Once the mixture is formed, it is pushed from the churning tank to its packaging line.

In the process, the fat, still warm and liquid, will be abruptly cooled by alternately passing through cold tubes, working tubes and resting tubes to gradually switch from a liquid to a solid state.

To outline the principle, the cold tubes could be likened to a giant ice cream maker. They consist of several concentric tubes. A refrigerant flows through the outer ring that is cooled between 0 and -25 ° C. The fat mixture flows through the central tube. The cold exchange between the annulus and the fat in the centre will cool the product and thus trigger the crystallisation process. The crystals, formed in contact with the cold intermediate ring, are scraped off by means of knives secured to a rotary central axis. The refrigerant and fats obviously never come into direct contact with each other.

The working tubes in turn are crossed by an “agitator” shaft whose job is to break a part of the crystal lattice being formed. Placed alternately with the cold tubes, working tubes are used to give time to the product on the line, to achieve crystallisation. They also can play on the size of the crystals that will give body or flexibility to the product.

Finally, the product simply passes through the resting tubes at the end of production. These pipes will ensure the completion of the product crystallisation process before it is packaged.

The expertise of the margarine maker is necessary to apply the most appropriate production parameters to obtain the optimal crystallisation of the selected recipe. Choosing the order of passage through the various tubes, a quick or slow passage through the system, applying a very intense or more moderate cold in the cold tubes, increasing or reducing the processing time of the material, etc., are the many elements that need to be taken into consideration by the margarine maker.

Indeed, this crystallisation will greatly influence the textural properties and plasticity of the fat used by the customer. Because a crunchy cookie or a fluffy brownie will require fats with completely different textural properties.