Preparation of raw materials (Gelatin)
Two principal processes are employed in the manufacture of gelatine:
Acid process - for type A gelatine:
The raw material (primarily pigskin) is first subjected to a 3-day digestion process. Here, the material is treated with acid and immediately afterwards the gelatine extraction process can be commenced.
Alkaline process - for type B gelatine:
This process extends over a period of several weeks and gently converts the collagen structure. Only ossein or split can be used. The collagen produced in this way is soluble in warm water.
Warm water is then added to the pre-treated material and a multi-stage extraction process commences. The first gelatine fractions obtained, at low temperature, have the highest gellation status; an approximately 5% solution is obtained. The remaining material is then extracted using fresh, warmer water. This process is repeated until the last traces of gelatine are extracted using boiling water. As the pre-treatment carried out is extremely thorough, very little residue remains after extraction.