Chocolate Fat Bloom Fat bloom is inevitable, but once you understand the fundamentals you can prevent it from occurring prior to the end of shelf life. Melissa Tisoncik Blommer Chocolate Company at bloom is a common occurrence tags are the building blocks of a strong foun- Fwhen working with chocolate products. dation. A tag molecule is composed of a It is a physical defect that appears during glycerol backbone with three fatty acid chains storage of chocolate and is characterized as linked by ester bonds. This molecule is most a whitish layer on the outer surface (Fig- commonly illustrated in a chair-like or tuning- ure 1). Chocolate with fat bloom is not only fork formation. These tags can crystallize in visually unappealing, but also impacts the six different polymorph formations (Forms I- flavor and textural qualities, which are im- VI), which have specific melting points. Poly- portant determinants of consumer prefer- morph Form V is the ideal form to achieve Melissa Tisoncik is ence. The phenomenon is not fully under- when working with chocolate. When cocoa the research and devel- butter is in this form, chocolate achieves stood, but research suggests there are many opment manager – factors which may contribute to fat bloom many favorable attributes such as a smooth, product development formation such as poor tempering, mixture even melting, clean snap and nice gloss. This at Blommer Chocolate of incompatible fats, disrupted cooling can be accomplished by tempering. in the company’s methods, temperature fluctuations, storage Chicago R&D team. Previously, she worked conditions and abrasion or finger marking. Chocolate Fat Bloom at the USDA labs. Fat bloom impacts all of us: manufactur- ers, suppliers and customers alike. It is im- portant to understand when and why it is occurring to hone in on the problem and implement a corrective action. Overall, fat bloom is inevitable, but once you under- Figure 1 stand the fundamentals you can prevent it from occurring prior to the end of shelf life. Molecular Chocolate Matrix CHOCOLATE STRUCTURE Chocolate has a complex flavor profile and compositional matrix consisting of sugar, co- coa particles and emulsifiers dispersed in a continuous phase of cocoa butter (Figure 2). Cocoa butter is a polymorphic fat composed of three main triglycerides (tags). These Figure 2 ➤ The Manufacturing Confectioner • April 2013 65 Chocolate Fat Bloom Dirty moulds can Envision that all the tag molecules are mould that acts as seed or site of crystal initiate fat bloom individual and mobile when cocoa butter nucleation for subsequent deposited due to a residue is in its liquid state at 120°F. As the mass chocolate. This newly deposited chocolate chocolate layer begins to cool, crystals begin to form and will form surface bloom. Proper cleaning being left on the eventually a crystalline lattice is created of moulds is essential. (Figure 3). If the tag molecules create a mould that acts Temper (during application) Figure 5 is a disorderly nonuniform stacking, fat bloom as seed or site of great representation of improper temper formation can occur in the finished choco- crystal nucleation that caused fat bloom. Can you see the late product. This can be initiated by tem- for subsequent layers formed? This indicates that in each perature fluctuations, improper applica- layer the chocolate was already crystaliz- deposited tion techniques, improper handling or ing as it was deposited into the mould. It is chocolate. processing failures when working with important to note that the cross-sectional chocolate. view of a chocolate product can give in- sight to your bloom investigation as well. INVESTIGATING FAT BLOOM Cooling (postapplication) Figure 6 reveals It is important to ask the following ques- a common case of fat bloom found right tions when investigating cause of bloom: after the cooling tunnel or on retail • How does fat bloom affect our product? • Where is it seen on the production line? • When do we see it occurring? Cocoa Butter Solidifying Schematic • What is the cause? • What challenges do we experience while working with chocolate prior to pro- duction, during production or postpro- duction? Fat bloom can appear in many different ways, but the following case studies will give you general guidelines to help deter- Figure 3 mine the root cause and answer the ques- tions posed above. Extreme Temperature Fluctuations TYPES AND CAUSES OF FAT BLOOM Extreme temperature fluctuations (postap- plication) The image in Figure 4 shows that environmental handling conditions were not ideal. In this case study, bloom has im- pacted the structural integrity of the choco- Figure 4 late product and completely deformed it. Poor Tempering This is caused during transportation or dis- tribution, e.g., the shipping truck sitting at temperatures 5° to 10° above the melting point of chocolate. Dirty moulds (during application) Dirty moulds