Compound coatings have developed in popularity with home chefs and professionals is because they have properties that other coatings such as chocolate do not possess.
Even though chocolate is a benchmark by which all other coatings are judged, other types of coatings are needed when chocolate fails to deliver. Sometimes these coatings are also known as ‘couvertures‘, candy coating, coating chocolate, melting wafers or just non-tempering chocolate so if you are investigating the technology of application then don’t forget to look for these terms too. Pure chocolate coatings for example when used on cakes will shatter when cut which is not the situation when compound coatings are used.
Chocolate Versus Compound Coatings
Chocolate and compound coatings contain three main components (highlighted in other articles on chocolate). They are to recap:
- Sucrose (sugar)
- Cocoa solids – the nonfat part from the cocoa bean. It can be used in various forms but powder is common. Cocoa powder contains not less than 20% cocoa butter otherwise it has to be labelled as fat reduced cocoa powder. The other form is chocolate liquor. The liquor comes from the roasted, hulled and ground form of the fermented and dried cocoa beans.
- Cocoa butter – it was the only accepted fat except for milk fat that was authorised in the majority of countries. In the EU, the directive 2000/36/EC meant that a 5% substitution using other vegetable fats such as palm oil could be used. There are 6 types that are possible. In the USA, no other vegetable fats are allowed which has led many to question the use of other fats in any pure chocolate formulation.
The main difference between chocolate and compound coatings is down to the amount of cocoa solids. By law, chocolate must contain not less than 32% total dry cocoa solids, including not less than 18% cocoa butter and not less than 14% of dry nonfat cocoa solids. Anything else can be called a compound coating.
At its core, compound coating is often a mixture of cocoa powder, vegetable fats, sugars, and often other flavorings or additives. This can be regarded as suspensions of very fine solid particles in a continuous fat phase. The composition of such a mixture is cocoa butter (10-12%) and other vegetable fats (copra, palm, colza, soy, etc.).
The two main benefits are that these types of coating do not require tempering which means they are so much easier to use. Tempering is easy to get wrong so dispensing with this bit of the process is an advantage. Also critically pertinent, they actually cost less on a weight basis! This is because of the use of cheaper ingredients such as hard vegetable fats including palm kernel oil and coconut oil in place of expensive cocoa butter.
To all intents and purposes, these coatings use nearly the same ingredients as chocolate although there are several major exceptions. The fat phase is derived, in part or in full, from any fat, most often vegetable, meeting the requirements of that application. Different sweeteners are used depending on need; sugarfree coatings are produced with maltitol or stevia instead of sugar.
In recent times, the use of compound coating has started to diminish because of the use of hardened palm kernel. To reverse the trend a number of suppliers are now creating coatings with non-hydrogenated vegetable fats. The vegetable fat percentage is of the order of 61-62% w/w. If cocoa powder is added, the level is approximately 12-14%w/w
The compound coating blend is carefully formulated to achieve the desired taste, texture, and melting properties. When melted and applied to the surface of an ice cream stick bar, the compound coating provides a protective layer that seals in freshness, enhances flavour, and adds visual appeal.
Ingredients
Typical formulations for compound coatings are given which are often incorrectly labelled as chocolate. There are times when compound coating is described as ‘no tempering chocolate’. Other instances include ‘tempered chocolate’ and ‘candy melt’. As we mentioned earlier, chocolate needs to contain cocoa butter for it to be a true chocolate
Vegetable Fats
The classic vegetable fat is cocoa butter which is found in chocolate. Other vegetable fats are used and also found in chocolate as well as other coatings. There are three main groups of vegetable fat of interest:
1 – Cocoa butter equivalents
2. – Lauric cocoa butter substitutes – these are those fats containing lauric acid and derived from coconut and palm kernel. These high lauric acid types are ideal for use with ice cream coatings.
3. -Non-lauric cocoa butter replacers.
