Chocolate facts and figures

Courtesy of Peter's Chocolate

Ecole Chocolat Note: This is a good introduction to chocolate facts and specifications from a commercial perspective – it disappeared from the Peter's site so I've included a copy here.

STANDARDS OF IDENTITIES
FDA-mandated standards of identities for the cocoa-derived products and other commonly used cocoa-based products. Several chocolates will claim a certain "percent cocoa solids." While this may not have a legal definition, for most manufacturers it generally means the total of all cocoa ingredients — cocoa butter, chocolate liquor, and cocoa powder.

CHOCOLATE TEMPERING AND METHODS USED
Tempering is often an essential stop before chocolate is used in food applications. Tempering is the controlled cooling of melted chocolate that promotes the formation of small, stable fat crystals in the finished product. Agitation, temperature and time affect it. Stable cocoa-butter crystals provide properties desired (Table III) in finished products. There are 4 - 6 forms of cocoa butter crystals that have different characteristics, melting points, and stability. Our aim is to provide conditions that grow "good" fat crystals and minimize the "bad" fat crystals. Tempering can be accomplished by several different methods (discussed below).

STABLE CRYSTAL CHARACTERISTICS

• Provide snap
• Provide good gloss
• Provide proper texture
• Are bloom-resistant
• Provide contraction for de-molding
• Are less permeable (shelf-life)

Mush method (tabliering)
Chocolate is heated to 110° - 115º to melt all seed crystals. This can be done in a microwave or a double boiler. Approximately two-thirds of this mass is poured onto a cold slab where it is worked and scraped until seed crystals form (approximately 79° - 80ºF). This mass is then returned to the remaining chocolate (95° - 105º F) and stirred gently until it reaches 84° - 86ºF. Generally, dark chocolate temperatures are about 2ºF higher than milk chocolate when tempering.

Chunk method
Coating is heated to 110° - 115ºF and chunks of tempered chocolate are added. The addition of the chocolate and stirring will gradually reduce the temperature to 86ºF (milk chocolate) to 86ºF (dark chocolate). Chunks must remain in the melted chocolate to this temperature to provide proper tempering. Unmelted pieces of chocolate are removed, and the melted chocolate and agitation will "seed" the coating. In the same manner, 4 - 5% of finally chopped or shaved chocolate can be added to 91° - 92ºF chocolate to facilitate rapid tempering.

Drip feed
For a production line that constantly uses chocolate such as for enrobing (discussed later), this method may be used effectively. A small steady flow of untempered chocolate (90° - 96ºF) equaling the rate of consumption is added to the tempered chocolate. The tempered chocolate will "seed" the incoming coating. Approximately 2 pounds of tempered chocolate should be maintained for every pound used in production. Exact rates and temperature will depend on the operation.

Direct method (microwave)
In this method, well-tempered chocolate is carefully melted (often in a microwave) until it reaches but does not exceed 90° - 91ºF. The chocolate must be stirred on a regular basis for proper heat distribution and to prevent burning. In a microwave, white and milk chocolate will burn more easily than dark chocolate and may require a reduced power setting for the microwave. When tempering chocolate in a microwave, use a container that will not get hot when microwaved: plastic containers are preferred over glass Pyrex bowls. This method can also be used with a double boiler and other similar melting methods.

Ecole Chocolate Note: While the direct method seems pretty darn easy (just melt the chocolate carefully) I've tried, but haven't had any luck, in perfecting this technique. It is very hard to get the whole mass of chocolate to melt and be warm enough to use for enrobing or molding while keeping the temperature under 90ºF. Give it a try and hopefully you'll be more successful than I have been.

Automated tempering
Whether done on an automated tempering unit or manually, the principles are the same. Melted chocolate (110° - 115ºF) is cooled to approximately 82° - 84ºF while being agitated for the formation of seed crystals. The temperature is then raised to 86° - 88ºF to prevent over-tempering and end up with the most stable cocoa-butter crystals available. Exact temperature and procedures depend on equipment and type of chocolate used. Four common types of automated temperers are used — tempering kettle, plate heat exchanger, screw-type temperer and bowl-type temperer. Having shiny, hard, glossy finished products is a good indication that chocolate is well tempered; temper-measuring machines are also available to help assess tempering. For individuals who do not have access to these machines, there is a simple method to determine temper in chocolate (as below):

• Take a metal spatula (or knife blade) and dip it in the chocolate that is hopefully in temper — leave only a thin film
• Place the spatula in a cool room (65 – 70ºF)
• Observe the time required for the chocolate to harden to the touch (set-up timing)
• Set-up timings can be interpreted as follows:
  < 2 minutes: Over tempered; may have less than optimal gloss
  4 - 6 minutes: Good temper; good gloss
  7 - 9 minutes: May still have a soft texture; under tempered; good gloss; may bloom in 1 - 2 months
  > 10 minutes: Little or no temper; poor gloss; presence of bloom

