Natural rennet. There are many ways to make natural rennet, starting from completely primitive, and ending with the improved, at the same time creating a cheese culture of bacteria. They all rely on this common treatment, that the finely chopped mites are soaked for some time in water or whey, to which fixatives are sometimes added, e.g. table salt. After some time, the mortar is removed, to remove soaked stomach particles. Carpathian highlanders soak their stomachs along with the unpressed, dried content.
The natural rennet prepared as described above has serious shortcomings. From a bacteriological point of view, it is very uncertain, and moreover, it is unstable, if it is not treated with chemicals. The power of natural rennet varies, which makes it inconvenient to use. Finally, the lift is expensive, since the extraction rate of the rennet enzyme is usually insufficient. So for the reasons mentioned, except in special cases, priority is given to artificial rennet. Rennet is always used to make Emmental cheeses, natural, properly prepared, which will be discussed next.
Artificial rennet. Each artificial rennet is first made from a liquid extract obtained by macerating chopped abomas in salt solution.. When we remove solid parts from it by straining or filtering and fix it with chemicals, we will get a liquid rennet extract. With further treatments, rennet ferment can be precipitated from the extract in the form of a gray sediment, which, when dried in a vacuum, forms a powder rennet.