S.T. Beckett describes the confusion using various terms from ‘alternatives’, replacers, equivalents and substitutes. Cocoa butter alternatives are all vegetable fats that have been used to directly replace or partially replace cocoa butter itself.
The cocoa butter equivalents (CBEs) are vegetable fats that have directly replaced cocoa butter. They have very similar chemical and physical characteristics and are readily interchangeable. There is also considerable research being conducted on enzymatic modification of fats to create the ideal oil for coatings.
The cocoa butter replacers (CBRs) are non-lauric with similar physical but not chemical characteristics to cocoa butter. They are used to replace most of the cocoa butter in coatings according to Beckett.
The cocoa butter substitutes (CBSs) are lauric acid derivatives which behave similarly to the replacers. they could be used to replace almost all the cocoa butter.
The CBEs
The typical CBEs which are permitted in the European Union but not the USA are:-
- Palm (Elaeis guieensis)
- Illipe (Shorea stenoptera)
- Sal (Shorea robusta)
- Shea ( Butyrospermum parkii)
- Kokum (Garcinia indica)
- Mango kernel (Mangifera indica)
Palm oil as fully hydrogenated palm oil (FHPO) is the most common replacement.
Sal fat tends to vary in solidification and needs considerable processing for use as a CBE. Solvent and melt fractionation processing has been examined to understand what the best type of sal fraction might be used. In both types of fractionation a stearin with a yield of 75 to 85% is feasible at 23C (Reddy & Prabhakar, 1990).
Other vegetable fats have been derived from Bambangan.
Tempering
The other major benefit is the removal of the tempering process which compounding permits. Normally, any formula using cocoa butter must be tempered to achieve the characteristic glossy coating. Usually, experts in chocolate work will heat solid chocolate to melt it and then cool it to below its setting point. The chocolate is then warmed a second time to a precise and narrow temperature range for milk chocolate between 31 and 32ºC (88 and 90ºF) and for what is called semi-sweet chocolate, 32 and 33ºC (90 and 91ºF).
The compound coatings on the other hand are handled very differently where they just warmed up to between 3 and 5ºC above the melting point of that particular compound. Small bursts in a microwave are enough to melt the coating. The Barry Callebaut Classic Coating is heated to 49C (120F) in a double-boiler or microwave (30 second intervals). It needs stirring to obtain an even melting. The coating is stirred and mixed until cool to between 31 and 32C (87 – 89F) before used for coating fruit, cakes and biscuits. It only takes 10 minutes to finally use.
The white compound coating is often used because so many different colours can be added to create the desired effect.
If you are coating ice-cream then dip the frozen stick bars in the cool chocolate and refreeze quickly. The frozen ice cream helps to rapidly cool the coating so that it hardens before being refreezed quickly in a blast freezer say.
Flow Behaviour Of Coatings
The flow behaviour of compound compounds has been extensively studied in steady-state systems (Ghorbel et al., 2009). The Casson–Steiner equation was used to fit the compound coating rheograms in the shear rate range 380/s–1,000/s. The behaviour of these coatings is closely related to molten chocolate (Servais et al., 2004) in terms of viscosity and flow properties.
Melting Points
The substitution of cocoa butter in part or fully with other fats suh as palm oil and coconut oil also affects the melting point of the coating. To mimic chocolate melting in the mouth, in other words produce the desired mouthfeel, any replacement must try to satisfy that perception. Studies on chocolate bars where formulations using mixes of cocoa butter, coconut oil and palm oil where the cocoa butter was replaced to different degrees with either alternative fat have been made (Limbardo et al., 2016). The bar made wholly with cocoa butter as the fat melted at 33.5C but with full replacement using palm oil reduced to 31.6C., and with coconut oil to 30.75C. It’s evident that full replacement produces a chocolate substitute which has a significantly lower melting temperature and would thus appear too soft in the mouth. The hardness of chocolate with palm oil were around 88.5 to 139 g on the 1st cycle and 22.75 to 132 g on the 2nd cycle. The hardness of chocolate with coconut oil were around 74.75 to 152.5 g on the 1st cycle and 53.25 to 132 g on the 2nd cycle. The degree of substitution of cocoa butter using other fats was around 60%. Its not clear from the study whether the compound coating containing 40% cocoa butter had a better, similar or worse sensory impact.
