Milk Chocolate Applications — Maintaining Quality and Solving Problems William Dyer Blommer Chocolate Company “quality” and “problem” as they apply to hocolate, to some consumers, is the Dyer joined Blommer Creward. It’s the ultimate indul- enjoying and using chocolate.As we’ll see, Chocolate Company in gence — truly a feel-good pacifier and it depends on whom you ask. 1996. He provides tech- In regard to quality, when you ask con- nical support in the use part, as some chocoholics claim, of an of chocolate, com- important food group. sumers, they’ll tell you their criteria are pounds and alkalized What’s not to love about chocolate? It appearance of the product, wonderful cocoa powders in a has a wonderful fragrance, delicious taste rich flavor, good eating quality, mouthfeel variety of applications. and smooth mouthfeel. But as appealing as and value. Dyer worked at Gill and Duffus Products, then chocolate is, it brings special quality and A candy manufacturer will cite all of the joined Durkee Indus- manufacturing challenges for producers of above and add a few others.These include trial Foods; through confections and baked goods. Why? the suitability of the chocolate in a partic- acquisition, Dyer was Because chocolate has some unique behav- ular application, the nature of ingredients transferred to Loders Croklaan. While there iors that need to be understood and man- to be combined and the cost and avail- he developed technical aged in order to produce the best prod- ability of the ingredients. Last, but not presentations to provide ucts possible. least, there’s shelf life and stability of the education about ingre- In this paper we’ll review some of the finished product. dient applications. challenges of chocolate issues from the per- The chocolate manufacturer must be spective of the “real world,” rather than from able to meet all of the candy manufactur- academic experiences and experiments.We ers’ needs and expectations, and duplicate will look at special considerations in select- them consistently batch after batch. Both ing and using chocolate.We’ll see how prob- the manufacturer of the chocolate and the lems occur when we incorrectly identify candy producer view these considerations process problems and their solutions. And, of quality in practical terms. we’ll evaluate some storage issues. Of course, some criteria are common to But first, we need to define the words the consumer, candy manufacturers and William Dyer 52nd P.M.C.A. Production Conference, 1998 137 Milk Chocolate Applications We must chocolate producers.These are the appear- in the chocolate recipe result in chocolates understand the ance, rich flavor and the structural integri- with richer flavor, but the chocolate user must interaction of a ty of the confection. In this business, of keep in mind that high milk content in the chocolate course, we translate these attributes into chocolate will result in a higher percentage of coating with the our own, more familiar terms. milk fat in the total fat phase. The emphasis confection’s • Where the consumer says “appearance,” here is on percentage of milk fat because we center during we may say “initial gloss,” “gloss reten- know that trace amounts of milk fat in choco- tion” and “bloom stability.” manufacturing, late prevent bloom in finished products, but • Rich flavor becomes the “flavor release shipping and higher levels of milk fat will result in limiting of the product.” shelf life. functional attributes of chocolate. • And, structural integrity means the touch Cocoa butter’s sensitivity to high levels of stability of the product, as well as its milk fat results in slow crystallization dur- hardness and heat resistance during dis- tribution to points-of-sale. ing tempering and produces softer choco- Now that we have defined the attributes of lates. Part of this incompatibility stems from quality, the definition of problems related to the differences in melting characteristics. chocolate application is easier. When we Milk fat is a liquid and cocoa butter is a see any of the above quality criteria out of solid at room temperature (70ºF). synch, or even starting to drift from the We can get a perspective on tempera- norm, we know there’s a problem. ture response of the mixtures of cocoa butter and milk fat from the Jensen cool- KEY FACTORS FOR SUCCESS ing curves (Figure 1). Notice as the milk In producing confections there are four fat increases, the crystal-initiating tem- specific areas where problems occur. The perature decreases and the crystallization first is the selection of the type of choco- rate decreases. late. This is often the primary source of This has important consequences for the difficulties. Here, the level of milk fat in the candy producer, because mixtures that con- chocolate is important. tain both will crystallize