DEPOSITING AND MOLDING CHOCOLATE

Drop depositing
This operation is used for the production of retail "chocolate chips" and "caps" (buttons); these are used in many bakery products because of easier handling and melting. For this operation, tempered chocolate is deposited via a multi-piston block, through a depositor plate and nozzle, onto a moving belt. This belt will pass through a cooling tunnel and return to the depositing station after the product has been removed. Production of caps involves depositing the chocolate on a belt or into molds. While these are easier to handle and melt, they have the disadvantage of being more expensive and more sensitive to odor and moisture pickup due to increased surface area.

Solid molding
This operation ranges from small novelty items and retail bars to 10-lb. blocks commonly used in the food industry. Tempered chocolate is deposited into metal or increasingly used polycarbonate moulds that are a reverse image of the desired end product. Inclusions such as nuts, raisins, etc. are added to the chocolate just prior to the depositing step. After the chocolate has hardened and contracted, the moulds are inverted and tapped to remove product. The moulds will be warmed to the proper temperature before returning to the depositor to avoid blooming problems.

Shell molding
This is generally a 3-step operation in which a center confection is enclosed in a chocolate shell. Unlike "enrobing," which also encases a center in chocolate, soft centered confections such as flowing caramel can be used. Essentially, a good part of the filled chocolate in a mould is shaken out such that the remaining chocolate in the mould serves as the shell for the confection. There has been a recent trend to use a one-shot depositor instead of a 3-stage moulding plant.

Hollow molding
In this operation, most commonly associated with chocolate Easter bunnies, a 2-piece mould is opened for the proper deposit amount of tempered chocolate, then closed and rapidly rotated while being cooled. The spinning action will insure an even coat of chocolate on the inside of the mould. After adequate cooling, the mould is opened and the product removed.

MAJOR ATTRIBUTES OF CHOCOLATE

Appearance
Visual appeal is quite important since 80% of our tasting is done through our eyes. While it is generally believed that dutch chocolate tastes stronger because of its darker color, it in fact has a milder flavor. Color of chocolate can be affected by formulation, type of beans, dutching and degree of roast. Increasing the amount of chocolate liquor in a formula will give a more flavorful, darker color.

The dutching process will yield a darker color but can be controlled by adjusting time, temperature, concentration of alkali, moisture, and the type of alkalization material used. Also, the substance being dutched will determine color intensity; generally, color intensity is low in dutching whole bean and increases progressively in going to nibs, liquor, and cocoa powder. This is due to increasing penetration of the alkali solution and final pH of the product. For bakery items, dutch cocoa is generally used for products leavened with baking powder while formulations with baking soda uses natural cocoa. Roast time and temperature will also affect product color; with an increase in time and temperature yielding a darker color. Final product particle size also affects color perception. Color comparison can be done several ways, including the use of colorimeters. The easiest and most simple is to place melted product next to the "control" sample on a glass plate. When viewed from the underside, cast and color differences can easily be seen. The flavor beans (Criollo) will have a lighter color than the base beans (Forastero). The fermentation process used and seasonality will also affect the pigmentation in the beans.

Mouth-feel and smoothness
Particle size of the chocolate is most important in the mouthfeel and whether it is perceived as gummy, creamy, or gritty. Most particle sizes of coatings range from 10 - 40 microns (µm). The particle size of chocolate being measured is usually that of the sugar it contains since the liquor solids are ground extremely fine to release all available fat. Most individuals will generally not detect particle size smaller than 25 µm, which is important if a smooth mouth-feel is desired.

Coarser particle coatings may be acceptable if inclusions such as crisp rice and nuts will take away any smoothness advantage. Very fine grade coatings will need an increase in available free fat or the smooth, creamy texture may become gummy due to the increased surface area that needs to be lubricated. Particle size can be measured by different methods but most popular is the micrometer because of its simplicity and low coat.

Viscosity
Viscosity, often given in degrees of MacMichel (Brookfield instrument) and rheology, are important to the confectioner and baker on how the chocolate handles; different uses will require different handling properties. Viscosity will generally tell the thickness or thinness of chocolate; as the viscosity number becomes smaller, the chocolate viscosity will become thinner.

Viscosity alone will, however, not tell how the product will handle. Two terms that help to describe flow character are "yield value" and "plastic value." Yield value is the force required to start the flow of the chocolate; plastic value is the force required to keep the chocolate flowing once it has started to move. A high-yield value is important in maintaining decoration marks and the prevention of "feet" on enrobed goods. A low-yield value is desired in moulding (especially with inclusions) so that they will properly shake out and leave a few air pockets.

