and p.r.o.nounced astringency and bitterness. It's also distinctly acid, with a pH around 5.

"Dutched" or Alkalized Cocoa In Europe and sometimes the United States, cocoa powder is produced from cocoa beans that have been treated with an alkaline substance, pota.s.sium carbonate. This treatment, sometimes called "dutching" because its inventor was the Dutch chocolate pioneer Conrad van Houten, raises the cocoa pH to a neutral 7 or alkaline 8. The application of an alkaline material to the beans either before or after roasting has a strong influence on their general chemical composition. In addition to adding a distinctly alkaline taste (like that of baking soda), alkaline treatment reduces the levels of roasty, caramel-like molecules (pyrazines, thiazoles, pyrones, furaneol) and of astringent, bitter phenolics, which now bond to each other to form flavorless dark pigments. The result is a cocoa powder with a milder flavor and darker color. Dutched cocoa can be produced in shades running from light brown to nearly black; the darker the color, the milder the flavor. In Europe and sometimes the United States, cocoa powder is produced from cocoa beans that have been treated with an alkaline substance, pota.s.sium carbonate. This treatment, sometimes called "dutching" because its inventor was the Dutch chocolate pioneer Conrad van Houten, raises the cocoa pH to a neutral 7 or alkaline 8. The application of an alkaline material to the beans either before or after roasting has a strong influence on their general chemical composition. In addition to adding a distinctly alkaline taste (like that of baking soda), alkaline treatment reduces the levels of roasty, caramel-like molecules (pyrazines, thiazoles, pyrones, furaneol) and of astringent, bitter phenolics, which now bond to each other to form flavorless dark pigments. The result is a cocoa powder with a milder flavor and darker color. Dutched cocoa can be produced in shades running from light brown to nearly black; the darker the color, the milder the flavor.

Chocolate Cools the MouthWell-made chocolate has an unusual and refres.h.i.+ng characteristic for such a rich food: as it melts, it cools the mouth. This happens because its stable fat crystals melt in a very narrow temperature range, and just below body temperature. The phase change from solid to liquid absorbs much of the mouth's heat energy and leaves little to raise the temperature of the chocolate, which therefore feels persistently cool.

Cocoas in Baking It's important for bakers to be aware of the difference between "natural" and alkalized cocoa powders. Some recipes rely on acidic natural cocoa to react with baking soda and generate leavening carbon dioxide. If the same recipe is made with an alkalized cocoa, the reaction won't take place, no carbon dioxide will be generated, and the taste will be alkaline and soapy. It's important for bakers to be aware of the difference between "natural" and alkalized cocoa powders. Some recipes rely on acidic natural cocoa to react with baking soda and generate leavening carbon dioxide. If the same recipe is made with an alkalized cocoa, the reaction won't take place, no carbon dioxide will be generated, and the taste will be alkaline and soapy.

Instant Cocoa So-called "instant" cocoas for hot chocolate include lecithin, an emulsifier that helps separate the particles so that they mix readily with water. Sugar is frequently added to instant cocoa mix and may account for up to 70% of its weight. So-called "instant" cocoas for hot chocolate include lecithin, an emulsifier that helps separate the particles so that they mix readily with water. Sugar is frequently added to instant cocoa mix and may account for up to 70% of its weight.

Chocolate and Cocoa as Ingredients Chocolate and cocoa are versatile ingredients. They're incorporated into many mixtures of ingredients, and not just sweets; savory Mexican mole sauces and some European meat stews and sauces borrow depth and complexity from them. Chocolate and cocoa provide flavor, richness, and structure-building capacity; their dry particles contain both starch and protein, absorb moisture, and contribute thickness and solidity to baked goods, souffles, fillings and icings. Flourless cakes can be made with chocolate or cocoa as the starchy and fatty ingredients, eggs as the moistening and setting agent. In a chocolate mousse, the foam structure provided by the whipped eggs is reinforced by both the dry particles and the gradually crystallizing cocoa b.u.t.ter.

Of course, chocolate can be presented as is, part of a pastry construction for example, or melted over a preparation and then hardened to provide a coating. It's when we melt and cool it for coating or molding that it requires the most care (p. 708). Otherwise, keeping in mind a few facts about chocolate will prevent most problems.