Formulations
If you are looking to develop coatings for stick ice-creams then a pure chocolate coating is not really desirable because it is too viscous, will not solidify quickly enough and be too thick. The simplest chocolate style compound coatings will be designed to lower the melting points and reduce viscosity. There are some simple approaches to achieving this.
A dark or milk chocolate compound for ice cream could be:- Vegetable Oil (Palm Kernel, Fully Hydrogenated Palm Oil), Sugar, Whey Powder (MILK), Fat Reduced Cocoa Powder, WHEAT Flour (WHEAT Flour, Calcium Carbonate, Iron, Niacin, Thiamine) Emulsifier: SOYA Lecithin, Flavour.
This formulation contains cocoa powder but is by definition not a chocolate.
A white “chocolate” formulation could be:- sugar, vegetable fat fractionated and totally hydrogenated (palm kernel oil), WHEY powder, whole MILK powder, emulsifier (E492, E322 sunflower lecithin, E472), flavour.
Wilbur offer a cocoa confectionary wafer coating (H449) that contains the following:- COCOA CONFECTIONERY COATING (SUGAR, PALM KERNEL OIL AND HYDROGENATED PALM OIL, NONFAT MILK, COCOA [PROCESSED WITH ALKALI], SOY LECITHIN, ARTIFICAL FLAVOR).
The same brand is available for a Dark Cocoa Confectionary wafer coating: DARK COCOA CONFECTIONERY COATING (SUGAR, PALM KERNEL OIL AND HYDROGENATED PALM OIL, COCOA [PROCESSED WITH ALKALI], NONFAT MILK, MILKFAT, SOY LECITHIN, ARTIFICIAL flavour).
In this instance the cocoa has been dutched i.e. alkali processed).
Emulsifiers such as E492 are not often recognisable to many without expert knowledge. E492 is a fatty acid based on sorbitol and stearic acid. The sources of stearic acid can be both vegetable and animal in origin. That has proved problematic for various religious groups and vegans unless the sources and treatment are clearly specified. E322 too is partially hydrolysed lecithin which in most instances comes from egg yolk, soybean and in the example above from sunflowers. Naming the source helps in making a decision for vegans seeking non-egg yolk ingredients. One emulsifier is E472 which has the extra moniker from a to e that covers various esters of mono- and diglycerides of fatty acids, Another emulsifier often found is polyglycerol polyricinoleate which is derived from the castor oil bean plant.
The compound chocolate is usually available as solid drops such as buttons for ease of handling.
Compound chocolate is usually melted either using a ‘bain marie’ approach where the melting temperature is between 40 and 45ºC or in the microwave for about 30 seconds. The intention of heating is to create a liquid for coating but prevent burning.
Whilst is not mimicking chocolate, Wilbur offer a peanut coating (W796) which contains PEANUT CONFECTIONERY COATING (SUGAR, PALM KERNEL OIL, PARTIALLY DEFATTED PEANUT FLOUR, NONFAT MILK , PEANUT OIL, SALT, SOY LECITHIN).
Barry Callebaut produce PME Candy Buttons Milk Chocolate (Product). The ingredient list is complex: Sugar* Vegetable Oils (Palm Kernels, Hydrogenated Palm Kernel), Cocoa Powder(6-10%), Whole Milk Powder, Whey Powder (Milk), Skimmed Milk Powder, Emulsifier (Soya* Lecithin), Salt, Flavour. * Genetically Modified.
Coatings For Ice-Cream
The simplest coating for an ice-cream can be just chocolate i.e. one containing just cocoa butter with dairy fats but no other vegetable fats. The alternative is a compound coating or couverture. The application could be enrobing, spraying and moulding but increased levels of fat are needed for any coating of ice-cream to be effective.