SELECTION OF CHOCOLATE

(FLAVOR CONSIDERATION)

The flavor of a chocolate is often a personal choice that should compliment the finished products being manufactured. Coatings should be free of off-odors and flavors and should balance the flavor profile of the finished items. A very sweet center of a product will usually be complimented by a bittersweet chocolate while a mild, subtle center will be highlighted by a mild-flavored coating. Tasting of individual samples of pure chocolate may help to narrow the choices from a vast array of available coatings. Final selection, however, will probably require a completely finished product that incorporates the selected chocolate for proper evaluation and optimum flavor. Chocolate selection must factor in customer's input and suggestions. In producing a variety of finished products, various recipes and formulations may call for a number of chocolate-based products. Not all may be available. Table IV lists information on approximate substitutions that can be made.

CHOCOLATE BLOOMING PROBLEMS

Other than cost, the blooming of chocolate is probably the most common problem encountered. Fat bloom is the visible accumulation of large cocoa butter crystals on the chocolate surface. It is often accompanied by numerous mini cracks that also give a dull appearance.

Sugar bloom is a crystallization of sugar that is often caused by high humidity and the formation of condensate (sweating) when cold product is brought into a warm area. Wiping the outer surface will generally remove fat bloom while sugar will remain.

While poor tempering often causes bloom, it can also be caused by improper cooling, poor storage conditions, high humidity, etc. Table V lists these and other potential causes of blooming. Fat incompatibilities can often be a cause of bloom. Oils from the center mass can migrate to the chocolate shell to cause it to soften and bloom. Chocolates and compound coatings should not usually be mixed for this reason.

CHOCOLATE SUBSTITUTION PRODUCTS

Cocoa (1 pound): Substitute with 2 lb. chocolate liquor and remove 1 lb. of oil/fat from the formula

Chocolate Liquor (1 pound):
- Substitute with 0.5 lb. cocoa + 0.5 lb. fat/oil or
- Substitute with 2 lb. bittersweet chocolate (remove 1 lb. sugar from formula)

Bittersweet Chocolate (1 pound):
- Substitute with 0.75 lb. semisweet chocolate + 0.25 lb. chocolate liquor or
- Substitute with 0.5 lb. chocolate liquor + 0.5 lb. sugar or
- Substitute with 3 lb. milk chocolate and remove 1 lb. sugar, 0.5 lb. milk and 0.5 lb.fat/oil from the formula

Milk Chocolate (1 pound):
- Substitute with 0.33 lb. semisweet chocolate + 2 ounces powdered milk + 0.33 lb. sugar + 3 ounce fat/oil

It is important to make most temperature changes gradually and to not shock the chocolate. When chocolate is being cooled, it should be done gradually not only to prevent bloom but also a skinning effect. This "skin" will insulate the interior chocolate and may cause dulling as it contracts. The beginning of a cooling tunnel should have minimal air movement and a relatively warm temperature of approximately 65ºF. Temperature can gradually be decreased to about 55ºF with increasing air velocity. Before exiting the cooling tunnel, temperature should approach that of the packing room (68ºF). While the chocolate may appear solid at the end of the cooling tunnel, only about 70 - 75% of the coating is crystallized. It will take about 48 hours for all of the chocolate to crystallize, so packing and storage conditions are still potential sources of abuse.

Contrary to popular belief, it is possible to have bloom on compound coatings. Using the coatings at too high a temperature usually causes this. The proper temperature is usually 5ºF higher than the melt point of the main fat constituents of the coating. Most commonly, this translates to approximately 100° - 105ºF. The supplier of the coatings can provide more specific information. When cooling coatings, a rapid cooling at 45° - 50ºF is better and will provide less blooming than the warmer conditions used for chocolate. When well tempered and properly stored, compound coating will be bloom-free for 6 - 9 months, and chocolates for several years.

SOME FACTORS CAUSING CHOCOLATE BLOOMING AND DULL FINISH

• Extreme water temperature used in cooling/heating
• Cooling tunnels/rooms that are extremely cold
• Cold moulds (warm to 75° - 80ºF)
• Products removed from cold storage to room temperature: not done in steps to prevent condensation
• Erratic temperature fluctuations during storage
• Storage temperatures that exceed 88° - 90ºF will cause melting and bloom (the closer we approach this limit, the greater the likelihood of fat bloom; ideal temperature: 68ºF or less)
• Cold center mass when enrobing (ideal temperature is 70° - 75ºF)
• Formation of condensate in cooling tunnel
• Improper formulation of centers that allow moisture or oils to migrate to the outer surface of the coating
• Packaging/shrink-wrap of finished goods with heat can cause localized bloom

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