Baking by infrared radiation
Three modes of heat transfer are used in baking biscuits: radiation, conduction and convection. The most important is infrared radiation, which has the following advantages:
Penetrative heat transfer: Infrared radiation penetrates biscuit doughs by approximately 4mm, (depending on wavelength and moisture content). It is the only heat transfer mode to truly bake the product from the centre. This is the key advantage of baking by infrared radiation
Biscuit structure: because radiation penetrates the dough pieces, it is essential to achieving good structure with optimum volume and texture and is always the main mode of heat transfer in the first part of the baking process
Even moisture content: radiant baking ensures a low moisture gradient from centre to the outer surface of the biscuit. It is the best heat transfer mode to avoid “checking” (cracks appearing in the biscuit after baking)
Efficiency: heating of the surrounding air in the baking chamber is not necessary, which lowers energy consumption
Colouring: radiation enables highlighted colour contrasts for crackers and rotary moulded products, whereas convection gives an overall, bland, even colour
Versatile: infrared baking is suitable for all types of biscuit