at a much slower The second critical issue is chocolate rate. The higher the milk fat content, the application, including storage and handling. longer the tempering time. These mixtures This includes temperature concerns. The also require lower tempering temperatures. third is understanding oil migration, its A slow crystallization rate also means that negative effects and how to avoid or min- the product needs a longer dwell time in imize them.We must understand the inter- the cooling tunnel. action of a chocolate coating with the con- There is another concern regarding the fection’s center during manufacturing, use of milk chocolate in a product which shipping and shelf life. And, finally, there may have nut oil or another type of oil in the are issues associated with the storage of center. The stress on the cocoa butter from finished products. We’ll discuss each in the milk fat, coupled with the interaction some detail. with other fats in the center, will drastically limit the shelf life. The solution? Start with CHOCOLATE SELECTION a lower milk fat milk chocolate. CONSIDERATIONS Current standards allow chocolate suppliers Form to produce milk chocolate with a minimum As I’ve just noted, the type of chocolate is of 10 percent chocolate liquor, 3.39 percent important. But its form is, too. Chocolate milk fat and 12 percent milk solids. is available from the manufacturer in three Higher levels of milk powder and crumb different forms: 138 52nd P.M.C.A. Production Conference, 1998 Milk Chocolate Applications ity. (Chocolate melters require 15 rpm.) The critical Cooling Curves of Cocoa Butter and Butter Fat Once most of the chocolate melts, we factor in using recommend holding the temperature at any chocolate 88ºF or 90ºF, depending on the type of 1 that is already 3 chocolate. Dark chocolates can be used at tempered is 2 90ºF, but milk chocolates, because of the milk fat, should be used at 88ºF. converting the 5 This approach allows for some beta crys- solid chocolate 4 tals to be left intact. This is important into liquid because beta crystals replicate during the without losing 6 cooling process — a coating response that the temper state. is essential in order to achieve a stable ∆t crystalline form in the chocolate. Temperature 1. 100% CB 4. 90% CB 10% BF 2. 100% Softer CB 5. 85% CB 15% BF The temperature of stored bulk liquid 3. 95% CB 5% BF 6. 80% CB 20% BF chocolate is critical, especially for milk Figure 1 chocolate. Its ideal storage temperature is • Liquid, which requires tempering 115º–120ºF. • Tempered and molded 10 lb blocks Exposure to higher temperatures for an • Tempered wafer discs extended period of time will cause the milk Each requires special handling and stor- proteins in chocolate to denature. This age from the time the chocolate is delivered results in grainy texture, off-flavors and by the supplier until it is incorporated into higher viscosity. Thus, monitoring and finished goods. maintaining constant temperatures in the Liquid Chocolate. Liquid chocolate should right range is very important. be stored in vertical or horizontal tanks Obviously, the heat source and the con- with agitation. The agitators should be set sistency of heat distribution is also important. on a timer, so that the chocolate is stirred For example, tanks in hot rooms tend to dis- intermittently — at least 10 to 15 minutes tribute heat more evenly than individually every hour. Keep in mind that when the heated tanks. Jacketed tanks do have their chocolate is being used, the agitator must merits, provided the jackets are designed to be on at all times.The agitation rate for ver- distribute heat evenly and consistently.The tical mixers is 17–18 rpm. Horizontal mix- source of heat, such as hot water in the jack- ers require 13–14 rpm. These are all tank et, must be carefully monitored to guaran- manufacturers’ guidelines. tee that proper amount of heat is transmit- Solid Chocolate. The critical factor in using ted to the stored chocolate at all times. any chocolate that is already tempered is Allowing cold drafts to blow on ther- converting the solid chocolate into liquid mostats or other heat-regulating sensors without losing the temper state. This is can create problems, because this can trig- achieved by warming solid chunks of tem- ger the heating in the hot room or heating pered chocolate or tempered chocolate medium in a jacketed vessel. The result is wafer disks to 90ºF, so that 85–90 percent that more heat than needed reaches a of the cocoa butter melts. Gentle agitation product that is heat sensitive. is needed during melting and cooling to Excess heat applied very briefly may not maintain a uniform temperature profile result in the degradation of the chocolate, and to help to achieve a workable viscos- but excess heat, even by a few degrees, can 52nd P.M.C.A.