AllBirds is Making Sustainable Shoe Soles from Sugarcane


On Thursday, Allbirds finally — after three years in development — adds a third sustainable material in “SweetFoam,” a proprietary sole material that’s derived from renewable sugarcane. The journey to SweetFoam began when the Allbirds team quickly grew dissatisfied with the range, or lack thereof, of eco-rooted, non-petroleum-based options available in shoe soles.

“We’ve always known from day one that one of the weakness we’ve had from a sustainability perspective is the bottom of the shoes,” Zwillinger told Fashionista in a cross-country phone call.

When Allbirds as we know it was still in its infancy, Zwillinger and Brown began contact with a Brazilian petrochemical company called Braskem. In their initial pitch, the Allbirds team relayed their vision of creating both a brand-new polymer and subsequent foam out of sugarcane. (“We knew that sugarcane was the most environmentally responsible, self-sufficient carbon source, pretty much on the planet, that you could find,” said Zwillinger.) After a courtship period, Braskem eventually signed on to help invest in and partner with Allbirds to make SweetFoam a reality.

The physical sugarcane at the root of SweetFoam comes from dense, rain-drenched fields in Southern Brazil. In its growth, it’s treated with minimal fertilizer and later, processed in facilities that are run entirely on renewable power, making SweetFoam the planet’s first carbon negative EVA polymer.

How does the sugarcane physically become SweetFoam? The sugarcane is processed in a sugar mill, during which point the purest portion is removed and sold as refined table sugar while the waste product, called molasses, is treated. From there, the molasses is put into large stainless-steel tanks along with a yeast, which metabolizes the sugars within the molasses and coverts it into ethanol. Then, through a number of other chemical processes, that ethanol is translated into EVA, which Allbirds takes and mixes with a “special blend” to make the end product — SweetFoam — more comfortable. 

Analysis: This Article shows how big businesses are trying to become more sustainable. Even AllBirds, a company obsessed with being the most sustainable they can be, are working on new soles made from more organic materials while trying to limit a shoe soles carbon footprint.