We know that chocolate can be altered by changing the fat content through different levels of cocoa butter and milk fats. The compound coatings offer a greater variety of options because very different fat levels are available and so are types of fat. As well as cocoa butter and milk fat, we have additional vegetable fats to try out. It is worth noting though that the most expensive coatings and couvertures contain cocoa mass and therefore also cocoa butter.
Chocolate coatings for ice-creams have much higher fat levels – about 40 to 60% than those used for ambient applications which are around 28 to 35%. The reason for this is to obtain more fluid chocolate so that it flows over the whole product evenly. The coating process is extremely brief – a few seconds at most. The higher fat level counters the rapid rate of setting on the frozen surface of the ice cream. The consequence though is that a high fat level means the coating chocolate is much more expensive than the ambient version.
Ice-cream chocolate contains more milk fat so that the coating is less brittle. The formulator does have the option though of varying other vegetable fats to obtain different textures and melting characteristics. If it needs to be a softer coating, sunflower oil and palm oil, especially its soft fractions are used. For the coating to be much harder, a hardened palm oil is required. It is worth noting that coatings of any sort should be processed at a temperature of 35 to 39ºC (95 to 105ºF) if they are lauric acid based.
When cocoa butter is replaced, an alternative which is high in lauric acid is needed. hence the use of coconut and palm kernel oils. Any fat chosen to replace cocoa butter should have no solid fat at 35C. Any solid fat above 3% in the coating tastes waxy. Also, the amount of solid fat must remain constant in the range of 20 to 25C as in this temperature range the fat should remain brittle but hard.
Cargill (Merkens) will suggest for example that a coating for a stick ice cream will deserve the addition of 25% w/w coconut oil (copra) to chocolate to achieve this functional improvement. The colder the coating the better. The chocolate layer created was thin enough to fully solidify as heat was removed from the chocolate layer. The more oil that is added the thinner the viscosity and the lower the melting point and more of the meltdown but there is a balance because the coating becomes applied so thinly that it runs off and edge cracking occurs. The reverse is true if you reduce the oil content.
If you use confectionary coating then it is recommended to use canola (rapeseed) oil or soybean oil. This is down to the type of fat composition of the confectionary coating. Using coconut oil in this instance would not generate the same melting point effect.
A more sophisticated ice-cream enrobing chocolate could contain 40% cocoa butter, 10% cocoa powder, 40% sugar, 5% butter fat, 5% vegetable fat and 3-5% SMP.
One of the primary purposes of compound coatings in ice cream stick bars is flavour enhancement. Whether it’s rich chocolate, creamy vanilla, fruity strawberry, or indulgent caramel, the flavor of the coating can complement and elevate the taste of the ice cream inside. Manufacturers carefully select and blend ingredients to achieve the perfect balance of sweetness, richness, and depth of flavor, ensuring that each bite is a delightful sensory experience.
Texture & Flexibility
Texture and flexibility is another crucial aspect of compound coating applications. When properly formulated and applied, the compound coating adds a satisfying crunch and smooth mouthfeel to the ice cream bar. This textural contrast between the crisp outer layer and creamy interior creates a dynamic eating experience that appeals to consumers of all ages.
The flexibility of a coating is important. There must be resistance to cracking whatever the situation. A soft coconut oil (high in lauric acid) makes a coating very flexible but a hardened coconut oil or palm kernel oil makes it less flexible. What these do though is reduce the tendency for dripping when the ice cream sticks or bars are removed from enrobing or dipping. It appears that formulators attempt to include all three. Adding 5 to 10% non-lauric acid such as sunflower, peanut or soybean adds extra protection from smearing especially during packaging. Non-lauric oils do not produce a soapy flavour when they are hydrolysed. The addition of 0.3% lecithin stops the viscosity rising enough as ice melts producing an aqueous phase in the enrobing vat.