Working with Chocolate Dark chocolate is a fully cooked, fully developed ingredient in its own right, robust and forgiving. Remember that it has been roasted and then heated again to fairly high temperatures in the conche, and that it's a relatively simple physical mixture of cocoa and sugar particles in fat. The most that a cook needs to do to it is melt it to perhaps 120F/50C, but it can be heated to 200F/93C and then some without suffering disastrous effects. It won't separate, and it won't burn unless it's left over direct stovetop heat or in a microwave oven without stirring. It can be melted and solidified repeatedly if necessary. Dark chocolate is a fully cooked, fully developed ingredient in its own right, robust and forgiving. Remember that it has been roasted and then heated again to fairly high temperatures in the conche, and that it's a relatively simple physical mixture of cocoa and sugar particles in fat. The most that a cook needs to do to it is melt it to perhaps 120F/50C, but it can be heated to 200F/93C and then some without suffering disastrous effects. It won't separate, and it won't burn unless it's left over direct stovetop heat or in a microwave oven without stirring. It can be melted and solidified repeatedly if necessary.

Because they contain more milk solids than they do cocoa solids, milk chocolate and white "chocolate" are less robust than dark chocolate and are best melted gently.

Melting Chocolate Chocolate can be successfully melted in several different ways: quickly, over direct stove heat, with care and constant stirring to avoid burning; more slowly, but with less attention; in a bowl set over a pan of hot water, from 100F/38C to the simmer (the hotter the water, the faster it melts); in the microwave oven, with frequent interruptions for stirring and checking the temperature. Because chocolate is a poor heat conductor, it's best to chop it into small pieces or process it into crumbs to speed its melting, or its blending with hot ingredients. Chocolate can be successfully melted in several different ways: quickly, over direct stove heat, with care and constant stirring to avoid burning; more slowly, but with less attention; in a bowl set over a pan of hot water, from 100F/38C to the simmer (the hotter the water, the faster it melts); in the microwave oven, with frequent interruptions for stirring and checking the temperature. Because chocolate is a poor heat conductor, it's best to chop it into small pieces or process it into crumbs to speed its melting, or its blending with hot ingredients.

Chocolate and Moisture The one vulnerable aspect of chocolate is its extreme dryness, and the vast number of tiny sugar and cacao particles whose surfaces attract moisture. If a small amount of water is stirred into molten chocolate, the chocolate will seize up into stiff paste. It seems perverse that adding liquid to a liquid produces a solid: but the small amount of water acts as a kind of glue, wetting the many millions of sugar and cocoa particles just enough to make patches of syrup that stick the particles together and separate them from the liquid cocoa b.u.t.ter. It's important, then, either to keep chocolate completely dry, or to add enough liquid to dissolve the sugar into a syrup, not just wet it. It's therefore best to add solid chocolate to hot liquid ingredients, or pour the hot liquid all at once onto the chocolate, rather than add the liquid gradually to molten chocolate. Seized chocolate can be salvaged by adding more warm liquid until the paste turns into a thick fluid. The one vulnerable aspect of chocolate is its extreme dryness, and the vast number of tiny sugar and cacao particles whose surfaces attract moisture. If a small amount of water is stirred into molten chocolate, the chocolate will seize up into stiff paste. It seems perverse that adding liquid to a liquid produces a solid: but the small amount of water acts as a kind of glue, wetting the many millions of sugar and cocoa particles just enough to make patches of syrup that stick the particles together and separate them from the liquid cocoa b.u.t.ter. It's important, then, either to keep chocolate completely dry, or to add enough liquid to dissolve the sugar into a syrup, not just wet it. It's therefore best to add solid chocolate to hot liquid ingredients, or pour the hot liquid all at once onto the chocolate, rather than add the liquid gradually to molten chocolate. Seized chocolate can be salvaged by adding more warm liquid until the paste turns into a thick fluid.

Different Chocolates Are Not Interchangeable Both recipe writers and cooks need to be as precise as possible about the kinds of chocolate they use. Different chocolates have very different proportions of cocoa b.u.t.ter, cocoa particles, and sugar. The proportions of cocoa particles and sugar are especially important when chocolate is combined with wet ingredients. Sugar dissolves into syrup, thereby increasing the volume of a preparation's liquid phase and contributing fluidity, while cocoa particles absorb moisture, decrease the volume of the liquid phase, and reduce fluidity. A recipe developed for sweet chocolate may fail badly if it's made with a 70% premium bittersweet chocolate, which has far more drying cocoa particles and far less syrup-making sugar. Both recipe writers and cooks need to be as precise as possible about the kinds of chocolate they use. Different chocolates have very different proportions of cocoa b.u.t.ter, cocoa particles, and sugar. The proportions of cocoa particles and sugar are especially important when chocolate is combined with wet ingredients. Sugar dissolves into syrup, thereby increasing the volume of a preparation's liquid phase and contributing fluidity, while cocoa particles absorb moisture, decrease the volume of the liquid phase, and reduce fluidity. A recipe developed for sweet chocolate may fail badly if it's made with a 70% premium bittersweet chocolate, which has far more drying cocoa particles and far less syrup-making sugar.

