What Are Collagen Casings Made Of? Ingredients & Process
There’s nothing quite like the crisp, juicy snap of a collagen-cased sausage, hot dog, or dried meat snack. The slightly toothsome bite of collagen-based casings locks in moisture, produces an even cook, and delivers a unique, enjoyable mouthfeel.
As delicious and beloved as collagen casings are, they’re a bit of a mystery to many grillmasters, sausage makers, and home chefs. You may even wonder to yourself: What are collagen casings made of and how are they produced?
Luckily, collagen isn’t all that mysterious: It's an animal-based protein found in countless foods. From ingredients to different preparation methods, let’s walk the journey your collagen casings take from processing facility to production line.
Introduction to Collagen Casings
Collagen casings are, unsurprisingly, produced from collagen. Collagen is the most common protein in the human body, and it’s likewise found in a variety of other animals, such as:
- Cows
- Pigs
- Fish
Collagen is generally found in an animal’s connective tissue and bones—which is why it makes for such revered casings.
Collagen casings are pliable and easy to work with. They don’t require pre-soaking or untangling from a messy web of other casings. They're also safe to eat and easily digestible—though there are some inedible versions.
Despite being derived from animal tissues, collagen casings are technically synthetic. This allows sausage makers to produce them to the exact size they need, minimizing waste and making for easy portion control.
Ingredients in Collagen Casings
As noted, the primary ingredient in collagen casings is collagen. But how does collagen get from animals into your casing? And are there any other ingredients that get added along the way?
Primary Source: Collagen from Animal Hides
In theory, it’s possible to extract collagen from any animal on the planet. In practice, however, collagen for casings is primarily produced from two types of animals:
- Cows
- Pigs
Collagen is generally made from the lesser-eaten parts of animals like skin and connective tissue. These bits are loaded with the natural protein that needs to be extracted to be useful.
To get collagen from these pieces for use in casings and other food products, producers:
- Grind the bits to usable sizes and wash them thoroughly.
- Treat them with an alkaline mixture that removes impurities and non-collagenous materials.
- Use an acidic solution to solubilize the collagen—or break it down into a liquid or solvent form.
- Dialyze the solution (remove its impurities) then freeze-dry it for use.
At this point, the collagen can head out for cosmetic, commercial, or culinary use—including for sausage casings and similar foods.
Additives and Processing Agents
Collagen casings often contain no additives aside from a little cellulose for structure—plus the meats, spices, and other ingredients you stuff into your sausages. Certain producers may want a specific look or longer shelf-life for their casings, however, so they’ll add:
- Food-safe colorings – Depending on their final use, casing manufacturers may add mahogany or red coloring to achieve a bright, tempting exterior.
- Preservatives – Sorbic acid, sulfur dioxide, sodium carboxymethylcellulose, and other common food-safe preservatives are often added to casings to help them last longer.
Step-by-Step Production Process
Now you know where collagen comes from, but how is it made into casings? There’s actually an involved process that transforms pure, refined collagen into the right shape and form for filling with delicious sausage stuffings.
Collagen Extraction and Purification
As noted, collagen extraction is a precise chemical process in which animal hides and connective tissues undergo multiple treatments in both alkaline and acidic solutions. Afterward, manufacturers are left with pure, solubilized collagen that can be used in beauty products, commercial goods, and foodstuffs.
Collagen purity is of the utmost importance as the end users eat the final products or apply them to their skin. To test for purity, manufacturers run a variety of tests, including checks for:
- pH balance
- Conductivity
- Residual salts
- Ash
- Arsenic
- Heavy metals
- Other non-collagenous components
After producers have ensured their collagen’s purity through rigorous testing, it’s ready to ship out for future uses. In the case of casings, this means they’re ready to be formed and dried.
Forming and Drying Process
Casing manufacturers will often mix different kinds of collagen—such as those derived from both cow and pig skin—into their final mixture. On top of having their own unique blend of collagen types, different producers will also vary on their:
- Moisture content
- Drying time
- Overall production process
While the exact procedure can change from producer to producer, the general process for forming casings involves:
- Mixing the collagen into a thick, workable gel.
- Feeding the gel into an extruding machine.
- Extruding the casings to the manufacturer’s desired width and thickness.
- Drying the casings until they reach the intended moisture level.
Once the casing is dry, it’s ready to be sent on to its next stop: cutting and packaging.
Cutting and Packaging
After casings are formed and dried, they're ready to be cut into their final shape. Manufacturers produce casings from frank to footlong size (and beyond) depending on their intended uses.