We know that the sensory experience is critical and the cooling of the ice-cream in the mouth means that chocolate should have a lower melting point than ambient chocolate. In other words the melting point is now 21 to 23ºC rather than 32 to 34ºC. Normally, tempering would be applied to ambient chocolate ensuring crystallization to one of the higher polymorphic forms for cocoa butter. That would give better mould release, high quality surface sheen etc. When it is an ice-cream coating, tempering is not needed and in fact is an issue because the flavour and texture turns waxy.
In addition to flavor and texture, compound coatings contribute to the visual appeal of ice cream stick bars. With a myriad of colors, patterns, and decorative elements to choose from, manufacturers can customize the appearance of their products to stand out on store shelves. Vibrant hues, intricate designs, and eye-catching decorations not only attract attention but also evoke a sense of indulgence and fun, making ice cream stick bars irresistible to consumers.
Key Differences Between Coatings and Chocolate
Applications, even with ice-cream produce coatings needing different and specific performance attributes. Ice-cream makers find that there is a contrast and conflict between formulations using particular farts needed for certain types of processing versus those needed for a particular sensory characteristic. Its all about finding the right balance!
The differences between chocolate and ice-cream couvertures/compound coatings are mainly down to the presence of cocoa butter versus coconut oil respectively. We already know that a pure chocolate coating has a narrow formulation range and that is legally confined to palmitic, stearic and oleic acids. The compound coating on the other hand can include numerous fats and oils with a wide range of composition to obtain whatever property is needed.
Chocolate has a high viscosity whilst a couverture is much lower. On that basis, for chocolate viscosity to be optimised or modified even, judicious use of emulsifiers and their concentration are needed. For a compound coating, the viscosity is not only low but has a low pick-up weight and is certainly easier spray than chocolate.
The crystallization rate for chocolate is as fast as a couverture. However, chocolate melts over a wider temperature range from 21 to 23ºC and a higher degree of after cooling is needed. A couverture should melt over a much narrower temperature range which is from 12 down to -3ºC.
The drying times of chocolate are fundamentally different. Chocolate dries in 30 seconds whilst compound coating dries after just 10 seconds.
We know that in terms of melting, chocolate has 6 different crystal forms although that has been modified lately. Its melting range is between 18 and 23ºC when fresh but rises to 23ºC when it has been stored for some time. A compound coating is reduced to two crystal forms termed α and β’. The alpha form rarely survives whilst the beta prime form melts at 23C no matter how long it has been stored.
If you store coated ice-creams you will find that the chocolate truns plastic to brittle whereas a coating compound will always remain brittle irrespective of its storage unless it has been abused.
Beyond sensory appeal, compound coatings also serve practical purposes in the production and preservation of ice cream stick bars. The outer layer acts as a protective barrier, shielding the ice cream from heat, humidity, and other environmental factors that could compromise its quality. This barrier helps prevent melting and freezer burn during transportation, storage, and handling, ensuring that each ice cream stick bar reaches the consumer in perfect condition.
Furthermore, compound coatings allow for customization and innovation in the world of ice cream stick bars. Manufacturers can experiment with different ingredients, flavors, and textures to create unique combinations that cater to diverse consumer preferences. From classic favorites to bold new creations, the possibilities are endless, driving continuous innovation and excitement in the market.
The process of applying compound coatings to ice cream stick bars requires precision and expertise. It typically begins with the selection and preparation of high-quality ingredients, including cocoa powder, vegetable fats, sugars, and flavorings. These ingredients are carefully measured, mixed, and heated to create a smooth, homogeneous mixture.
Once the compound coating is ready, it is applied to the surface of the ice cream stick bars using specialized equipment such as enrobing machines or dipping tanks. The bars are then quickly cooled to allow the coating to solidify, forming a crisp outer layer that encapsulates the creamy ice cream inside.
