From Dead Pig to New Sweater

How fibers are being made from slaughterhouse waste

White and red spools of gelatin yarn on toilet paper rolls
The gelatin fibers all wrapped up nicely. You’d have no idea what they started out as! (ETH Zurich)

How to Make It

Making the fibers is actually quite simple. You could even make them at home! (Just leave out the chemicals ;))

1. Potions Class (make the dope)

Combine gelatin, water, and isopropyl alcohol in a sealable container at 50 degrees Celsius. Mix or shake it every now and then. After 30 minutes to an hour the mixture will separate into two distinct layers.

Three tubes with separated spinning dope
The white stuff on the bottom is our gold 💰 (ETH Zurich)

2. Squirt it out and s t r e t c h

There are two different methods you could use here. On a high level, they’re both just taking the dope and stretching it out really long and skinny. I’ll explain the similarities and differences between them, but first I think it’s time for…

Stretching 101

You might be wondering: How on earth are you supposed to stretch a sticky blob, Klara? Why, I’m glad you asked! You could point the spinning nozzle to the ground and have gravity do the work for you. That’s the easiest way. But you won’t be certain how much stretch factor is being induced.

The string hanging down with a weight attatched
A gelatin string from 10 filaments at 2x stretch easily holds a 140 g (5 oz) weight (ETH Zurich)

Dry vs. Wet

Dry-spinning is the most straightforward (especially if you want to do this at home). Put the precipitated protein (white blob) in a syringe, squirt it out, and stretch it using one of the techniques above. Keep stretching it as long as you would like and if it’s still wet by the time you finish, let it air dry.

The fibers’ center with lots of pores
A cross section of the fiber. Look at all those pores LOL (ETH Zurich)
Thin gelatin threads on a black ethanol soaked roller
The white threads on a black, wet roller. That’s how thin they are! (ETH Zurich)
A diagram of the spinning process
The wet spinning process. (ETH Zurich)

Cross-linking and Extra Treatments

All sounds great, right? Well, the fibers are great on their own…but there are some drawbacks. Gelatin is super water soluble (like really really) so when the fibers get too wet they swell and dissolve. It’s also not the strongest which is a problem if you’re going to be making clothes with it.

The gelatin mitten submerged in a glass of water
Just in case the mitten wearer falls into a pond, Stössel is prepared :) (ETH Zurich)

🐰 and Possible Applications

In a way, gelatin fibers mimic those of an angora rabbit. Angora rabbit fur is one of the highest quality, most sought after fibers in the textile industry. Most animal fibers, like sheep wool, have little overlapping “scales” which make them matte. Angora rabbit fibers don’t.

A fluffy tan angora rabbit
A duster *ahem* angora rabbit. (Animalogic)
Gelatin fibers shine in the light
Silky fibers, minus the bunny (ETH Zurich)
The identical gelatin mitten next to the merino wool mitten
The shiny gelatin mitten on the left, next to the matte merino wool mitten on the right. (ETH Zurich)

Key Takeaways

  • A PhD student developed a method of producing fibers from gelatin, an abundant slaughterhouse waste product
  • The fibers are simple to make and don’t require much equipment
  • They have many of the same properties as angora rabbit wool
  • Gelatin fibers are naturally insulating because of their porous structure
  • They don’t perform well when wet and chemicals are needed to make them water-resistant

Sources and Further Readings



Passionate about the future of food and the environment. Likes animals too :)

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Klara Zietlow

Passionate about the future of food and the environment. Likes animals too :)