Spiber is no longer a competitor. They used to be, but not anymore.
Just like when Bolt Threads finally figured out that isolating just the spider silk protein from yeast is prohibitively expensive for clothing. Both companies used the same process. Bolt decided to completely pivot and shift towards mushroom leather. Spiber, instead, decided to sell the protein broth without isolating the spider silk proteins.
Purifying the proteins that the yeast produce (hint: they excrete thousands of different proteins into the medium along with the spider silk analog), is an extremely expensive part. Their original idea was to purify the resulting broth and extract the protein through many stages of centrifuging. The first step in purification is the easiest. It removes most of the suspended solids. Next comes removing the dead and lysed yeast cells. After that, the next couple dozen rounds of centrifuging will be used to separate all the remaining thousands of different types of proteins that yeast use for different metabolic purposes, and purifying it to get a high percentage of spider silk protein analog. Even once they get it to 90% spider silk protein analog, they will need many more rounds of centrifuging. The last few percent are the hardest. This is why insulin is relatively expensive to make (in mass quantities, not expensive for the minuscule amounts needed for drug purposes).
This was one of Spibers biggest issues. In order to make a fiber with even close to comparable mechanical properties as spider silk, they were going to need to isolate it which would be way too expensive for garments. This is why they pivoted to "brewed proteins". Because thats exactly what it is. All they do now is do the first couple steps of purifying in order to remove suspended solids and the dead yeast, and then they dehydrate ALL of the proteins secreted by the yeast. They make a fiber with this "brewed protein". But they could also make a fiber without the trace amounts of spider silk in it. It's not hard to make a fiber from any protein, however, it won't have any useful characteristics so you might as well use something cheaper, like cotton or wool.
Spibers main selling point now is that they are sustainability advocates who make a fiber without traditional agriculture or fossil fuels. They are no longer going after the high tech fibers with incredible mechanical properties. This is why they are no longer a competitor of Kraig Labs.
Kraig Labs uses a silkworm which has specialized silk glands. In normal silkworms, these glands only produce and excrete the very few proteins needed for the structure of its silk. Most notably the 2 heavy chain proteins (about 70%), the light protein (5%), and sericin (25%). The early fibers that Kraig Labs made simply added spider silk proteins to this mix. Somewhere less than 10% of these original fibers was spider silk, but it still gave the new recombinant silk much better properties than regular silk. The Newest Dragon Silks that Kraig Labs announced a couple years ago didn't just ADD spider silk proteins, they REPLACED the 2 heavy chain silkworm silk proteins with spider silk. They only left the minor light protein and sericin on purpose for structural reasons. Once the silkworm makes the fiber, and the sericin is washed away, you are left with more than 90% of the heavy chain spider silk protein, and the rest is the light chain protein for structural purposes. Nothing else. Unlike the fermentation method which has thousands of different proteins in the mix which effect the mechanical properties.
TL:DR - Spiber is no longer a competitor (just like Bolt Threads). They are going after 2 different markets now.