Throughout the manufacturing process, quality control measures are in place to ensure consistency and adherence to standards. From monitoring ingredient proportions to inspecting finished products for defects, manufacturers strive for excellence at every stage to deliver ice cream stick bars that meet or exceed consumer expectations.
A coating for an ice-cream stick bar suggests that it should be as hard as possible to avoid edge cracking. We’ve found in factory scale studies that the issue is more to do with water migration from the ice-cream into the coating.
Microbiology Considerations
Coatings generally should protect the surfaces of ice creams from contamination by bacteria however there is the possibility of fungal growth on the surface. Few studies have been conducted on bacterial and fungal growth on surfaces. It is most likely that any knowledge is proprietary and held by those businesses who have developed their own types of coatings.
When growth of fungi on coating surfaces occurs it will be because of changes in water activity. Given that most products such as ice creams are stored frozen, the issue of contamination is rare. It is a greater issue with ambient stored products such as chocolate coated candy for example where the water activity can increase on storage. In most situations, food safety studies require growth studies using well established test microorganisms.
Regulations
A compound coatings cannot be called chocolate because it does not meet the legal requirements i.e. Standard of Identity. In other words such coatings contain ingredient(s) not specified in the Standard of Identity. If it is referred to as a chocolate coating it must comply with a chocolate standard. A compound coating cane be described as ‘chocolate flavoured’, ‘chocolate-like’ and even ‘chocolaty’.
Suppliers
Most compound coatings are supplied in tubs of 10 lbs or more. The compound can be reused over again without losing functional performance.
Barry Callebaut: Produce a range of industrial and home cooking coatings. Consider their Classic coatings (29 cents/oz).
Blommer Chocolate – offer specifically coatings but also a range of ice cream coatings. These include ‘Arctic Ice Cream Coating’ which is described as having a moderate cocoa impact. A Lapland Milk which is strongly dairy with a sweet, vanilla and caramel taste.
Cacao Barry :Pate a Glacier Ivorie (approx. 50 cents/oz).
Ghiradelli’s (approx. 49 cents/oz)
Merckens (Cargill) (approx. 24 cents/oz)
Puratos
Wilbur – offer both chocolate and various confectionary coatings
Compound coatings play a vital role in the creation of ice cream stick bars, enhancing flavor, texture, visual appeal, and shelf life. Through careful formulation, application, and innovation, manufacturers are able to produce a wide range of delicious and enticing treats that delight consumers around the world. Whether it’s a classic chocolate-dipped cone or a whimsical rainbow-swirled stick bar, compound coatings add an extra layer of indulgence and excitement to the ice cream experience.
A number of small suppliers are known that supply such compounds.
The Future
Compound coatings will continue to be used where ‘real’ chocolate is not suitable. Over the last decade the use of compounds has dropped off generally by 45% and by 60% with ice-cream stick bars. The replacement coating is chocolate.
One of the main reasons for decline is the continued use of palm oil. A number of suppliers claim to use sustainable sources but the term ‘sustainable’ is possibly being misused given that a number of suppliers are still drawing on palm oil stocks from recently created plantations.
References
Ghorbel, D., Douiri, I., Attia, H., & Trigui, M. (2010). Use of mixture design and flow characteristics to formulate ice cream compound coatings. Journal of Food Process Engineering, 33(5), pp. 919-933 (Article)
Limbardo, R. P., Santoso, H., & Witono, J. R. (2017, May). The effect of coconut oil and palm oil as substituted oils to cocoa butter on chocolate bar texture and melting point. In AIP Conference Proceedings (Vol. 1840, No. 1). AIP Publishing.
Servais, C., Ranc, H. and Roberts, I.D. (2004). Determination of chocolate viscosity. J. Texture Stud. 34, pp. 467–497.
Talbot, G. (2009). Compound coatings. In: Science and Technology of Enrobed and Filled Chocolate, Confectionery and Bakery Products (pp. 80-100). Woodhead Publishing. .
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