After they’re cut, the casings are wrapped up and often vacuum-packed. They’re then loaded into boxes and shipped to sausage makers to become the delicious, meaty treats we know and love.
Different Types of Collagen Casings
Most manufacturers use a proprietary collagen blend in their casings but, beyond this, there are other ways they make their final products unique.
Three popular types of collagen casings sausage makers use in their recipes are:
- Fresh
- Smoked
- Dried
Choosing the right casing can make a world of difference in your sausages—so know when to use each for the best results.
Fresh Collagen Casings
Fresh collagen casings can be used in a variety of applications. Most notably, they add a tempting tint to the outside of sausage skins, enhancing their visual appeal. This signature, translucent shine beckons to shoppers in supermarkets and diners in restaurants.
In general, fresh collagen casings are best used for fresh sausages. They have a softer, more delicate texture that melds well with the fatty, juicy burst of ground meat. Whether you’re making bratwursts, boerewors, beef franks, or any other style of fresh sausage, use fresh collagen casings to achieve the smoothest mouthfeel.
Smoked Collagen Casings
Smoked collagen casings are simply fresh casings that have been in a smoker or other smoke-infusing device long enough to impart a noticeable, fiery flavor. They’re perfect for hot dogs, which often pick up a smokier flavor on the grill. Smoked casings also work wonderfully for smoked sausages as they double down on the signature taste.
Since smoked casings are heat-treated, they’re more durable than regular, fresh casings. This allows you to stuff them a bit more or keep them in the smoker for longer without fear of falling apart.
Dry Collagen Casings
Dry collagen casings have a lower water content than their fresh counterparts. They’re firmer, more rubbery, and rigid in comparison to other kinds of casings.
Since they’re dry and snappy, smoked casings are the perfect fit for:
- Pepperoni
- Salami
- Snack sticks
- Other, similar kinds of sausage
However, certain dry collagen casings are inedible, so be sure to check and label your products accordingly before digging in.
Why Collagen Casings Are Popular
Collagen casings have been gaining popularity in recent years and are quickly becoming an industry favorite. Why? They’re:
- Visually appealing – Collagen produces a clean, glistening sheen on the surface of sausages that tempts hungry palates without imparting much in the way of flavor.
- Tender – Collagen casings vary in texture between fresh, dried, and smoked versions but, all in all, they’re soft and slightly snappy in comparison to the firmer, more chewy feel of natural casings.
- Easy to work with – Collagen casings don’t require any pre-soaking and come untangled in tidy packages. This saves significant time and effort and makes them easy to use with commercial stuffing equipment.
- Prime for portion control – Since they’re so easy to work with, it’s simple to stuff collagen casings to the exact size you want. That means minimal waste, less give-away, and more profit in your pockets.
- Safe and edible – Above all, collagen is a safe and healthy product that’s not only used in casings, but also in many foodstuffs, cosmetics, and more.
- Available in different varieties – Whether you’re making fresh sausage, a smokey aged weiner, or a snack stick, there's a collagen casing to match your recipe.
- Permeable to water and smoke – This lets you steam, boil, or smoke your sausages to your heart’s desire to get the exact flavor you’re after.
From humble hot dogs to brilliant bratwursts, collagen casings can be used in almost any kind of sausage. If you’re making the switch from natural, ensure you get your casings from a reputable, reliable supplier like Oversea Casing.
Secure High-Quality Collagen and Natural Casings from Oversea Casings
Collagen casings are produced from treated cow and pig skin along with other connective tissues. They’re safe, relatively flavorless, easy to work with, and produce a soft but snappy bite that your customers are sure to love.
Whether you work with collagen or natural casings, high-quality products are key to creating the best-tasting sausage possible. That’s why for nearly 100 years, Oversea Casing has been supplying the world with premium sausage casings of all sizes and styles.
Shop collagen casings and more to find the perfect companion for your sausage needs.
Sources:
Harvard Health. Collagen. https://nutritionsource.hsph.harvard.edu/collagen/.
International Journal of Biological Macromolecules. Comprehensive review on collagen extraction from food by-products and waste as a value-added material. https://www.sciencedirect.com/science/article/pii/S0141813024051791.
Australia New Zealand Food Authority. SORBIC ACID IN EDIBLE COLLAGEN CASINGS. https://www.foodstandards.gov.au/sites/default/files/food-standards-code/applications/Documents/A419%20FAR.pdf.