The ingredients are selected and blended, with proportions varying depending on the recipe and the type of chocolate to be made; milk, white, dark, gianduja.
Large cylindrical refining machines crush and cut the chocolate mix into particles no larger than 18 micron.
Conching can take hours, and is carried out for a number of reasons:
• to create a perfect blend of the various components
• to reduce the acidic, astringent aromas
• to extract the residual humidity, which at the end of the process should not exceed 0.5-0.8%.
At this stage, a small amount of soya lecithin (0.3%) is generally added as an emulsifier to make the chocolate smoother, together with a tiny amount of vanilla to enhance the flavour.
Before being moulded, the chocolate paste must be subjected to a heat treatment known as tempering (8), during which the chocolate is first cooled to 26°/28° and then heated back up to 29°/32°. This is essential for the cocoa butter to solidify in a stable crystalline state in order for it to maintain the required shape once turned out of the moulds, a glossy appearance and a clean break without crumbling, as well as to ensure it keeps well.
Once tempered, the chocolate is poured into moulds for shaping into bars, pralines, eggs, etc. It is then solidified in large cooling tunnels, at the end of which it can easily be removed from the moulds.
The solid chocolate may now be wrapped and packaged in imaginative, eye-catching ways.