Dusting of chocolate truffles with a cocoa powder
A chocolate “truffle” is a soft or hard chocolate core on which a powder – cocoa or else – is dusted to enhance the appeal and the taste.
The core product if made of chocolate results from a moulding or a depositing process.
Depending of the forming process, the surface will be respectively hard and dry or soft and sticky (from the cocoa fat content). The same applies for other masses such as fruit paste, marzipan.
If the core product results from a moulding process, its surface is generally “dry” and not sticky.
It requires the preliminary application of a sticking medium to trap the powder :
- Fluid chocolate – see the Chocolate enrobing process
- An hydrocolloid solution is an alternative.
If the core product results from an extrusion process and its composition is adequate, the surface is “sticky” and ready to catch a powder.
The powder used for dusting are :
- Cocoa powder, the obvious choice
- Icing sugar
- Fruit powders
- Any other suitable fine powder such as ground spices (cinnamon, red pepper …)
How does it work?
The wet or wetted truffles must be exposed to the cocoa powder and be tumbled in it.
Subsequently they must be separated from the bed of powder. The adhesion time is relatively short. The separation process should remove the powder not adhering to the sticking medium while not adhering to it.
The excess powder is sifted to remove chocolate particles and recycled. Fesh powder is brought in to compensate. The process runs as follows
Enrobing with a chcolate layer or else
Separating of the powder, sifting and continuous recycling
Cooling to set the chocolate layer
Different systems are used to form a bed of powder, tumble the truffles in it and separate them.
- A vibrating tray
- A mesh conveyor system as used to coat nuggets with breadcrumbs
- A rotating tumbler
- A rotating screw or twin-crew system
The selecion of he system must take into account the tumbling motion but how the sifting and recycling operations are carried out, as they are the most difficult to achieve without losses and pollution.
Tumbling in continuous screw system with a sieving and recycling zone is a solution. Twin-screw dusting sytem – Sugar InProcess
How do you measure your success?
Key quality features
The experience should be as close as with an artisanal cocoa dusted truffle
Even distribution of the cocoa powder
Deformation of the product up to a certain level may de desire
The powder shoud hold and not be absorbed by the wet surface of the truffle
Key quality parameters
The producer should master a set of parameters as much as possible
It can be cocoa powder of specific fat content, or else such as dried fruit powder
The motion applied to the product depends on principle (conveyor, screw, vibrating tray), design and operation (speed)
The base being chocolate, a careful control of the temperature during and beyond the process is critical