Ganache Once of the simplest and most familiar of chocolate preparations is ganache, a mixture of chocolate and cream that can be infused with many other flavors, whipped to lighten its richness, or further enriched with b.u.t.ter. It serves as a filling for chocolate truffles and pastries, and as both filling and topping for cakes. The dessert called pot de creme, made by melting some chocolate into about twice its weight of cream, is essentially a ganache served on its own. Once of the simplest and most familiar of chocolate preparations is ganache, a mixture of chocolate and cream that can be infused with many other flavors, whipped to lighten its richness, or further enriched with b.u.t.ter. It serves as a filling for chocolate truffles and pastries, and as both filling and topping for cakes. The dessert called pot de creme, made by melting some chocolate into about twice its weight of cream, is essentially a ganache served on its own.

Ganache Structure A soft ganache is made with approximately equal weights of cream and chocolate. A firm ganache, more suitable for holding a shape and with a stronger chocolate flavor, is made with two parts chocolate for every one of cream. To make ganache, the cream is scalded and the chocolate melted into it to form a complex combination of an emulsion and a suspension (p. 818). The continuous phase of this mixture, the portion that permeates it, is a syrup made from the cream's water and the chocolate's sugar. Suspended in the syrup are the milk fat globules from the cream, and cocoa b.u.t.ter droplets and solid cocoa particles from the chocolate. A soft ganache is made with approximately equal weights of cream and chocolate. A firm ganache, more suitable for holding a shape and with a stronger chocolate flavor, is made with two parts chocolate for every one of cream. To make ganache, the cream is scalded and the chocolate melted into it to form a complex combination of an emulsion and a suspension (p. 818). The continuous phase of this mixture, the portion that permeates it, is a syrup made from the cream's water and the chocolate's sugar. Suspended in the syrup are the milk fat globules from the cream, and cocoa b.u.t.ter droplets and solid cocoa particles from the chocolate.

Food Words: Ganache GanacheThe word ganache ganache is French, and before it was applied to a mixture of chocolate and cream, it meant "cus.h.i.+on." The confectioner's ganache is indeed a kind of melting cus.h.i.+on for the mouth, soft and plush. Ganache seems to have been invented in France or Switzerland in the middle of the 19th century. Chocolate truffles, morsels of ganache shaped into rough b.a.l.l.s and coated either with cocoa powder or a thin layer of hard chocolate, were a simple homemade sweet until well into the 20th century, when they became fas.h.i.+onable luxuries. is French, and before it was applied to a mixture of chocolate and cream, it meant "cus.h.i.+on." The confectioner's ganache is indeed a kind of melting cus.h.i.+on for the mouth, soft and plush. Ganache seems to have been invented in France or Switzerland in the middle of the 19th century. Chocolate truffles, morsels of ganache shaped into rough b.a.l.l.s and coated either with cocoa powder or a thin layer of hard chocolate, were a simple homemade sweet until well into the 20th century, when they became fas.h.i.+onable luxuries.

In an even mixture of cream and chocolate, there's an abundance of the syrup phase to hold the fat and particles; but in a firm, high-chocolate mixture, there's less syrup, and proportionally more cocoa particles that slowly absorb moisture from the syrup and reduce its volume even further. With chocolates high in cocoa solids, the cocoa particles can eventually absorb so much moisture that they swell and stick to each other. The water-deprived emulsion then fails, allowing the fat globules and droplets to coalesce, and the fat to separate from the swollen particles. This is why high-chocolate ganaches are often unstable and coa.r.s.en with time.

Maturing Ganache Many confectioners let ganache mixtures stand at a cool room temperature overnight before working with them. This gradual cooling allows the cocoa b.u.t.ter to crystallize so that when the ganache is shaped or eaten, it softens and melts more slowly. Ganache refrigerated immediately after making hardens without forming many crystals, and becomes soft and greasy when it warms. Many confectioners let ganache mixtures stand at a cool room temperature overnight before working with them. This gradual cooling allows the cocoa b.u.t.ter to crystallize so that when the ganache is shaped or eaten, it softens and melts more slowly. Ganache refrigerated immediately after making hardens without forming many crystals, and becomes soft and greasy when it warms.

Thanks to the initial scalding of the cream and the chocolate's sugar content, moisture-absorbing cocoa particles, and abundant microbe-unfriendly phenolic compounds, ganache has a surprisingly long shelf life of a week or more at room temperature.

