Sheep casings

Sheep Casings

Some times the term sheep runners is also used.

You are talking about the small intestines which could provide many feet of sausage casing.

Hand pulled casings do not have threads of connective tissue on the outside (Called whiskers). They are delicate and usually have shorter strands than knife cut. They may have more holes or weak spots.

Knife cut casings have the small threads of connective tissue (Whiskers). Their strands are usually longer and have fewer holes. The threads of connective tissue on knife cut casings will melt off on smoked or cooked sausage.

Steps for the conversion of the digestive tract into sausage casing.<Rwf>Source: Ockerman, 1996. Chemistry of Meat Tissue. The Ohio State University, Columbus, OH, USA.</Ref>

1. Removing the intestine from the animal.
2. Running - removal of loose mesentery fat.
3. First stripping - squeezing to force out intestinal contents.
4. Washed and cooled (50oF water).
5. Mechanical stripper or hand stripping.
6. Brushes used to remove fat.
7. Slimming - removal of tissue layers - revolving drums and warm (115F) water or hand slimming.
8. Strippers or hand removal of appropriate tissue layers.
9. Stored overnight in ice and 15 to 20% saturated salt solution.
10. Graded - species, size, quality.
11. Cured - rubbing with salt; allow to set for 1 week.
12. Removal from cure, shaken free of excess salt, rubbed with fine salt, and packed (40% salt).
13. Flushed prior to use.

Removal of the Viscera

The first step in casing preparation (Table 3) is removing the viscera and separating it from the internal organs. This is primarily a hand and/or knife operation. The viscera is placed on a table and separated from the mesentery fat. Again, this is a hand operation which can be facilitated by using an air operated knife. The puller usually will start at the stomach and pull the casing away from the ruffle fat.

The next step in casing manufacturing is to run the casing through a manure stripper to squeeze out the liquid and manure using large rollers similar to a laundry ringer. These rollers are usually rubber and sometimes are wrapped with burlap. This operation also can be done by hand by pulling the casing through the fingers. In either case, a great quantity of potable water is needed to wash the casings and to keep the operation clean. The casing should be soaked for approximately 30 minutes in 100 to 108F (38 to 42C) water. In some areas of the world, casings now go through a fermentation cycle, but in many areas, processing casings by fermentation is no longer legal (e.g., USA). If fermentation is to be conducted, the casings usually are soaked overnight in 72oF (22oC) water or until the mucosa and muscular coatings are loosened. Excessive fermentation will soften the casings. If fermentation is used, the casings usually are stripped after fermentation, soaked, restripped, and often restripped again. Next, they are run through a cleaning machine (which is often a drum with a revolving scraper blade).

If the casing is not fermented, the next step is to run it through a crushing machine and soaking tank. The purpose of this is to break the intermucosal membrane and separate it from the casing. This machine also has two adjustable rollers with eccentric bearings. Again, a great quantity of 108oF (42oC) water is used in this operation. Crushing also can be accomplished by a hand operation wherein the casing is scrapped with a dull-bladed knife or an oyster shell.

Next, the casing goes through a mucosa stripper, which looks essentially like the manure stripper. Again, 108oF (42oC) water is used to keep the operation sanitary. If labor is very economical, this operation also can be accomplished by hand scraping.

Next, the casing goes through a finishing machine to remove any string-like material and remaining mucosa. Rollers again are used in this operation. Finishing also can be accomplished by hand if a great deal of attention is paid to detail. In either system, large quantities of 108oF (42oC) potable water are essential to keep the operation clean. After finishing, the casings are soaked again in 50 to 60oF (10 to 16oC) water and/or a salt brine tank to remove excess blood. This tank normally has continuous flowing water to remove the stained liquid. If continuous running water is used, salt normally is not used at this stage. The soaking time usually ranges from 30 minutes to overnight.

After the soaking operation, casings usually are salted either by hand or again by machine. The salting and shaking of the casing usually are continued until the casings absorb 40% salt, at which point they are packed into a container. If the casings are packed in a slush container, the container will hold 10 to 15% salt water brine. The advantage of using a dry pack is that the casings become less tangled. Also, the casings will be darker in color.

Items such as hog bung, hog stomach, blind end or cecum, bladder, beef bung, and weasand usually are handled by hand, trimmed of excess material, and salted again.

If attention is paid to detail, large quantities of cool water are used to keep the casings clean, labor is inexpensive, and strict sanitation is maintained, then suitable casings can be produced by hand operation and will make very desirable casings for the sausage industry. However, a breakdown in any one of these processes will result in an unsanitary product that has little use in modern sausage processing.

Casings names and locations, as well as sausage products for which they are utilized and yield per animal can be found in Table 4. How to use sausage casings in the meat packing industry can be located in Table 5.

If all steps of the process are performed satisfactorily, a very gourmet sausage product can be produced by utilizing value added and upgraded animal casings which, in their native state, have almost no value but can be transformed to a very desirable container for high quality sausage products.

Store in the cooler at 40º (4.44ºC) or less in brine or well salted. NEVER freeze casings. If storing casings in brine for extended periods of time refresh casings periodically by changing the brine. Keep containers sealed in the cooler.