How sausage casings are made
Natural sausage casing is the inner lining of an animal's small intestine, sold by the hank.
- stations
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- things upstream
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- raw sources
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- steps from the ground
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The short version
Natural casings are the submucosa of a meat animal's small intestine, mostly collagen. Cleaning plants strip off the fat and contents, crush the gut between rollers and slime away every other layer. The tube that remains is inflated to grade its diameter, packed in salt and sold in hanks. Artificial casings are extruded from collagen or made from cellulose.
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Pull the runners
At the slaughter plant, uncleaned intestines called runners are pulled from the animal. A pig's small intestine averages 15 to 20 meters long. In Western European and Chinese cuisine, most casings come from pigs.
Goes in -
Strip fat and contents
Workers or machines remove the fat and mesentery, a step called running. The contents are then pushed out, which is called stripping.
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Crush between rollers
The intestine passes through a mucous crusher, whose rollers break up its inner lining so it will come away.
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Slime off the layers
A second set of rollers scrapes away the mucosa, both muscle layers and the outer serosa. Pig rounds keep only the strong, collagen-rich submucosa. Older plants got the same result by fermenting the guts and sliming by hand.
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Inflate and grade
Air or water blows up each length so its diameter can be measured. Pig grades run from narrow, at 28 mm and under, to extra wide, at 42 mm and over.
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Pack in salt
Graded casings are salted heavily, about 40 percent salt, and stored that way until used. Sausage makers soak them to desalt them first.
40% salt
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Bundle into hanks
Pig rounds sell in hanks of 100 yards, usually 15 to 20 pieces of roughly equal length.
91.4 m per hank
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Or extrude collagen tubes
Artificial casings are made from collagen, often from cattle skin, shaped by continuous extrusion. Cellulose and plastic casings also exist, and they deliver a uniform diameter.
Goes in
Worth repeating
- Artificial casings were introduced in the early 20th century.
- Sheep, goat, cattle and sometimes horse intestines are also used where pork is not.
Back to the ground
Follow every input upstream and sausage casing starts as these 4 raw sources.
Everything it is made of See it on the map
Open the whole family tree
Where it goes next
Sausage casing feeds 3 lines directly and reaches 4 things in total.
Further down the line
Keep walking
Sources
Cite this page: "How sausage casings are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/sausage-casing