Tempered Chocolate for Coating and Molding Like sugar, chocolate can be shaped to please the eye. Pastry cooks and confectioners make thin chocolate sheets by brus.h.i.+ng melted chocolate onto a surface, then letting the chocolate set completely, and stamping or cutting it into shapes, or nudging it into a ruffle. Melted chocolate can be painted onto plant leaves, allowed to harden into the leaves' mirror images, then gently peeled off. It can be squeezed through a pastry bag and tip to form a myriad of lines, drops, and filled shapes. And of course it can be used to line molds and produce shapes from hollow spheres to Easter bunnies.

Chocolate lovers often melt chocolate and then use it as a coating for cookies or strawberries or handmade truffles. This can be done easily and casually, the chocolate simply warmed until it melts and then used immediately, the results sometimes chilled in the refrigerator to speed their solidification. Chocolate handled in this way will taste fine, but it's likely to look dull and mottled, and to be soft instead of snappy. This is because the chocolate cooled down so quickly that its cocoa fat solidified into a loose, weak network of unstable crystals instead of the dense, hard network of stable crystals. If appearance and consistency matter, as they do to professional cooks and confectioners, then the cook must temper temper the melted chocolate, or prime it with desirable stable crystals of cocoa fat, just as the manufacturer did before forming it into bars. the melted chocolate, or prime it with desirable stable crystals of cocoa fat, just as the manufacturer did before forming it into bars.

The structure of ganache. Left: Left: Soft ganache is made with an equal proportion of chocolate and cream, with cocoa particles and droplets of cocoa and milk fat surrounded by a syrup of the chocolate's sugar and the cream's water. Soft ganache is made with an equal proportion of chocolate and cream, with cocoa particles and droplets of cocoa and milk fat surrounded by a syrup of the chocolate's sugar and the cream's water. Center: Center: A firm ganache, made with more chocolate than cream, contains proportionally more dry cocoa particles and less water. A firm ganache, made with more chocolate than cream, contains proportionally more dry cocoa particles and less water. Right: Right: With time, the cocoa particles in a firm ganache absorb water from the syrup and swell. This can crowd the fat droplets so tightly that they coalesce and the ganache separates. With time, the cocoa particles in a firm ganache absorb water from the syrup and swell. This can crowd the fat droplets so tightly that they coalesce and the ganache separates.

Tempering Chocolate The tempering process consists of three basic steps: heating the chocolate to thoroughly melt all of its fat crystals, cooling it somewhat to form a new set of starter crystals, and carefully heating it again to melt the unstable crystals, so that only desirable stable crystals remain. The stable starter crystals will then direct the development of the dense, hard crystal network when the chocolate finally cools and solidifies. The tempering process consists of three basic steps: heating the chocolate to thoroughly melt all of its fat crystals, cooling it somewhat to form a new set of starter crystals, and carefully heating it again to melt the unstable crystals, so that only desirable stable crystals remain. The stable starter crystals will then direct the development of the dense, hard crystal network when the chocolate finally cools and solidifies.

Unstable cocoa b.u.t.ter crystals are crystals that melt relatively easily, which means at relatively cool temperatures, between about 59 and 82F/1528C. The desirable stable crystals (sometimes referred to as "beta" or "beta prime" or "Form V" crystals) melt only at warmer temperatures, between 89 and 93F/3234C. The temperature range in which a particular kind of crystal melts is also the range in which it forms forms as the chocolate cools. Unstable crystals therefore form when molten chocolate is cooled rapidly, so that the stable crystal types - the ones that begin to form at warmer temperatures - don't have time to gather most of the fat molecules to themselves before the unstable crystals begin to form. Stable crystals predominate in melted chocolate when the cook carefully holds it at temperatures as the chocolate cools. Unstable crystals therefore form when molten chocolate is cooled rapidly, so that the stable crystal types - the ones that begin to form at warmer temperatures - don't have time to gather most of the fat molecules to themselves before the unstable crystals begin to form. Stable crystals predominate in melted chocolate when the cook carefully holds it at temperatures above above the melting point of the unstable crystals, but the melting point of the unstable crystals, but below below the melting point of the stable crystals. This tempering range is 8890F/3132C for dark chocolate, somewhat lower for milk and white chocolates thanks to their mixture of cocoa and milk fats. the melting point of the stable crystals. This tempering range is 8890F/3132C for dark chocolate, somewhat lower for milk and white chocolates thanks to their mixture of cocoa and milk fats.

Temperatures for Tempering Different Kinds of ChocolateThe ideal temperatures for preparing milk and white chocolates depend on the formulation of the particular chocolate, and are best obtained from the manufacturer. This chart gives figures generally used in the chocolate industry.

Kind of Chocolate

Melting Temperature Melting Temperature

Dark

113122F/4550C 113122F/4550C

Milk

104113F/4045C 104113F/4045C

White

104F/40C 104F/40C.