How Quantex pumps manage the high viscosity of chocolate solutions
Product viscosity is a very important consideration for any manufacturer or flow-control engineer who manages the dispense of thick , highly viscous liquids , but especially for those working with chocolate or confectionery-related products due to the unique and variable viscosity of chocolate .
The pressure and flow rate needed to propel the produce out of its primary container and into its intended location will differ depending on the viscosity of the liquid . In the case of melted chocolate , however , the final viscosity can vary greatly depending on the differences in production , composites , temperature and other factors . Examples of different chocolate-related food and beverage items and their approximate viscosities are noted in the below table : ( Note pure water is 1.0cP ).
Chocolate starts its life from the Cacao tree . This plant will produce the cocoa beans / seeds which are then roasted and ground into a paste . The paste is then mixed with ingredients that may include milk , sugar , emulsifiers and other flavourings depending on what type of chocolate is being manufactured . The final viscosity of the chocolate depends on how the chocolate is treated , its additional ingredients and how it gets manufactured .
Multiple factors can alter the viscosity of chocolate products , these include :
Fat content – the higher the fat content , the more viscous a product tends to be e . g it ’ s considered that
12 FDPP - www . fdpp . co . uk
Product ( at room temperature unless specified ) Viscosity ( centipoise cP ) Caramel Chocolate
‘ the higher the percentage of cocoa butter , the more viscous the chocolate will be ’. If the first ingredient listed on a product label is cocoa butter , then the chocolate is considered more viscous as it indicates that it has a higher quantity of cocoa butter than its other ingredients . This would indicate that dark chocolate ( which has a higher level of cocoa butter ) is more viscous than milk chocolate or white chocolate .
Added ingredients ( flavours ) – In order to make chocolate , the cocoa nibs and cocoa butter need to be mixed with other ingredients that hold their own viscosity levels , therefore altering the product ’ s final viscosity level .
Emulsifiers – products with more emulsifiers tend to be less viscous as the emulsifier will aid the smoothening of chocolate .
Degree of temper – this is the temperature needed at various stages to keep the liquid chocolate melted and at it ’ s best condition . If chocolate is not tempered properly , the cocoa butter crystallisation is uneven
400 @ 140 ° F
Fudge ( hot ) 36,000 Toffee 87,000 Milk Corn Oil 30 Corn Syrup 41 Be Glucose Honey
17,000 @ 120 ° F
1.2 @ 60 ° F
15,000 @ 60 ° F 10,000 @ 100 ° F 1,500 @ 100 ° F
and uncontrolled , resulting in an unattractive dull looking chocolate with white streaks throughout it . If allowed to cool enough , it would harden becoming more viscous during manufacture .
Temperature – a colder temperature significantly increases the viscosity of a product making it more solid and less smooth / runny .
Conching time – this entails the continuous movement and displacement of the product over a prolonged period . The longer the conching process , the more viscous the chocolate will be .
How conching affects the viscosity of chocolate
When we talk about the conching process of chocolate , we ’ re referencing the continuous grinding , mixing , and kneading of the chocolate solution over time . During this process , the chocolate will undergo mechanical shear forces , be heated and be distributed to multiple destinations . It ’ s in this process that the tiny particles of solids ( often cocoa , sugar , and milk ) acquire a more uniform and consistent shape allowing them to be evenly coated with cocoa butter . This process will determine the viscosity of chocolate , how it flows , its textural properties and determines how the finished product will melt smoothly in the mouth .