Natural casings are traditional casings and have some advantages over artificial casings, such as:
- More natural flavor protection;
- Softness, easy chewing and good digestion;
- It has good absorption and retention of flavor and smoke aroma (from charcoal, wood chips or sawdust);
- It has good elasticity and resists heat and pressure well;
- They provide good twist when separating the sections from the sausages.
The preparation of natural tripe involves cleaning the intestine, scraping and dry salting. The initial cleaning of the casings must be started immediately after evisceration, by removing the attachments and fats adhered to this structure. Next, the intestines are emptied by squeezing them between the fingers, in one direction and along their entire length. Then, the intestines are washed internally and externally with running water and the mucosa (internal side of the intestine) is scraped with a wooden scraper. Once this process is complete, the casings must be washed with vinegar to eliminate the unpleasant smell.
Dry salting is carried out by rubbing coarsely ground salt directly onto the casings that have previously been gathered into bundles. These pieces must be placed on an inclined surface for 24 hours. After this period, the casings are rubbed with refined salt and can then be stored until ready for use.
There are currently processed natural casings on the market. However, when using these casings, care is necessary, such as: removing excess salt with running water and hydrating the casings by immersing them in fresh water for 1 hour (taking care to massage and separate them to avoid possible stains).
When embedding, the casings must be placed in heated water, as this procedure will facilitate the embedding and shaping of the dough into the casing, after filling.