can initiate fat bloom due to a residue chocolate layer being left on the Figure 5 ➤ 66 April 2013 • The Manufacturing Confectioner Chocolate Fat Bloom shelves. This is due to improper cooling. You must look at the cooling capacity and It helps to create a Chocolate is more susceptible to this type check the temper prior to moulding. thicker chocolate of bloom if you have poor temper as well. Temper/depositing (during application) shell around the This is a unique case of fat bloom (Fig- center to prevent Insufficient Cooling ure 7) which needs to be investigated fur- invasive migration ther. At first glance, it appears to look like and bloom on the a milk/dark drops mixture; however, tak- surface from ing a closer look, you can see the streaking occurring too in the individual drops. You can perform a rapidly. quick visual and sensory analysis to test for fat bloom. Looking at the cross- section (Figure 8), one can see that the dark drop Figure 6 on the bottom is very uniform whereas the light drop on the top is very speckled Poor Tempering/Depositing Problems and crumbly looking. The taste is also very dry, void of flavor and crumbly in the mouth. When you melt down the drops, the color slide indicates the same color chocolate. These tests helped draw the conclusion that this was not a mixture of milk and dark drops, but it was fat bloom. Formulation (prior to application) If you Figure 7 see extensive bloom (Figure 9) and you Visual/Sensory Analysis of Bloom have ruled out all environmental factors Formulation Issue and production as a factor that may cause bloom, you need to look at the formula. There may be an inherit formulation issue that caused the chocolate to bloom at a quicker rate when exposed to high heat temperatures. This type of bloom forms within 2 to 4 weeks after depositing and is caused by a mixture of incompatible fats. Figure 9 Interaction with inclusions (postapplica- tion) Figure 10 reveals fat bloom forma- Interaction with Inclusions tion due to cocoa butter interacting with incompatible oils, such as peanut oil. These liquid oils will migrate into the chocolate shell by dissolving cocoa butter liquid frac- Flavor/texture test tions, then migrate to the surface and form bloom. It helps to create a thicker choco- late shell around the center to prevent in- vasive migration and bloom on the surface from occurring too rapidly. Wet slide test Figure 10 Fat bloom can develop at many differ- Figure 8 ➤ The Manufacturing Confectioner • April 2013 67 Chocolate Fat Bloom Combining cocoa ent stages. The timeline in Figure 11 is an be added to a lauric oil-based or a cocoa butter and a lauric excellent gauge to help identify the root butter-based product respectively. Other fat such as palm oil cause of bloom based on when it appears products used in final formulations with or coconut oil will throughout production. Once identified, chocolate are nut oils (enrobed nuts), co- promote blooming a corrective action can be taken, but there conut oil (meltaways) and soybean oil (liq- are also various preventive methods you uid chips). Creating a barrier between the and result in a soft can utilize to inhibit fat bloom formation. two incompatible fats is another key idea texture due to their to consider. A great example of strategic eutectic effect. PREVENTATIVE METHODS layering is seen in candy bar products, Tempering where sugar caramels create a barrier be- tween the nuts and the enrobed chocolate It is essential to understand that the subtle- layer. Also, a common ingredient added to ties in this time/temperature process can inhibit bloom (within the standard of iden- impact your product further down the line. tity for chocolate) is milk fat. The medium If chocolate is not properly tempered, the chain fatty acids in milk fat can interact incorrect crystalline structure is formed, with cocoa butter structure to prevent mi- which in turn can lead to bloom. A great gration and bloom. test to check temper is using the Tricor tem- permeter instrument. It is a quick method Proper Storage for operators to use on the line. The easy This is something we can try to control readouts are translated into a number in- while transporting chocolate. Proper stor- dicating good, great or need to retemper. age, whether it be postproduction, ware- Knowledgeable Formulation house, distribution, customer end or retail shelving, is essential to prevent bloom from During formulation it is important to think occurring before the shelf life expires. At about the end application and how the this point, chocolate is most susceptible to chocolate will function. You must consider temperature fluctuations. The best condi- the other fats in the final formulation and tions for chocolate storage are a controlled weigh the risk of incompatibility. Com- environment at room temperature and 40 bining cocoa butter and a lauric fat such as to 60 percent relative humidity.