Our Lab-Grown Sweater is the start of a ground-breaking new way of making materials. It’s built with lab-grown fibres that don’t start life like any material currently used in clothing. It doesn’t come from plants like cotton or linen. Or from animals like wool or cashmere. And it’s not a plastic like nylon or polyester either. Instead it’s a totally new type of biomaterial made with molecular engineering.

In 2004, Kazuhide Sekiyama and Junichi Sugahara, were students at Keio University in Tokyo studying bioinformatics. It’s a discipline at the intersection of computer science and biology – where complex biological data like DNA, RNA, and protein sequences are collected and analysed. And it was here, in their university lab, that they started exploring how to recreate spider silk.

While Brewed Protein™ is made by replicating many of the processes we see in nature, it brings together a combination of molecular structures to create a fibre that’s not only completely new, but unique in the material world. In terms of its molecular composition, how it feels on your skin, and what it can do, it sits somewhere between cashmere, wool and silk – three of the softest, highest-performance natural fibres on Earth.

Like any new technology, we’re still discovering the potential of Brewed Protein™. So at this stage in its journey we’ve found it works best when combined with a couple of other fibres for strength and stability. So we blend our protein fibre with wool in Japan to create a soft but strong single yarn. Then we combine this with a second yarn made from Merino to build the final sweater. While the aim is to grow an entire sweater in a petri dish, we have to wait a little longer for that.

The sweater is fully reversible to make the most of the crazy honeycomb patterns, textures, and lab-grown aesthetic. And we’ve designed it as a mid-weight sweater you can wear on its own in warmer weather, or as a layering piece during winter. Whatever way round you wear it, it’s incredibly soft. The biomaterial feels like a cross between cashmere, wool and silk, and the Merino wool we blend it with is also incredibly soft.

Up until we came along to disrupt the industry, 99.999% of all clothing in the history of our planet was made from 3 things – plastics, plants and animals. Over the last 5 years we’ve been changing that – pioneering clothes built with copper, graphene, aerogel, stainless steel, ceramics, carbon fibre, Dyneema®, phosphorescent compounds, minerals, and hypersonic space parachutes. But until today we were missing our first molecularly engineered biomaterial – a new vertical that will turn how clothing is made on its head over the next decade.  

Nature has been perfecting biomaterials like skin, nails, hair, wool and spider silk for the last few billion years. And the organic processes that make these materials are so complex they’ve been almost impossible to replicate. Until now. After 20 years of R&D, Spiber have figured out how to grow biomaterials in lab conditions, by programming microorganisms with protein DNA from animals and insects.

Proteins like fibroin, keratin and elastin are the fundamental building blocks of materials like spider silk, wool and skin. So to recreate biomaterials you need to be able to produce proteins. And thanks to Spiber’s pioneering work, we’re now able to recreate protein evolution in controlled lab conditions to grow new fibres. While this used to take millions of years, it can now be done in months.

The first step of growing novel biomaterials starts in Japan, where Spiber’s engineers use genetic databases to search for proteins with specific properties in the DNA of living organisms. Portions of DNA sequences are then picked out from hundreds of different animals and insects – from sheep and squid to spiders and crickets.

This DNA is then reproduced in Spiber’s lab before being injected into thousands of tiny microbes – a process called microorganism programming. Once they’ve been programmed with the protein DNA, the microbes start rapidly reproducing it as they multiply. And just in case you’re wondering, these microbes are engineered to only survive in the lab, so there’s no risk of a catastrophic biohazard leak.

After the microbes have been programmed with the protein DNA they’re fermented just like you would ferment wine or bread. They’re placed in giant stainless steel tanks with sugars, which they transform into a protein polymer. This fermentation stage happens at Spiber’s industrial facilities where all of the sugar used is from sugarcane certified by Bonsucro, a non-profit organisation ensuring that sugar is produced in a sustainable and traceable way.

Finally the protein polymer is liquid-purified and dried down into powder. The powder is dissolved into solvent and extruded through nozzles into water, leaving behind an ultrafine protein fibre that can be spun, knitted and woven into fabrics.

Around half of the sweater is made from high-performance Merino wool, which is an incredible material in its own right. Merino sheep are bred to survive scorching summers and freezing winters, so the fibres of their wool respond and adapt to the conditions you find yourself in – either trapping or releasing heat depending on the temperature and humidity of your skin.

The outside of every Merino fibre is covered in a natural wax coating which makes it water repellent. At the same time the Merino acts like a sponge to soak up sweat and spread it over a massive surface area so that it evaporates at high speed. As Merino can absorb over 30% of its own weight in water and still feel dry, you’ll stay warm and insulated. And it’s also odour resistant as odour molecules are absorbed and locked into the centre of the fibre, and only released when you wash them.