Anyone familiar with sausages of any type is also familiar with casings. Whether it’s a kielbasa or the classic hot dog, casings are a natural part of the process.

For centuries, the only option for a sausage casing was natural. Namely, it was the intestinal lining of the animals that had provided the meat for the sausage. Today, there is choice. And the choice between synthetic and natural is a matter of taste.

Natural casings are often used with traditional products, such as the hot dog. One company, Vienna Beef Co. of Chicago, uses natural casings for hot dogs and other products being sold in its home city.

“In Chicago, where the Chicago-style hot dog is an icon, the natural casing for some is essential for authenticity — offering an appealing curve to the hot dog and a ‘snap’ when you bite into it,” says Jane Lustig, a spokeswoman for the company.

Lustig goes on to say that natural casing sausages are often handmade and cost more than synthetic. The skinless version of the hot dog, made with the synthetic casings, have the same flavor profile at a lower cost. Consumers can find both natural-casing and skinless products in restaurants and supermarkets currently carry a skinless product.

Johnsonville Sausage Co. of Sheboygan Falls, Wis. is another company with a faithful following of its sausage products. Like Vienna Beef, they use a variety of casings. Which type used depends on factors such as machinability, cost and performance.

Integral

While the casing may be the last ingredient to go onto the sausage, it is a major part of the final product.

“The casing is a raw material that has many purposes,” says Kevin Ladwig, a vice president at Johnsonville and the director of science and procurement. “Beyond the obvious of shaping the sausage or conveying it through a process, the casing has a lot to do with the finished product attributes. So the decision on what type to use needs to be a blend of process and product with a keen eye toward what consumers want in the eating experience.”

There are rules for casings of course. The Food Safety and Inspection Service (FSIS) says if the casing comes from a different species, then the label must state it. For example, if a turkey hot dog has a pork casing, the label must list the pork casing on the ingredients list. If the casing is artificially colored, the label must indicate that too. Many synthetic casings, especially those that are inedible and meant to be taken off after cooking, are often used for flavor. Anything that changes the nature of the meat inside must be listed. The inedible casings are often made from cellulose or plastic.

Lustig says that Vienna Beef produces hot dogs, polish sausage and specialty sausages with both natural casings and synthetic casings. Slicing sausages such as bologna and salami are produced with synthetic cellophane casings, and beef sticks have synthetic, edible collagen casings. Customer choice, especially for the company’s hot dogs, often figure into the decision on which kind to use.

“Natural casings call for a more selective process,” says Lustig. “The sizes of natural casing products we make at Vienna Beef call for a casing from a sheep or pig, and for quality and safety purposes we purchase from select regions.”

The casings used aren’t proprietary for many companies that use them. However, how they’re used, is.

“By making subtle changes in casing handling, preparation and processing, finished product attributes can be customized to fit a market need,” says Ladwig. “Significant technology and trade secrets reside in this area.